PROCEEDING OF THE 6th International Conference on Flood Management - ICFM6

"Floods in a changing Environment"

September 16-18, 2014 - São Paulo - Brazil

 

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Flood Zoning of Golestan Dam Downstream Plain in Iran (PAP014018) - Full Paper
Keywords: Flood, Zoning, HEC-RAS, ArcView, Golestan Dam
Subject: Urban Floods
Abstract:
Flood is a complex natural disaster and destroying phenomenon that causes considerable annual damage. In addition, floodplain and lands alongside river beds are always in expose of flood hazards, while most of economic and social activities are conducted in these areas. Therefore, in these regions, flood zoning is necessary. Flood zoning maps, could be a suitable and lawful tool for determination of development strategies. In this research, the map of flood zoning with different return periods for a part of Gorgan Rood River, Iran was provided. Hydrological data and information were collected and analyzed. Flood routing by using Muskingum-Cunge method in different reaches was conducted. These data were used in the HEC-RAS model and its report was extracted. Finally, flooding area and flow depth in different return periods were determined. The accuracy and precision of flooding maps were evaluated by comparison with information and local investigations. The results show that by considering the HEC-RAS limitations (reach shortness), the final flooding maps are accurate enough for the aim of this kind of study.
Flood Vulnerability Assessment in Tehran City (Iran) (PAP014309) - Full Paper
Keywords: Flooding, Vulnerability, Tehran City, Analysis Hierarchical Process
Subject: Flood risk management in mega cities
Abstract:
Vulnerability assessment of urban areas against flooding, as a complicated hazard, in Tehran City has been conducted in this research. The flooding has temporal and spatial variability and also increasing trend with enormous financial and life damages. Occurrence of the flood hazard is greatly dependent upon natural conditions, characteristics of urban areas, and also the culture of society. The objective of this research is to find a pattern for the differences of the vulnerability in the urban areas. Variables of old texture blocks, population concentration, land use, and distance to bridges as physical agents and variables of slope and drainage network density as intensifying agents have been included for the analysis. The variables have been prioritized and the relations between these and the vulnerability determined by Analytical Hierarchy Process (AHP). The agents of population concentration and drainage network density have been revealed to have the highest and the lowest weights, respectively. The results have indicated that the regions of 10, 17, 8, and 11 are the most vulnerable and the regions of 22, 21, 18, and 5 are the least vulnerable. The vulnerability map indicates that 138 square kilometers of Tehran area is categorized as very high and high vulnerable. Based on the results from zonal statistic, regions of 10 and 22 have the highest and the lowest vulnerability, respectively. Greatly vulnerable areas are coincident with highly populated regions of old textures.
Urban Flooding and Ground-Related Homes in Canada: An Overview (PAP014310) - Full Paper
Author(s): Dan Sandink
Keywords: Urban Flooding, Canada, Private-Side, Municipal-Side, Insurance
Subject: Urban Floods
Abstract:
Urban flooding associated with extreme precipitation is a significant cause of disaster damages for municipalities, homeowners and insurers in Canada. Over the past few years, Canadian insurers have seen dozens of individual urban flood events that have resulted in millions of dollars in payouts. Losses associated with urban flooding are expected to increase over the coming years as a result of increasing urbanization, deteriorating infrastructure and the expected impacts of climate change on precipitation regimes across the country. Several approaches have been applied to reduce risk associated with urban flooding at the municipal and homeowner scales, including limiting excess water contributions to municipal sanitary sewer systems, accommodating extreme stormwater flows in subdivision design, and protecting individual homes from flooding. Insurers have also become engaged in managing this risk through interactions with individual policy holders, and have been involved in a number of initiatives aimed at better understanding urban flood risk and risk mitigation options in Canada.
Reducing Urban Flood Risk in Canada Through Code Interpretation (PAP014311) - Full Paper
Author(s): Dan Sandink
Keywords: Urban Flood, Inflow and Infiltration, Sewer Backup, Canada, Building Code
Subject: Urban Floods
Abstract:
While it has been previously reported that resolution of building code enforcement issues may result in reduced vulnerability to extreme natural events, issues surrounding code interpretation have not previously been studied. Among other topics, this study investigated interpretation of code wordings that relate to installation of backwater valves to protect homes from sewer backup—a significant cause of basement flooding associated with extreme precipitation events and urban flooding in Canada. Despite consistent application of code wordings related to backwater valves across the regions of Canada represented in this study, it was found that there are differing interpretations of code wordings, which resulted in differing reported frequencies of installation of backwater valves on both sanitary/combined and storm sewer service connections.
Flood Alleviation Design: Adopting a Social Perspective (PAP014321) - Full Paper
Keywords: Flooding, Infrastructure, Social value, Flood alleviation, Design
Subject: Flood risk management in mega cities
Abstract:
The argument presented here calls for an approach to flood infrastructure design that considers not only the need for a technical perspective in design but a social perspective as well. This paper examines the preliminary findings from research that seeks to understand how the social value of UK flood protection schemes is interpreted and discussed by both communities and industry professionals responsible for flood infrastructure design. The preliminary findings are taken from a case study conducted between October and December 2013 in Ripon, UK. A series of semi-structured interviews were conducted with both the community and design professional responsible for the local flood protection scheme. The findings presented will demonstrate how social value is articulated and if a difference in interpretation exists between the communities it is designed for compared to the industry professionals that design it. The conclusions drawn from the preliminary research corroborates the argument that adopting a social perspective in flood infrastructure design produces not only a technically successful scheme, but a considered and socially acceptable scheme. This is an approach which should be adopted for future flood infrastructure design as more communities around the word are exposed to the very real risk of flood events. As a result of climate change and changing weather patterns, it is predicted that more intense rainfall will be experienced with rising sea levels due to increased precipitation. This results in a greater number of people across the world at risk and vulnerable to flood events, which will consequently mean the demand for flood protection infrastructure will also rise. Aspects of flood risk management such as flood protection schemes are not only critical for the protection of lives and properties, but also for economic growth. The presence of these schemes can unlock the economic potential of an area, attracting investment and employment opportunities. The benefits to both the local and national economy are numerous. However, flood infrastructure design as with most infrastructure design, is very much focused upon technical aspects and cost-effective solutions. Previous work, both in academia and industry have concentrated upon examining the complexity of infrastructure from a number of perspectives including: the physical structure itself, technical characteristics, governance and institutional arrangements and the financial mechanisms adopted for construction and operation. Infrastructure that is designed for the purpose of protecting society may not even be considering society in its design and less effort has been focused upon understanding the characteristics of the resultant services created. This is of concern because it indicates the possibility that flood infrastructure schemes may be developed without due consideration of the end user as design teams work in silos to provide technical solutions to what is, essentially, a social problem. Design teams neglect to consider how the communities hosting the physical infrastructure use the existing space; namely how they interact with the infrastructure once created and how they will utilise the space when there is not a flood event.
Ensemble Prediction of Flood Maps Under Uncertain Conditions (PAP014328) - Full Paper
Keywords: Uncertainty, Flood risk, Ensemble, Flood map, Model cascade
Subject: Floods in a changing climate
Abstract:
Flooding is the most common and damaging natural hazard faced by civilization, and flooding threats are likely to increase given current climate change predictions that suggest more intense hurricanes and precipitation. Flood events observed in developed and developing nations alike, highlight the necessity to generate a better understanding on what causes extreme flooding events and how we can better manage flood risk. Moreover, the process of flood risk evaluation and management contains a great deal of uncertainty, which in turn is ascribed to the limitations in the current body of knowledge. Thus, it is necessary to somehow consider and inform how current limitations in the knowledge affect a given prediction. Therefore, it is anticipated that quantification of these uncertainties and their propagation through to modelling process is of great importance. Having this in mind, the work in this paper aims to develop a cascade modelling approach for the generation of more reliable and useful flood maps. This involves the use of a Numerical Weather Model (NWP), a rainfall-runoff model and a standard 2D hydrodynamic model. Uncertainty is considered in both the meteorological and hydrological models through the estimation of ensemble precipitation scenarios and spaghetti plots, respectively. The characterisation of the runoff by multiple possibilities, opens the door to a probabilistic estimation of affected areas, which in turn allows the evaluation of uncertainty propagation to an estimated flood map. The methodology is enriched with the use of field data of high quality, comprised by a data from a field campaign, automatic gauging stations and LiDAR data for an accurate representation of topographic elevation. The presented approach is useful for both, the reduction of epistemic uncertainties and the generation of flood management strategies through probability flood maps. The approach is applied to a region of Mexico with the highest precipitation rate, expecting that generated results would be useful in the design of more effective flood management strategies.
Hydrodynamic Modelling of a Large River and Floodplain: Usumacinta, Mexico (PAP014329) - Full Paper
Keywords: Usumacinta River, Hydrological uncertainty, Large-scale modelling, Floop map
Subject: Floods in a changing climate
Abstract:
This investigation presents an integrated study for the identification of affected areas due to extreme flooding observed in the largest river of Mexico. In years 2008 and 2011 catastrophic events were registered due to heavy rainfall leaving a great social disruption and large economic damages. These recurring impacts, indicated the need of a practical approach to enable better decision making and a more efficient management of these events. The selected approach is designed to reduce some of the uncertainties in the results, and is comprised by high-quality field measurements, hydrologic and hydraulic numerical models, RADARSAT images and LiDAR data. A 30m digital elevation model and historical flooded areas for the year 2011 were extracted from a LiDAR data set and RADARSAT images, respectively. Hydrologic information was constructed from precipitation data obtained from the Mexican National Water Comission, and validated using gauging stations along the Usumacinta River. For the whole measurement period, results in terms of the hydrographs and flooded areas indicated a good agreement between numerical and measured data. This study demonstrates that the use of high-quality input data, in combination with a 1D hydraulic model, provide an adequate set-up for the identification of vulnerable areas to flood events in large-scale basins.
The Role of Hydrological Uncertainties in Flood Risk Analysis: Tonala River, Mexico. (PAP014330) - Full Paper
Keywords: Food risk, Uncertainty, Cascade modelling
Subject: Floods in a changing climate
Abstract:
Around the world, there is a scarce mention of the role of the different sources of uncertainty duringthe assessment of flood risk. Given the magnitude of the stakes at risk during the incidence ofextreme events, it is necessary to somehow consider and inform how uncertainties may modify agiven prediction. As a result of the necessity to make decisions in the light of uncertain scientific input,this is especially true in the flood risk analysis process, where the lack of accuracy in the results mayinduce significant deviations and mistakes.Within this context, the aim of this work is to present a practical framework for flood risk analysis,where the Source-Pressure-Response-Consequence model is used for the assessment of bothprobability and consequences due to flooding. For this, two methodological units are introduced, oneaimed at the hazard characterisation and mapping and other related to the holistic characterisation ofvulnerability. The first is carried out by means of an integrated approach comprised by a cascade ofmodels; a distributed hydrological model and a standard 2D hydrodynamic model. While for thesecond part, the vulnerability of the system is dissected in five dimensions: physical, social, economic,ecologic and cultural. It is reflected that this enables the characterisation of the vulnerability in terms ofboth the degree of exposure and the fragility of the system to flooding. Uncertainty is considered inthe hydrological model through the estimation of possible hydrographs for a given rainfall. Thecharacterisation of the runoff by the multiple possibilities opens the door to a probabilistic estimation offlood maps.
Levees in a Changing Environment: Flexible, Strategic Planning (PAP014331) - Full Paper
Keywords: Flood Risk Management, Spatial Planning, Levees, Prevention, Adaptive strategies
Subject: Floods in a changing climate
Abstract:
Water is wonderful and the Dutch love it! Yet there is much work to do. Now is the time to invest in plans to ensure the future safety and livability of the Netherlands. Implementation of several flood protection measures is already in full swing, with more flood safety programs scheduled to be executed over the following decade. However, the limits of the current approach have almost been reached. The Netherlands is already densely populated, while climate change leads to increased flood risk of highly vulnerable areas. The cost to implement measures is increasing, with available resources being under pressure. It is clear that innovations in addressing flood protection measures are necessary. In order to be able to anticipate potential floods by means of effective and efficient protection measures, a more integral approach is required. In other words, a combination must be made between flood protection and spatial developments/interventions. We observe that the current approach of dike reinforcements suffices for the time being, but is nevertheless sectoral. Nor is it sufficiently robust for the long term. Opportunities to integrate flood safety measures with other spatial plans seem few and hard to materialize. Processes and time periods are different between the two. In addition, policy making in public (national versus local) and public-private partnerships are hindered by steering (legal) frameworks, complex organizations (programs, projects) and a risk-averse attitude. There is an urge for more insight into the possibilities for an integrated and flexible approach to dike reinforcement in both time and space. A framework enabling multifunctional levees, as part of this integral and flexible approach, has been developed and analyzed on the basis of several cases within the Netherlands both in urban and rural areas. In this paper this framework is addressed and more insights are given into new flexible strategic planning processes for both flood risk management and spatial planning.
Adaptive Flood Risk Management for Unbanked Areas in Rotterdam, the Netherlands; Co Creating a Legitimate Strategy for Climate Robust Planning (PAP014332) - Full Paper
Keywords: Flood Risk Management, Co-creation, Adaptive strategies, Knowledge
Subject: Flood risk management in mega cities
Abstract:
Changing climate conditions have major consequences for the unembanked parts of cities in the low-lying Dutch delta. Cities like Dordrecht, Almere and Rotterdam are therefore busy to rethink their local flood risk and spatial planning strategies. In Rotterdam the city government decided in 2010 to rethink flood risk approaches for unembanked areas. The current strategy (to formally oblige elevating ground levels in case of new developments) will not suffice and would be too expensive in the long term. In the last years research was conducted on the region Feijenoord. Within the unembanked area of Feijenoord, Noordereiland and the Kop van Feijenoord are most vulnerable to flooding. Both areas have low ground levels, are expected to flood frequently, and house vulnerable functions on the ground floor. The spectrum of flood adaptive measures, ranging from organisational to physical measures are summarised in a ´toolbox ´. Private parties are responsible for most of the small-scale measures whereas public authorities are generally responsible for measures on the district-scale. Stakeholder participation to create an adaptive strategy is imminent. The toolbox led to the identification of possible strategies for flood risk management. This two strategies lead toIn this paper a description is given on how, from the start, these adaptive strategies for flood risk management are co created with all relevant stakeholders. In different stages of this research, different interdisciplinairy teams were involved. This process led to the formulation of new research questions. More insight is given in how the adaptation tipping points research resulted in the two leading adaptive strategies. Three steps were identified which lead in the end to a long term adaptation strategy. All three steps will be (briefly) described in this paper. The so-called adaption pathways were developed. This formed a base for drafting two adaptive flood risk management strategies. Co creation already took place in this stage, although not all stakeholders were part of this stage. Last but not least a governance strategy was co-created with stakeholders which has to enable the implementation of these strategies. In this paper we answer the question in which factors influence the success of using co-creation with local stakeholders to develop adaptive flood risk management strategies.
Foresight Evolution Trend of Flood Risk in the Taihu Basin and Its Proper Adaptation Strategies (PAP014333) - Full Paper
Author(s): Xiaotao Cheng and Haoyun Wu
Keywords: flood risk, global warming, urbanization, scenario analysis, adaptation strategies
Subject: Flood risk management in mega cities
Abstract:
Taihu basin, located in the estuary areas of the Yangtze and Qiantang rivers, is one of the most important economic regions in China. It is easy to suffer from serious flood disasters caused by plum rains, typhoon and storm surge. Features of flood risk in the Taihu basin are very sensitive to both global warming and rapid urbanization. In order to provide the decision-making basis for adjusting flood management strategy in the Taihu basin, a flood risk scenario analysis system has been developed by joint efforts of China and UK experts from 2007 to 2010, consisting of a series of models of climate change impact analysis, social economic development forecast, flood losses assessment, hydrological analysis, flood simulation, dyke reliability evaluation and GIS based system integration. The results show that the flood risk growth will be faster than the economic growth in the Taihu basin during 2030 to 2050 because of the combined efforts of global warming and urbanization if we just continue the current flood control measures. The study has got continuing support by the National Key Technology R&D Program for the 12th Five-year Plan to explore the proper adaptation strategies. The presentation will introduce the progress of this research project.
Principles of Sustainability as Guidelines of Actions for the Solution of Stormwater Management Related Problems (PAP014335) - Full Paper
Keywords: Urban Problems, Sustainability Principles, Stormwater Management, Sustainable Urban Draining
Subject: Urban Floods
Abstract:
The objective of this work was to establish specific principles qualified of guiding administrators in making decisions related to stormwater problems, and, specifically guide them to continue this work and the development of sustainability indicators for stormwater management. As methodology, in order to establish specific principles for stormwater management, the goal was to search for general principles about sustainability, disparately present in literature, which, most times, present generic and open characters, being qualified of application in any situation or place. From the search results, there was a re-reading and interpretation of the generic principles, searching its adequacy to problems related to urban stormwater. We can see the same methodology for raising issues. As a result, we could issue thirty-six related problems and thirteen principles, which are specific to stormwater management and from the results obtained in the survey; we were able to make correlations of the principles, which were able to lead actions related to the respective problems. This way, we could conclude that it is possible to use these specific principles in different situations, as orientation in the elaboration of public policies and in the development of sustainability indicators, aiming at enhancing the planning and support of decision-making. They will also be useful for orientation to the next phases in the project, in the elaboration of sustainability indicators, targeted to stormwater management.
Study on Changes of Rainstorm Days in Different Regions of China in the Recent 50 Years (PAP014338) - Full Paper
Keywords: Analysis and Comparison, Change Characteristics, Different Regions of China, Rainstorm Days
Subject: Floods in a changing climate
Abstract:
Using daily precipitation data of 601 stations from 1961 to 2010 in China, the changes of rainstorm days in different regions of China were analyzed and compared based on Mexican Hat wavelet and mathematical statistics. The main results show that the annual rainstorm days increased during the recent 50 years in most regions of China, and the amounts of increase were significantly greater than that of decrease. The annual rainstorm days increased mainly in the Lower Yangtze-Huaihe areas, the south of the Lower Yangtze River, Guangdong Province, Guangxi Zhuang Nationality Autonomous Region, Hainan Island, etc. In these areas, the risk of meteorological and geological disasters such as flood inundation, mud-rock flow, landslide, etc. were increased. After 2010, the annual rainstorm days and the risk of rainstorm disaster will possibly increase in most regions of China. Some research results in this paper provide important information of climate background for analyzing and evaluating disasters of flood inundation, mud-rock flow, landslides, etc.
Risk Financing and Risk Reduction - a Comparison National Arrangements Across Developed Countries and Specific Lessons From Austria 2002-2013 (PAP014340) - Full Paper
Keywords: Risk financing, Flood insurance, Flood protection, Austria, Country comparison
Subject: Flood resilient societies through community preparedness
Abstract:
In the face of more frequent and intensive storms and floods insurance arrangements are becoming an increasingly important tool not only to address risk averseness, but also to incentivize risk mitigation and adaptive behavior. Indeed governments are looking to create new insurance arrangements or reforming existing ones. Contrary to existing literature claiming that there is no one-size-fits-all solution, we find that there are indeed design choices that can be found more and more frequently across risk-transfer systems and which seem applicable in different contexts: (1) Bundling of catastrophe risk with more standard homeowners’, fire or accident insurance. (2) Private administration and public regulation of insurance; And (3) quasi risk-based premiums with some form of equity mechanism through some form of subsidy. We use a discourse analysis for the case of Austria, where above mentioned features are part of a high level discussion, but so far failed to gain traction and thus being implemented. We find that hierarchical thinking is deeply ingrained in almost all stakeholder groups. While successful flood protection is celebrated, individual awareness of the limits of public protection residual risks is missing and might cause unpleasant surprises in a climate change future.
Integrated Modeling Approach to Simulate Hydrologic Process in Urban Watersheds (PAP014345) - Full Paper
Keywords: water balance, flood, catchments, Metropolitan Region of Belém
Subject: Urban Floods
Abstract:
Correct prediction of flood extents in urban catchments has become a risk issue especially in Amazon region where is located a vast drainage system associated to intense rainfall. The traditional approach focused in arranging channels, with the objective to minimize the flood effect can be in an initial moment, the better solution able to deal with floods in a certain area, without major consequences. However, the urban growing especially in expansion zones implies in significant stresses on the watersheds. Therefore, the better response is to try understanding how urbanization interferes in the flow patterns and the urban water environmental support capacity. The main purpose in this paper is simulate a set of physical attributes in watersheds with limited self-adjusting capacity in urban expansion areas associated to the process of urban growing in Metropolitan Region of Belém (RMB, Pará-Brazil). The study area, with about 123 km², is a zone of the economic and urbanization development, situated between the Guamá River and Guajará Bay, making part of the Amazon River estuary. The lowlands wet are the typical environment where occurs two major process: urban pluvial flooding, as a result of run-off accumulation and fluvial flooding as result of overflowing of river banks. In this work were employed the conceptual model (mathematical) and based on the attributes of the physical environment. In the characterization of the rainfall (13 years) were used: average monthly, cumulative annual, return time and probability distribution based on the methods of Ven Te Chow, Log-Normal, Log Pearson Type III and Gumbel, and in the simulation of the values of discharge was adopted the method of SCS (Soil Conservation Service). In the physical characterization of the watersheds was employed: geological units, terrain units, altimetry (digital elevation model) and morphometric elements. Were used several method for linear, areal and relief aspects studies, such as, Stream Order, Slope, Drainage Texture, Drainage Density, Hydrographic Density, Topographic Texture, Maintenance Coefficient, Channel Gradient, Infiltration Number and Bifurcation Ratio. In the analyzed period, the wettest years were: 2006 (3664 mm) and 2011 (3592 mm). The return time for 05 years considering the methods of Pearson Log-type III (3542 mm), Log-Normal (3537 mm), Ven Te Chow (3533 mm) and Gumbel (3497 mm) imply in a high probability of recurrence of periods of flooding. The SCS method (Soil Conservation Service) indicated the largest flows are expected in Una basin (3.81 m³/s), Black Water Lake basin (1.79 m³/s) and Val-de-Cans basin (1.15 m³/s). The simulation model was capable to incorporate all the drainage elements and their interactions properly, for an accurate prediction of urban flooding. The continued monitoring of rainfall in association with the physical parameters controlling the processes that occur in watersheds can provide a more effective flood prediction, useful in the urban flood disaster prevention system.
Agricultural Flood Risk Assessment in China at the Provincial Scale (PAP014346) - Full Paper
Keywords: Agricultural Flood Risk, Grey Correlation Analysis, Soft Histogram, Provincial Scale, China
Subject: Floods in a changing climate
Abstract:
Based on the annual crop area covered by flood disasters and annual crop area affected byflood disasters and annual sown area of crops from 1971 to 2010 in each province of China, agriculturalflood risk in China was assessed at the provincial scale using the soft histogram method. Firstly, theagriculture disasters were classified to five grades according to the percentage of crop area covered byflood disasters and crop area affected by flood disasters respectively. Then a comprehensive agriculturalflood index was developed based on the above two indicators using grey correlation analysis method.The probability of agricultural flood disasters of five grades was calculated using the soft histogrammethod. Finally, the agricultural flood risk of each province in China was assessed using the weightedsum of the probability of different disaster grade.
Numerical Modeling Methodology and Techniques for the External Flooding Analysis of Ascó and Vandellós Ii Spanish Nuclear Power Plants, During Stress Tests (PAP014349) - Full Paper
Keywords: PMP, Nuclear Safety, Stress Tests
Subject: Urban Floods
Abstract:
Considering the accident occurred at Fukushima Daiichi Nuclear Power Plant in Japan, the European Council of March 24-25, 2011 stated that “the safety of all EU nuclear plants should be reviewed, on the basis of a comprehensive and transparent risk assessment (“stress tests”)”. In this context, the WENRA (Western European Nuclear Regulators Association) established the technical contents of the stress tests and how they should be applied to all nuclear facilities across Europe. One aspect of the stress tests is related to External Events. This includes fluvial flood risk or severe local precipitation on the plant site. The purpose of this article is to describe the methodology used by ANAV, the operator of Ascó and Vandellòs II NPPs, for assessing and improving the safety threshold of its plants beyond their design basis, in order to comply with WENRA stress tests specifications concerning External Flooding Events. The analysis begins with the identification of the local environmental factors that can cause a plant flood and all their combinations. Subsequently, the article describes the numerical modeling techniques and the main hypotheses used to represent the consequences caused by a Local Probable Maximum Precipitation (PMP) to Structures, Systems and Components of the Nuclear Plant. The results of the analysis have led to adopting additional measures to increment the Hydraulic Risk safety threshold for the two Spanish Nuclear sites in Catalonia.
A Strategy for Dutch Rivers to Handle Climate Change and New Safety Standards (PAP014351) - Full Paper
Keywords: Flood Management, Flood Risk, Climate Adaptation
Subject: Impact of climate change on flood risk
Abstract:
Water management is crucial to the Netherlands. An advances system of levees, dams and dunes hasbeen constructed over the past centuries to protect its citizens and its economy, making the Dutch Deltathe best protected delta in the world. Programmes like Room for the River and regular maintenanceprogrammes ensure that the current safety levels are maintained. However, to anticipate climate changeand increased economic value behind the levees, it is necessary to consider whether the current safetylevels standards are still adequate for the long term (2050 and beyond). This is done in the DeltaProgramme, a policy project to study new safety standards in combination with expected climate change(and hence, increased discharge and sea level rise) and the appropriated measures to reach to thosestandards.In this paper, we will explain the process of getting to a balanced choice of measures, solving thecombined problem of new standards and climate change. This is not a top-down process, nor bottom up.It is a process which is carried out in a close cooperation with various levels of government andstakeholders. The outcome of the process is a relatively well supported strategy which is however, not ablueprint for 2050, let alone 2100. It gives a direction in which a solution has to be sought, whereas theactual choice of measures (spatial measures, or dike reinforcement) is the subject of the next phase ofthe Delta Programme.
Varieties of Water Level Gauges to Prevent Water-Related Disasters in Japan (PAP014353) - Full Paper
Keywords: Water level gauge, Hydrology observation, Flood forecasting, warning system
Subject: Flood forecasting and early warning systems
Abstract:
In recent years, flood disasters are frequently occurring by typhoons and localized torrential rainfalls, which are heavily damaging people and materials in Japan. Therefore, the importance of water level observation has been re-acknowledged for flood warning and forecasting. Conventionally, water level observation stations have been installed mainly around large rivers which are managed by MLIT (Ministry Land, Infrastructure, Transport and Tourism) and each prefecture. In addition, recently to be prepared for floods caused by localized torrential rainfall, its target is also widening to small or medium rivers which are managed by local government to issue an adequate and prompt flood warning for local narrow area. In these stations, water level gauge is a fundamental equipment and is needed a high accuracy and a high durability. For this purpose, various types of gauges have been developed and improved in Japan.
Monitor Avançado De Enchentes (Maven): a Hydroclimatologic Computational Framework for Early Flood Alert Systems (PAP014354) - Full Paper
Keywords: Decision Support System, Early Flood Alert System, Integrated Modeling
Subject: Flood forecasting and early warning systems
Abstract:
The phenomena associated with water management issues show a level of complexity that requires the knowledge of many experts in addition to the use of modern computational tools, both in what concerns the use of powerful equipment as in the development of integrated and flexible information systems. This work presents the MAVEN system (Monitor AVançado de ENchentes - Advanced Floods Monitor), a computational structure designed and built specifically to monitor hydro-climatological conditions in watersheds, inserting manually or automatically the data monitored in hydrological and hydrodynamics modeling procedures, with the aim of generating values for the water level variation in riparian towns. MAVEN is an application developed for the studied basins. Basically, the operating logic of the system uses a server computer that, running the MAVEN system continually, searches for hydrological current conditions and regional weather forecasting (on Web services and FTP databases), running both automated and manual simulation procedures, for rainfall-runoff transformation integrated with the spread of water level, corresponding to a flood wave along the river. MAVEN provides the results according to four user profiles, associated with their functions within the operating system strategy, these are: the system administrator; the watershed models team; the water administrators; and civil defense officers. The implementation of this system is the result of interagency cooperation (UFPE / SRHE / CPRM) on research in hydrological and hydrodynamics modeling, driven by the Water Resources Group of UFPE, after the 2010 floods in the southern coastal forest of the state of Pernambuco, Brazil. Computational infrastructure and grants were provided by CNPQ, through RedeClima project.
The Analysis of the Rapid Enhancement of "Haikui" (1211) Near Sea Shore and Its Related Heavy Rainfall in Zhejiang Province (PAP014358) - Full Paper
Keywords: Typhoon HaiKui, Rapid Enhancement near sea shore, Cause of Rainstorm
Subject: Flood forecasting and early warning systems
Abstract:
Severe typhoon HAIKUI(1211)generated on August 3, 2012, near centralmaximum wind increased from 35 ms-1 to 48 ms-1, increased 13 ms-1 during the six hours. Thegust with the intensity above 13 grade has been lasting for 26 hours during the period. Themaximum wind is 46.9 ms-1, and 39.4 ms-1 as well as 36.8 ms-1 respectively at Dongji station,and Dachen station as well as Shippu station, which proof the rapid enhancement near seashore. Analysis shows that rapid strengthening of HAIKUI in offshore due to suddenly increaseof lower water vapor and vorticity input, and high-level divergence. The typhoon wassymmetrical at this stage. The lower-level eyewall was small, while stretching out at upperlevel. At the same time, the radial and tangential wind speed was growing with the warm coreexpanding downward. The vertical speed of the vortex was generally small. All changes of thestructures contributed to the maintenance and development of the typhoon. Development ofTC conducive to the energy accumulation near the center, prompting the lower airflowenhancement and carrying rich water vapor transported to eastern Zhejiang coastal, formedthe heavy rain. The evolution of the top level spiral degrees prompting changes of that of thelow and the increase of 850hPa and decreased to zero for the formation and weaken signal ofthe heavy rain about 9 ~ 12 hours before respectively. Horizontal component of Moist PotentialVorticity(MPV) and wet vector can predict the distribution of rain-band before landfall, wetvector can better reflect the range of precipitation after landfall.
Simulation Tools of Flood Risk Management Planning (PAP014362) - Full Paper
Keywords: Flood Risk Management, Flood Risk, HN-Modelling, DTM, GIS
Subject: Flood resilient societies through community preparedness
Abstract:
The Directive 2007/60/EC of the European Parliament and the Council on the assessment and management of flood risks (Flood Risk Management Directive) provides a framework for the mitigation and/or prevention of flood-related detrimental effects on human health, the environment, the cultural heritage and economic activities within the Community. A focus of the analysis in flood risk management plans (FRMPs) lays in the development of flood hazard and flood risk maps. A particular database was developed for the planning of measures which contains a quick and uncomplicated access to all the planned measures for the flood risk management. A key product of FRMPs is the resulting GIS Project which provides an extensive planning tool to describe the flood hazards, to analyse the flood risks and to develop appropriate measures in order to improve the flood risk management in the studied catchment area. This is useful for the continuous updating and completion and forms the basis for the development of the Internet viewer for the Hessian FRMP by the Hessian State Office for Environment and Geology (HLUG). Besides a geographic information system, two-dimensional HN methods, which solve the depth-averaged shallow water equations by means of an unstructured mesh and a cell-centred procedure, are widely used for the named studies. Investigations of flood protection at a section of the Hessian Lahn River, which is an eastern tributary of the Rhine River, will be consulted as the essential sample. In this review the technical and quality requirements are described regarding the digital terrain models and the hydrodynamic-numerical models. The several experiences gathered and tools developed concerning FRM-GIS and two-dimensional modelling are presented in this paper.
Consideration of Costs and Benefits in Flood Risk Management (PAP014363) - Full Paper
Keywords: Flood Risk Management, Flood Risk, Cost-Benefit Analysis, stakeholder involvement, stakeholder training
Subject: Flood resilient societies through community preparedness
Abstract:
The EUs flood risk management directive from 2007 (Directive 2007/60/EC of the European Parliament and of the Council of 23 October 2007 on the assessment and management of flood risks, 6.11.2007 Official Journal of the European Union L 288/27-34) does not require an explicit cost-benefit-analysis (CBA) in flood risk management plans (FRMP).To give an idea about the consideration of effort and gain the FRMP Fulda established in the German Federal State of Hessen is taken as an example. A second example on the use of cost-benefit-analysis (CBA) in European Flood Risk Management is given by the “Flood-CBA”-project. A short introduction to the method of CBA in FRM is followed by the assessment of CBA in Europe and corresponding conclusions.
Application of the European Flooding Directive to Coastal Areas in Spain: Methodology and Tools to Generate Flood Hazard and Risk Maps (PAP014364) - Full Paper
Keywords: Flooding Directive, Flood Hazard, Spanish Coast, Storm Surge, Waves
Subject: Land use and Floods, landslides and erosion
Abstract:
The purpose of the European Flooding Directive (2007/60/CE) is to establish an Europeanframework for the assessment and management of flood risks. The aim is to reduce the adverse floodingconsequences such as human health, environmental and cultural heritage, and economic activity. InSpain, coastal zone flood hazard and risk maps are managed by the Environment Spanish Ministry(MAGRAMA, Dirección General para la Sostenibilidad de la Costa y el Mar). These maps are designedusing the methodology and tools developed by the Environmental Hydraulics Institute (IH Cantabria) fromUniversidad de Cantabria. This methodology allows performing accurate and quick flood hazard mapsalong the Spanish coast, due to the combination of high-resolution marine climate data bases, advancednumerical models, innovative data mining techniques, and statistical models.
Computationally Efficient, Yet Robust, Coastal Flood Risk Analysis Using a Reduced Complexity Inundation Model and Metamodel (PAP014366) - Full Paper
Keywords: Coastal flood risk, Data mining, Multivariate extreme value methods, Surge, Wind-waves
Subject: Floods in a changing climate
Abstract:
To effectively manage coastal flood risk it is necessary to be able to quantify it. This quantification can however, be a challenging undertaking. Coastal flooding risk is defined as the probability of flooding multiplied by the consequences. However, both the probability of flooding and the consequences can vary significantly over broad spatial and temporal scales. The probability component of coastal flood risk it is usually calculated by the application of multivariate extreme value models that extrapolate the joint probability density of the historical data, normally defined by the offshore sea condition (wave height, wave period, wave direction, wind intensity and direction, astronomical tide, storm surge level, mean sea level), to extreme values. Executing the corresponding hydrodynamic and inundation models for the full set of stochastically generated events is often not viable in computational terms. In the study described here, a computationally efficient, and hence practical, coastal flood risk analysis modelling system has been developed. The system applies the multivariate extreme value model of Heffernan and Tawn (2004) to high resolution offshore sea condition data (Camus et al, 2013). The resulting monte-carlo simulation data are then transferred inshore using a meta-modelling approach based on data mining techniques and non-linear interpolation functions (Camus et al 2011). These transformed nearshore data then form the boundary conditions of a reduced complexity (and hence computationally efficient) flood inundation model (RFSM-EDA).The modelling system has been applied to an urban coastal area located at Northern Spain mainly affected by wave-induced overtopping events.
The Delta Programme and Updated Flood Risk Management Policies in the Netherlands (PAP014368) - Full Paper
Author(s): Jos van Alphen
Keywords: flood risk management, climate change, the Netherlands
Subject: Flood risk management in mega cities
Abstract:
The Delta Programme develops strategies that are aimed at protecting the Netherlands against flooding, while anticipating climate change ). The program started in 2010, as a result of the advice of the Dutch Committee on Sustainable Coastal Development (the 2nd Delta Committee) to adapt flood risk management (and fresh water supply) to climate change ). It is aimed at avoiding a disastrous flood, instead of a response after it. Such an anticipatory approach requires a multi-governance organization, integrated strategies dealing with uncertainty and adequate institutional arrangements to guarantee future proof implementation. The multi-governance approach consists of strong involvement of local and regional authorities and stakeholders in strategy development and decision making, within a framework of national coordination. The Delta Programme Commissioner supervises this process, especially regarding progress, coherence between regions, uniformity in methods, models and data. He reports to Parliament every year in September and takes the necessary steps when problems arise. The Delta Programme results in updated standards for flood protection (based on a specified tolerable individual risk), a policy-framework regarding flood-proof urban (re)development and strengthened cooperation with disaster management organisations. Key to the strategies developed is an adaptive approach, in which necessary measures for the short term (maintenance and improvement flood defences and "aging infrastructure"), are framed into the long-term perspective of socio-economic developments and climate change. The multifunctional design of measures is stimulated, since this increases opportunities to combine with other agenda's and enhances societal "added value" (regarding nature, recreation or urban development) and acceptance. Promising examples are elaborated in local and regional workshops. From 2020 onwards, a Delta Fund of about 1 billion euro's per year will provide stability in financial resources, reducing dependency on economic developments and continuous political attention. The new Delta Act forms the legal basis for the implementation of the programme, the responsibilities of the Commissioner and the Delta Fund.
Flood Risk Management With Hec-Wat and the Fra Compute Option (PAP014369) - Full Paper
Keywords: Flood Risk, USACE, HEC, HEC-WAT, Water resources
Subject: Flood resilient societies through community preparedness
Abstract:
The United States Army Corps of Engineers (USACE) has long had policy stating that USACE will analyze its water resources projects, including flood risk management projects, using risk analysis and watershed, systems and life-cycle approaches. However, the software to support these requirements and perform these analyses has not been available. The current software used within USACE to perform flood risk management analysis, HEC-FDA (Flood Damage Reduction Analysis), has a number of limitations that preclude it from readily or intuitively performing a true systems or life-cycle analysis. While HEC-FDA has been the primary flood risk assessment tool for USACE since 1996, it still represents a system of levees as a number of independent project components. For this reason and others, USACE's Hydrologic Engineering Center (CEIWR-HEC) began developing the Watershed Analysis Tool (HEC-WAT). HEC-WAT was initially developed to assist Project Delivery Teams (PDT's) conduct water resources studies of complex riverine systems with an integrated, comprehensive and systems based approach. However, since USACE also requires a life-cycle analysis, it became clear HEC-WAT needed additional capability that would allow a risk analysis to be performed while also incorporating a life-cycle approach. Therefore, the research and development scope grew as it became clear that USACE current tools and practices were still not able to address all USACE needs. Thus, HEC-WAT took on a more complex nature and the Flood Risk Analysis (FRA) compute option was added. This new capability allows HEC-WAT to run a Monte Carlo analysis so a robust risk analysis can be performed throughout the life-cycle. HEC-WAT/FRA includes systems and life-cycle approaches, event-based sampling, parameter sampling, and the ability to do scenario and alternative analyses. Applications of the FRA compute include levee certification studies, dam and levee safety studies, and planning and design studies. It will also advance USACE modeling approaches for flood risk analysis. An initial implementation of HEC-WAT/FRA has been constructed for the Columbia River Treaty (CRT) 2014/2024 Review project. The purpose of the CRT, which became effective in 1964, is to provide flood control and power benefits to the United States and Canada. The goal of the CRT Review is to provide United States decision makers with the necessary information to support a decision regarding the future of the CRT with Canada. While the Treaty has no expiration date, it can be terminated by either party in 2024, provided the other party has been given a ten year advance notice. CEIWR-HEC is a member of the PDT that is undertaking a series of studies to collect critical information needed to support the possible renegotiation of the CRT. This paper will describe the HEC-WAT/FRA and how it will be used to assess current treaty operations and possible future treaty alternatives. This presentation will also describe the scientific advancements included within HEC-WAT/FRA, how it was used to for the CRT study and how it will advance USACE modeling approaches for flood risk analysis.
Interagency Teaming in Flood Risk Management - Silver Jackets (PAP014370) - Full Paper
Keywords: Flood Management, Silver Jackets, Interagency Collaboration, Leveraging
Subject: Flood resilient societies through community preparedness
Abstract:
The Silver Jackets is an innovative program that continuously brings together multiple Federal, State and sometimes local, Tribal and non-governmental representatives to learn from one another and apply their knowledge collaboratively to reduce the risk of flooding and other natural disasters, and to enhance response and recovery efforts when such events do occur. No single government agency has all the answers, but often multiple programs can be leveraged to provide a sustainable solution. Silver Jackets provides a formal and consistent strategy for an interagency approach to planning and implementing measures to manage the risks associated with flooding and other natural hazards. Although each state-led team is unique, common participants include state agencies with mission areas of hazard mitigation, emergency management, floodplain management and natural resources management and conservation. Federal participation typically includes the US Army Corps of Engineers (USACE), the Federal Emergency Management Agency (FEMA), and often includes the National Weather Service (NWS), National Oceanic and Atmospheric Administration (NOAA), the US Geologic Survey (USGS), the Natural Resources Conservation Service (NRCS), and the Environmental Protection Agency (EPA). Silver Jackets teams are developed at the state level with support from USACE, FEMA and additional Federal agencies. Teams focus on the flood or all-hazard risk management priorities of their individual states, building a life-cycle strategy to build resiliency in the state. Through the USACE representative on the state team, USACE supports team collaboration to achieve multiple goals, including: 1) leveraging resources, authorities and programs and applying them in a coordinated manner among agencies, 2) sharing data and information, 3) reducing duplication, 4) identifying gaps and barriers to implementation, and applying solutions or providing recommendations to overcome them, 5) providing multi-agency technical resources to assist state and local agencies,6) increasing and improving flood risk communication through a unified interagency effort, and 7) establishing ongoing relationships to facilitate integrated post-disaster solutions after a disaster. Currently, 40 states are served by active teams, and efforts to offer a team to the remaining 10 states continue. Over the last three years, Silver Jackets teams have initated sixty (60) pilot projects, leveraging $5.7 million in USACE investment against a $5.0 million investment from state, local, federal and other agencies. Forty-one projects in twenty-five states focus on either flood risk management or levee safety issues. Nineteen projects in nineteen states will achieve nonstructural objectives. In tracking the benefits of these projects, teams focus on assessing risk; raising awareness; promoting action at multiple levels; and quantifying how risk was reduced or managed. This presentation will provide an update on the progress of state-led Silver Jackets teams, from initiation through a variety of activities throughout the risk management life-cycle, to completion of collaborative projects and coordinated response and recovery actions.
Calculation of Flood Losses in the United States (PAP014374) - Full Paper
Keywords: Flood Risk Management, Flood Damages, Federal Government
Subject: Floods in a changing climate
Abstract:
In the United States, no one Federal agency has the responsibility for managing flood risk. One important implication of this is that no one agency collects data on damages and losses caused by flood events. Rather, many agencies collect different types of data and make use of such data in different ways in order to meet their individual missions and purposes. This does not necessarily result in a complete understanding of flood damages and losses experienced due to flood events within the Federal government. Further, it is not necessarily an efficient process, and may result in both duplication of effort in collecting data and gaps in the data that is collected. The Federal Interagency Floodplain Management Task Force (FIFM-TF), an interagency group representing ten Federal agencies with missions and authorities related to flood risk and floodplain management, recognized the limitations caused by this piecemeal approach, in terms of both lack of efficiency within the Federal government and lack of complete understanding of the flood problem within the country. To better understand this problem, the FIFM-TF convened an interagency meeting of experts involved in their agencies' efforts to collect flood damage and loss data. The purpose of this meeting was to discuss what types of data were collected by each agency and how each agency used their data. Through this discussion, potential efficiencies in data collection efforts between agencies were identified, as were gaps in the types of data that were collected and used within the Federal government. The discussions, challenges and solutions identified, and improvements resulting from this interagency meeting will be discussed in detail. Further, longer term discussion on how the Federal government might lead efforts to develop a more accurate and comprehensive estimate of flood damages and losses to the Nation will be provided, including recommendations under consideration by the FIFM-TF for moving forward with such an activity.
Effectiveness of Federal Floodplain Management in the United States - Executive Order 11988 (PAP014375) - Full Paper
Keywords: Flood Risk Management, Executive Order 11988, Federal Policy
Subject: Flood resilient societies through community preparedness
Abstract:
In the United States Federal floodplain management is guided by Executive Order 11988 (E.O. 11988), which was issued in 1977. E.O 11988 directs Federal leadership to “take action to reduce the risk of flood loss, to minimize the impact of floods on human safety, health and welfare, and to restore and preserve the natural and beneficial values served by floodplains.” These factors were intended to be considered whenever the Federal government carried out its’ responsibilities for acquiring, managing, and disposing of Federal lands and facilities, providing Federally undertaken, financed, or assisted construction and improvements, and conducting Federal activities and programs affecting land use, including but not limited to water and related land resources planning, regulating, and licensing activities. The intent of E.O. 11988 was not to strictly prohibit all Federal activity or support for activity occurring within or impacting floodplains, but rather to ensure that the effects of those activities were considered and understood, and that all practicable steps possible were taken to minimize adverse effects of those actions which must occur within or impact a floodplain. Recently, the Federal Interagency Floodplain Management Task Force (FIFM-TF), an interagency group representing ten Federal agencies with missions and authorities related to flood risk and floodplain management, investigated the implementation and overall effectiveness of E.O. 11988. The FIFM-TF designed a survey to be completed by representatives of each Federal agency with implementing requirements under E.O. 11988. This survey was designed to provide improved understanding of the effectiveness of E.O. 11988 itself and of individual agencies’ implementation of EO 11988. This paper will discuss what the Federal agencies expect to learn from the survey and next steps for improving Federal guidance on flood risk management in the United States.
Us Army Corps of Engineers North Atlantic Coast Comprehensive Study (PAP014376) - Full Paper
Keywords: Sandy, Coastal Storm Risk Management, Climate Change
Subject: Flood resilient societies through community preparedness
Abstract:
The United States is experiencing a trend toward increased frequency, high magnitude storm events such as Hurricanes Katrina and Rita in 2005, and storms of large areal extent creating larger damage areas as evidenced by the size of Hurricane Irene in 2011and Hurricane Sandy in 2012, Given the reality of sea level rise as a probable future condition, the Disaster Relief Appropriation Act of 2013 (P.L. 113-2) recognized the need to comprehensively evaluate the existing and planned measures to reduce the flooding risk from tidally-influenced storm surges as well as other alternatives for areas at risk to future storm damages. The legislation directed the US Army Corps of Engineers (USACE) to undertake a Comprehensive Study of the Sandy impacted areas in the North Atlantic Division (Maine to Virginia) to be conducted in coordination with other Federal agencies, and State, Local, and Tribal officials to ensure consistency with other recovery plans being developed. The goals of the North Atlantic Coast Comprehensive Study are to (1) provide risk reduction strategies to reduce risk to which vulnerable coastal populations are subject, and (2) support coastal resilient communities and sustainable coastal landscape systems, considering future sea level rise and climate change scenarios, to reduce risk to vulnerable population, property, ecosystems, and infrastructure. The Comprehensive Study will include a coastal framework as well as storm suite modeling, coastal GIS analysis, and related evaluations, for the affected coastlines. The study will identify existing nature systems and nature-based features, such as ecosystem restoration projects, and describe their contribution to regional resiliency during Hurricane Sandy. Methodologies for evaluating the resiliency benefits that nature-based features may contribute in conjunction with other types of risk reduction measures (structural and non-structures) are being advanced as part of the Study. The Comprehensive Study is being developed by a USACE enterprise team working collaboratively with subject matter experts from other Federal Agencies, Regional Partners, Academia, and Non-Governmental Organizations. This team is being led by the USACE Coastal Storm Damage Reduction Planning Center of Expertise and the USACE Team members are coastal scientists, planners and engineers drawn from North Atlantic Division districts, the National Coastal Working Group, the USACE Engineer Research and Development Center, and the USACE Institute for Water Resources, incorporating other USACE resources and expertise as appropriate. This paper will describe the current status of the Comprehensive Study, ongoing collaborations, technical products, and way ahead leading to the January 2015 submission to Congress.
Using Hec-Fia to Identify the Consequences of Flood Events (PAP014378) - Full Paper
Keywords: Consequences, USACE, HEC, HEC-FIA, Uncertainty
Subject: Flood risk management in mega cities
Abstract:
As the world's population grows the need for development increases; this need for additional space causes land use decisions to be made that can increase flood risk. This pressure to expand creates many changes in our floodplains that significantly increase the exposure of the public and the overall economy of a region to flood hazards. Urban sprawl not only increases the number of structures and thus value exposed in the floodplain, it also increases the population exposed within the floodplain. Additionally, the urbanization of regions increases the rainfall runoff relationship thus increasing flood risk from a hydrologic perspective, and can limit the feasibility of structural flood risk mitigation measures. All of these simultaneous changes in the floodplain can create significant risk for the future. To evaluate the consequence portion of the risk equation, the United States Army Corps of Engineers' Hydrologic Engineering Center developed the HEC-FIA (Flood Impact Analysis) software, HEC-FIA is used to estimate current and future floodplain consequences with uncertainty. By estimating the consequences, the benefits of existing and future flood risk management measures can be evaluated and compared. HEC-FIA utilizes geospatial datasets to build structure inventories and then assigns values and population per structure. Using this information and geospatially derived flood depth grids (provided by a piece of hydraulic software), HEC-FIA estimates direct economic, indirect economic, agricultural, and life loss consequences for flood hazards. HEC-FIA can compute results for a single event in either deterministic mode or in uncertainty mode which utilizes a Monte Carlo approach. The user can define the uncertainties about any structure in the floodplain in many ways, and each has various impacts on the different consequence calculations. For example, foundation heights, structure values, and depth damage relationships impact economic consequences, while foundation heights, warning issuance times, and fatality rates all can be defined with uncertainty to impact the life loss calculations. HEC-FIA can also be linked into HEC-WAT (Watershed Analysis Tool) with the FRA (Flood Risk Analysis) compute option to randomize the events being evaluated in HEC-FIA so that hydrologic, hydraulic, geotechnical, and economic uncertainties can all be represented and evaluated by alternative within the floodplain. This capability allows users to evaluate current and future risk in a changing environment. This paper will describe how HEC-FIA can be utilized to help evaluate the consequences for various alternatives within a floodplain.
Efforts by the U.S. Army Corps of Engineers (Usace) to Characterize National Flood Risk (PAP014379) - Full Paper
Keywords: Flood Management, Flood Risk, Risk Characterization, Risk Classification
Subject: Land use and Floods, landslides and erosion
Abstract:
The U.S. Army Corps of Engineers (USACE) is investigating ways to characterize the nation's flood risks in order to highlight priority areas nationally and regionally and to identify effective approaches to manage the nation's flood risk, both internally and in partnership with others. Specifically, USACE is developing tools to integrate and display components of flood risk from a variety of sources, identify its contributions to flood risk reduction, frame its projects within a broader and watershed-based context, and identify potential areas of concern in the future. Flood risk components address the flood hazard (e.g., extent of flood hazard as shown on digital Flood Insurance Rate Maps, approximate extent of flood hazard for specific probability floods determined via nationwide estimation algorithms, approximate extent of projected future flood hazards for specific probability floods, number of historical Federally-declared flood disasters) and exposure and vulnerability to that hazard (e.g., population, number and type of buildings, value of buildings, critical infrastructure, projected population growth, repetitive loss flood insurance claims density, demographic social vulnerability). Geospatial and assessment tools allow quick visualization of the relative scale of each component or a combination of components, providing a general sense through varying perspectives of national and regional flood risk; allowing comparisons to national or regional norms; enabling summation of varying exposures for watersheds, political jurisdictions, and nationally; and highlighting potential opportunities for flood risk reduction. Continued development and coordination is anticipated to refine the tools and make them and their results more widely available.
The Methodologies for the Flood Control Planning Using Hydropower Reservoirs in Brazil (PAP014381) - Full Paper
Keywords: Planning, Flood Control, Controllability Conditions, Multiple uses
Subject: Floods in a changing climate
Abstract:
The continental dimension of Brazil, including basins with large hydropower potential tookthe option of an electrical matrix predominantly hydroelectric (approximately 70% of the Brazilian matrix).One of the particularities of the Interconnected Brazilian Hydrothermal System operation planning is theneed of using part of the volumes of the hydroelectric plants reservoirs as waiting volumes for attenuationof possible floods, avoiding damages to hydro plant’s downstream areas. The consideration of floodcontrol in the reservoirs of hydropower plants is both an opportunity and a challenge, since the two usesof water (hydropower generation and flood control) are conflicting. While the first aims to keep thereservoirs filled at the end of the rainy season to use the water stored during the dry season, the floodcontrol aims to keep the reservoirs empty to store the volume of large floods that may occur during therainy season to avoid damage in downstream areas. To minimize this conflict, Brazil has been developingmethodologies and computational tools for planning reservoir operation considering power generationand flood control. This paper focus on the methodologies and computational tools for planning the floodcontrol operation in the Brazilian power system reservoirs addressing the methodology adopted tocalculate the "Waiting Volumes". An application of the methodology and the computational tools will bepresented, using as a case-example the Paraná River basin, located in the southeastern region of Brazil.
The Operation of Flood Control in Large Hydroelectric Power Systems - the Brazilian Experience (PAP014382) - Full Paper
Keywords: Flood Control, Flood Prevention, Operation, Multiple uses
Subject: Floods in a changing climate
Abstract:
This paper presents a Brazilian’s Interconnected Power System real flood attenuationexperience during the second biggest flood at the Parana River basin, in the southeast of Brazil, fromNovember 2006 to April 2007. It will be presented the decision making process regarding the planning,programing and operation levels and the support provided for the flood attenuation set of models. It willalso show the institutional articulation involving the BIPS’s agents and, mainly, the National Water Agency(ANA).
Development of Flood Risk Assessment Method for Data-Poor River Basins: a Case Study in the Pampanga River Basin, Philippines (PAP014383) - Full Paper
Keywords: Flood Risk Assessment, Hazards, Exposure, Vulnerability, Damage Function
Subject: Impact of climate change on flood risk
Abstract:
In recent years, floods frequently occur in the world, which cause serious damage of properties and loss of lives. An assessment of flood risk in the river basin is thus very important for development activities and river basin management. In this study, the flood damage assessment method was developed for the assessment of flood risk in data-poor river basins by using physical based numerical model, satellite-based information and socio-economic factors. The Pampanga river basin of the Philippines was selected for the case study. For the flood damage assessment, the hazard characteristics such as flood depth and duration were computed by using Rainfall Runoff Inundation (RRI) model. Agriculture and household which are major exposures in the flood prone areas were taken into account for the flood damage assessment. The potential damages of agriculture were estimated by using the damage function of agriculture and flood characteristics. The damage functions of agriculture for its each growing stages were defined as the function of flood depth and duration. Field investigation and questionnaire surveys were conducted at the selected Barangays (Villages) in the Pampanga river basin to develop methodology for household damage estimation. The appropriate damage functions for household building and assets damages were developed based on the flood and household characteristics. The estimated damages of agriculture and household were consistent with the reported values. The developed method can be applied in other river basins where damages data are poorly available.
Parameter Estimation and Uncertainty Analysis of the Variable Infiltration Capacity Model in the Xitiaoxi Catchment (PAP014384) - Full Paper
Author(s): Bo Pang and Lanying Zhang
Keywords: VIC model, GLUE, Parameter Estimation, Uncertainty Analysis
Subject: Flood forecasting and early warning systems
Abstract:
The Xitiaoxi catchment is one of the most important catchments of Tai lake basin. Thefrequent flood disasters have been the most serious problems in Tai lake basin due to increasingdrowned areas and economic loss. In this research, VIC (Variable Infiltration Capacity) model was appliedto Xitiaoxi catchment for better understanding of the flood generation process over the Tai lake basin.GLUE (Generalized Likelihood Uncertainty Estimation) method was selected to address VIC modelparameter estimation and uncertainty analysis, and its contribution on model simulation uncertainties. Theresults indicates that: (1) VIC model performs satisfactorily in daily discharge simulation of the Xitiaoxicatchment; (2) In the seven selected parameters, the variable infiltration curve parameter B and soil depthof the first soil layer d1 were more sensitive than others; (3) Contributions of parameter uncertainty onmodel simulation uncertainties are relatively high.
Flood Risk Assessment of Climate Change Impacts Using a Detailed 1d/2d Coupled Model. Application to Barcelona Case Study (PAP014387) - Full Paper
Keywords: Flood risk, Climate change, 1D/2D Coupled Model
Subject: Impact of climate change on flood risk
Abstract:
In a context of high uncertainty about hydro-climatic variables, the development of updatedmethods to assess climate change impacts, is as important, if not more important, than the provision ofimproved climate change data. This paper shows the results achieved in the Barcelona case study in twointerdisciplinary projects funded by the European Commission in the framework of the 7th FP (CORFUand PREPARED projects). A detailed 1D/2D coupled model, simulating surface and sewer flows wasdeveloped for the Barcelona case study using Infoworks ICM version 3.5 by Innovyze. Special attentionwas paid to the hydraulic characterization of the inlet systems (representing the interface between surfaceand underground flows) using experimental expressions. The 2D domain covers 44 km2 of the city landinvolving 235 km of sewers, while 2D mesh counts more than 400,000 cells. Sewer and overland flowmodelling was calibrated and validated using data regarding 4 critical rainfall events occurred in 2011.Modelling speeding-up strategies focused on parallel processing, hardware advances and a specific codebased on fast graphic processing units (GPU), allow to obtain simulation results of the developed modelwith very short computational times (3-4 minutes). In this context, real time strategies and early warningsystems could be activated on the basis of the result of the developed coupled model. Once the coupledmodel was calibrated, it was used to assess the flood risk in the Raval District, (historically affected byflooding problems during heavy storms) for current and future scenarios. For the future scenarios, climatechange inputs were defined. Specifically, in order to quantify the impacts of climate changes on the RavalDistrict for the horizon 2050, 4 CO2 emission scenarios (A1B, A2, B1 and B2) were considered and a searise of 0.20 m were considered.
Identification for the Impact of Climate Change and Human Activities on Streamflow in Xitiaoxi River Basin, China (PAP014388) - Full Paper
Keywords: climate change, human activities, Change-point, Taihu Lake
Subject: Impact of climate change on flood risk
Abstract:
As the crucial headwaters of Taihu Lake basin, Xitiaoxi River basin was chosen as the study case. Under the significance level 5%, Mann-Kendall, Pettitt, Moving T test, Yamamoto and the residual mass curve combined rank test methods were applied to comparative analyze the change-point of precipitation and streamflow from 1972 to 2010 in the basin. It found that the change-point of precipitation and streamflow time series both happened at the year 1999 in the basin. Two approaches (double mass curve and hydrological sensitivity-based methods) were used to quantitatively identify the impact of climate change and human activities on streamflow based on abrupt change analysis. The results obtained by using two approaches were verified each other, and it showed that the factors of climate change attribute to 21%~28% and human activities 72%~79% of total impact. Human activities attribution is dominant and it is the most considerable cause for the variation of hydrological processes in the basin.
Best Management Practices as Alternative for Flood and Urban Stormwater Control in a Changing Climate (PAP014390) - Full Paper
Keywords: climate change, extreme rainfall, urban drainage, best management practices
Subject: Floods in a changing climate
Abstract:
Global climate models regarding the predicted scenarios of Greenhouse Gases (GHG) emissions, forecast a general increase in intensity and frequency of extreme rainfalls. Advanced studies in regional and local scales attest this intensification with greater spatial and temporal precision. The increase in rainfall associated with urban growth and more impervious surfaces, will lead to unprecedented impacts on drainage infrastructures, with high risks of flooding. Projections by the National Institute for Space Research (INPE) for Greater São Paulo, which already suffers from severe floods every summer, indicate a likely increase in the number of days with heavy rainfall until the end of the century. INPE also estimates that, between 2070 and 2100, a regional rise in temperature of 2 ° C to 3 ° C could double the number of days with heavy rainfall (over 10 mm) in the city of São Paulo and its metropolitan area. Considering the current scenario of urban sprawl and heavy rains, which both tend to worsen imminently, conventional solutions for stormwater management are still the dominant model in São Paulo and in Brazilian cities. Public administrators, policymakers, contractors and professionals - Engineers, Planners and Landscape Architects - still rely on stormwater detention and usual solutions for drainage infrastructures as the only suitable alternative, even with its growing costs and evident inefficiency in water conservation. In fact, detention ponds, known locally as "big pools", were found to be very successful to prevent floods in the Greater São Paulo, and thus to mitigate material loss of population, traffic and other issues related to the limited conveyance of water in urban streams. However, when considering the hydrological cycle and natural processes, not to mention urban and social impacts, this strategy has proven to be ineffective. The immediate problem is solved in terms of hydraulics, but with the floods, pollution throughout the watershed is drained into detention ponds, which hold not only the surplus water, but trash and siltation. Then, numerous drawbacks become frequent for the operation and maintenance of these facilities, such as obstructions, unpleasant odor and unattractive landscape, which often result in rejection by the surrounding neighborhood. Facing the need of adaption to the future scenario, cities have the opportunity to perform an infrastructural transition when adopting stormwater Best Management Practices (BMPs) as a sustainable, resilient and landscape friendly solution. This paper presents a qualitative and quantitative comparison between BMPs techniques and usual detention reservoirs as flow control strategies. Regarding a case study urban watershed in Greater São Paulo, where two reservoirs with total volume of 19.200m3 were built, porous sidewalks and bioretention elements have been located in the contribution area within this basin. The retention volume of these proposed techniques considering their average porosity corresponds to 42% of the reservoirs capacity. It is then confirmed the stormwater BMPs viability and suitability as alternatives to adapting cities to climate change, but their efficiency relies on a design that takes into account the specific local environment.
Flood Hazard Assessment Approaches for Climate Change (PAP014391) - Full Paper
Keywords: Flood Flow Estimates, Climate Change Impacts, Flood Management
Subject: Impact of climate change on flood risk
Abstract:
This paper discusses different flood hazard assessment approaches to account for climate change in Western Canada. Three recent flood hazard assessment studies in British Columbia that accounted for climate change are presented. The study areas are quite different in terms of population, geophysical conditions and spatial extent, and each area will need to confront distinct flood hazards and flood management challenges. However, similarities also exist. The first study describes the Lower Mainland experience centered on the City of Vancouver on the south coast. With sea levels expected to rise by as much as 1 metre or more over the current century, increased flooding in the Vancouver area will primarily be a function of rising seas, increased storminess and coastal erosion. Rainfall, which is concentrated in winter, and is expected to become more intense, would challenge current drainage systems. The combination of increased river flows and rising sea levels will exacerbate flooding in coastal areas. The second case study is for City of Prince George, in the geographical center of the province. Flooding in the Prince George area occurs both in the early summer during snowmelt and during late fall or early winter during river freeze up. An understanding of the flood mechanisms is required to assess how the anticipated changes in temperature and precipitation may affect future flood hazards. The third example evaluates flooding at small aboriginal communities in the Coastal Mountains along the Lillooet River. The Lillooet River has seen unusually large peak-flow increases over the past several decades and an adequate future degree of flood protection must be determined for these isolated communities. Flood hazard assessment approaches for each of the three regions, and how they can incorporate the specific climate changes (including marine climate) that are projected for each region, will be reviewed. Recommendations for adaptive actions will be presented for each region. The flood hazard assessment approaches discussed in this paper are believed to be applicable to a number of locations.
Building Local Capacity for Managing Natural Disaster in Chile. the Experience of the Coastal City of Talcahuano (PAP014395) - Full Paper
Author(s): Alejandro Lara
Keywords: Flood Management, governance, prepared communities, public participation, social learning
Subject: Flood resilient societies through community preparedness
Abstract:
After the February 27th 8.8º earthquake (Richter scale) that affected the center-south of Chile and originated the tsunami which flooded a big percentage of the residence area and military base of the Talcahuano city, and affected a population higher than 180.000 people, (including 23 casualties and invaluable economic and environmental losses). We developed a social perception study to know what the people that was affected by the earthquake-tsunami felt, about risk, vulnerability, copy capacity concepts and how their assessment the local capacity for managing natural disaster. This diagnostic was not encouraging to the decisions taken because local population felt unsaved of flood episode, they were living with fear, gave a low score to the local government capacity to management natural disasters, and they did not fell involved in the reconstruction process and local planning. Considering this scenario, three years later of 27F, the harbor city of Talcahuano has been implemented, a new strategy with the goal to change the way to manage the risk and reduce natural disasters. This research based in the approach of governance reform risk, analyzed and evaluated the local public police implemented, and focused its results to answer three questions: a) how a flood risk could become a opportunity; b) how the governance process actions allow to involve and include the citizen in flood risk management strategy, especially in the basic principle of pro action and prevention, and c) which is the new step.
Local Flood Control Plan in Beijing Central Area (PAP014397) - Full Paper
Author(s): Xiaoxin Zhang
Keywords: Local flooding, Causes analysis, Strategy
Subject: Flood risk management in mega cities
Abstract:
In recent years, local flooding has occurred several times in Beijing. This paper take the July 21, 2012 heavy rain occurred in Beijing as an example, summarize the city drainage system planning and implementation in center of Beijing, analyze the main causes of Beijing local flooding. This paper propose perfect local flooding control planning and design standards, improve the urban drainage system construction projects, establish stormwater control systems relative regulations, strengthen urban flood emergency management planning measures, and provide decision support for urban planning and construction of flood control and drainage emergency management.
The Complicity of Urban Planning in Building Territories at Risk: the Case of the Urban Flooding in the Harbor-City of Talcahuano (PAP014399) - Full Paper
Keywords: Urban Planning, Flood Risk, land use, social effects, economic effects
Subject: Urban Floods
Abstract:
The earthquake and tsunami in Chile in 2010, served to highlight the situationaround the country about how disasters and human settlements are managed. This researchfocuses on identifying the main social, economic and environmental effects of urban planningprocesses, implemented in Talcahuano between 1990 and 2010, were generated in the territoryand how these are linked to the risk of flooding. For this, we used a mixed methodologicalapproach, which involves observing the existing risk and hazard mapping, documentaryanalysis of planning instruments and prevailing legislation, and; the design of an index of social,economic and environmental effects that allows their hierarchical organization.The main results establish that the urban planning processes carried out in the port city ofTalcahuano, between 1990 and 2010, contributed to the exposure of different communities tothe risk of flooding. This, by the repeated changes in land use plans and the dysfunctionality ofthe decisions concerning to the local administration and the central government of the country.Also displayed, even the communal economy has been boosted through various land useplanning processes, loss of flora and fauna is evident in the territory.
The Assessment of Flood Alleviation Benefit of Land Use Management (PAP014400) - Full Paper
Keywords: Flood management, Risk analysis, Land use, Benefit assessment
Subject: Land use and Floods, landslides and erosion
Abstract:
Affected by rapid urbanization and the global warming, the features of flood have been and will be changed significantly in China. Land use risk management is an important measure to restrain the growing flood risk. Taking Taihu Basin as an example, a flood management benefit assessment model has been established. The future flood risk, the benefit of land use risk management and the integrated flood management measures are evaluated. The results reveal that by 2050 the flood risk of Taihu Basin will increase by 4~15 times under different climate change and socioeconomic scenario. The land use management will decrease the future flood risk by 39~50%, while the integrated measures may decrease the future flood risk by 70~74%. Based on the results, some suggestions are made for adjusting the strategic planning of flood management in the Taihu Basin.
Flash Flood Early Warning Indicators for South Branch of Censhui Watershed (PAP014403) - Full Paper
Keywords: Small Watershed, Flash Flood Early Warning, Early Warning Indicators, Hydrological Modeling, Critical rainfall
Subject: Flood forecasting and early warning systems
Abstract:
Using hydrological modeling technique with detailed sub-basin delineation, this study introduces basic concept and methods of analyzing warning indicators for flash flood early warning. Taking South Branch of Censhui watershed in China as an example, 3 typical early warning indicators for flash flood dynamic early warning were investigated. The primary indicator, critical rainfall, was analyzed at 3 early warning stations located inside the watershed, and other two important indicators, warning discharge threshold and warning rainfall duration, were also estimated using the results of critical rainfall. This research illustrates that detailed watershed characteristics can be modeled in-depth by further delineate the watershed into smaller sub-basins to simulate spatial distribution of various basin parameters. The resulted runoff and flood hydrographs show better accuracy at all 3 early warning stations. It further confirms that time of concentration of a watershed is an important factor to warning rainfall duration, and the antecedent soil moisture condition of the watershed has significant impact to the critical rainfall.
Method for Developing Hazard Map Due to Debris Flow Prediction (PAP014408) - Full Paper
Keywords: Debris flow, 1-D numerical simulation, 2-D numerical simulation, hazard map
Subject: Land use and Floods, landslides and erosion
Abstract:
This study aims to propose a method for developing hazard maps due to debris flow based on numerical simulations with 1-D and 2-D debris flow models. The 1-D numerical simulations were conducted to investigate variables responsible to debris flow volume. 2-D numerical simulations were performed to analyze the debris flow behavior over ideal debris fans, as well as to obtain basic information necessary for preparing a hazard map. The 1-D numerical results show that the debris flow volume increases with supply water discharge, length of stream reach and bed slope in condition that potential erosion depth is large enough for sediment transport capacity of debris flow, and that the debris flow size reaches its equilibrium after flowing over some distance. The 2-D numerical results show that debris flow spreading increases longitudinally with the fan slope and in addition, a hazardous area, which is usually considered as deposition area, is reproduced in response to the ground surface topography of the fan, although there is an artificial channel for draining flood water.
Assessment of Rainfall-Runoff Models for Flood River Extreme Event Simulations (PAP014409) - Full Paper
Keywords: Rainfall-Runoff Models, Extreme Events, Una River
Subject: Flood forecasting and early warning systems
Abstract:
Floods are characterized by a rapid runoff response to the rainfall. In many cases, due tothe fast response time, it is difficult to provide alerts and to establish the actions needed to remove thepopulation from risk sites. The objective of this study is to analyze the performance of three hydrologicalmodels, HEC-HMS (Hydrologic Engineering Center - Hydrologic Modeling System), MGB-IPH model(Large Basins Hydrological Model) and MODAHC (the acronym from Portuguese “Self CalibratedHydrological Model”) in order to determine which model has the best performance in the simulation of theextreme flood events in the Una River basin in the State of Pernambuco. The analysis will help choosingthe hydrological model more adequate to be used in the operation of a flood warning system in the State.The selection of the hydrological models pursuit to take into account the distinct characteristics and thedifferent ways of parameterization. This will provide an accurate analysis of the extreme events simulationperformance. MODHAC is a rainfall-runoff lumped model. The HEC-HMS is distributed by sub-basinsdeveloped in HEC-USACE. The MGB-IPH is distributed by cell and it has been widely applied in largebasins in Brazil. The simulations have been accomplished at five streamgauges for extreme eventsoccurred in 2000, 2004 and 2005. The models analysis were performed using graphs and statisticalcriteria such as relative peak discharge error, volume error, standard deviation, mean absolute error, rootmean square error, Nash-Sutcliffe coefficient and coefficient of determination. MODHAC had moredifficulty to represent the streamflow in the study area, hence the MGB-IPH and HEC-HMS achievedgood results and similar performance. One factor in favor of the HEC-HMS model is the facility ofimplementation and integration with the hydrodynamic model HEC-RAS.
Development of a Flood Forecasting System on Upper Indus Catchment Using Ifas (PAP014410) - Full Paper
Keywords: hydrological modeling, large river basin, Indus, IFAS, GSMaP-NRT
Subject: Flood forecasting and early warning systems
Abstract:
A flood forecasting system based on hydrological modeling is already covering main Indus but the upperreaches and Kabul river basin where most of the 2010 flood victims were located are not. This is thetarget for this research, providing a calibrated hydrological model to be the base of a flood forecastingmodel for Upper Indus river basin. Upper Indus river basin up to Taunsa, covering 577,000 km2 has beenmodeled with IFAS (Integrated Flood Analysis System) based on a 5 km gridded, spatially distributed 3layered tank model. The model building was performed in order to account as much as possible for localdata available. In particular, soil hydraulic data newly surveyed by Pakistan Council of Research in WaterResources have been integrated in this model. However, a part from the great area to be covered, thelack of sufficient local hydrometeorological data had also to be overcome. Indeed for the upper reaches ofthe basin, there are only 24 rain gauges covering 133,300km2 and only nine discharges measurementspoints at river stations, barrages and dams are available along the 1,650 km of Upper and Mid Indus. Themodel was calibrated on three flood events including 2010 floods and validated on three other eventsincluding 2012 recent floods. The simulation results suggested the uncertainty of rainfall data was great.For this reason, upstream discharges were input as boundary conditions and as a result, Nash-Sutcliffefficiencies reached a satisfactory average. Moreover, as an alternative to raingauges data, GSMaP-NRT(Global Satellite Mapping of Precipitation, Near-Real Time product) was calibrated and considered inrunoff analysis. Input rainfall slightly improved but not enough to explain all runoff and therefore, in orderto achieve acceptable performance, it is recommended to rely on upstream discharges as boundaryconditions.
The Potential Distribution and Risk of Flood Waterlog on Cropland in the Middle-Lower Reach of Yangtze River in China (PAP014411) - Full Paper
Author(s): Youhao E, Zhiguo Huo and FEI MAO
Keywords: Flood waterlog, Cropland, Rainstorm, Yangtze River, China
Subject: Land use and Floods, landslides and erosion
Abstract:
The floods waterlog on crop and farmland induced by heavy rainfall is one of the primarynatural disasters and has resulted in large number of food losses across the world. Flood submerge cropsin whole plants or part of the plants for long time, leading to the insufficiencies of oxygen in plant roots andlodging, resulting in decrease in production. In China, the average 9.42×106 ha of croplands were sufferedby flood waterlog every year with more than 1000 tons loss of food, while more than 55% of them occurredin the middle-lower reach of Yangtze River. With the increase in extreme rainfall events in future’s climatechange, it is very important to map the potential risk areas of flood waterlog induces by heavy rainfall toselect the flood resistant cultivars and manage the farmlands. In this paper, based on the data sets from 74meteorological stations in southeastern China during the periods of 1961 to 2008, the times of day of heavyrainfall that the daily precipitation were more than 50 mm, the largest daily precipitation of every stations,the largest continual precipitation of every stations and the probable distribution region of a heavy rainfallprocess were statistically analyzed and mapped by the GIS methods. And then, the fine resolution DEMextracted from the Yangtze River watershed and the vector land use map were add to analyze the potentialsinking areas using the Hydrology Model according to different probabilities of heavy rainfall (P = 1%, 2%and 10%). The results showed that the times of rainstorm and the largest daily precipitation, the largestcontinual precipitation and the spatial distribution of a rainstorm process distributed in the middle-lowerreach of Yangtze River with the distribution center area from Wuhan to Jiujiang. The potential risk croplandareas suffering severe and moderate flooding waterlog would be 650 (P=1%), 430 (P=2%), and 270(P=10%) ×104 ha respectively, approximately accounting for 28, 18 and 11% of the cropland areas in studyarea. The severe, moderate and slight flood waterlog area would be submerged cropland in 1.5 to 3.5 m,1.0 to 2.5 m and 0.5 to 1.5 m respectively.
Flood Mapping in Urban Area Using Hec-Ras Model Supported by Gis (PAP014412) - Full Paper
Keywords: Flood mapping, GIS, HEC-RAS, Cedros River
Subject: Urban Floods
Abstract:
Floods are among the most damaging natural disasters in Brazil, not only financially, but also in human terms. In 2011, floods have affected about 2.5 million people, causing 900 deaths and more than $ 1 billion in economic losses. In the Santa Catarina state, in the 1991-2010 period, about 5.7 million people were affected and 4,054 deaths were reported as results of these phenomena. This reality highlights the necessity for studies that can support flood control measures. Among these measures, flood maps have a non-structural character and can assist decision-making in relation to urban planning, increasing of public awareness regarding risk areas and evacuation routes. The Itajaí River Valley is known for flood events since its occupation and figures among the areas with the highest number of flood records in Santa Catarina. This study mapped the flood extent of Rio dos Cedros city urban area, medium Itajaí Valley, through the hydrodynamic mathematical model HEC-RAS, supported by a GIS. The following data were used: digital terrain model, hydrography map and orthorectified aerial image (1:10,000 scale), Cedros River discharge time series and field discharge measurements. Simulations were performed for events with return period of 2, 5, 10, 20, 50 and 100 years, and for a flood event occurred on 08/09/2011. The results indicated that the roads and buildings in the surroundings of the Cedros River bridge and the Ouro Creek and its tributary confluence region are more susceptible to flooding. In addition, show the absence of urban planning and the occupation of the watercourses natural flood areas. The model presented an underestimated result when compared to the flooded areas recorded in the 09/08/2011 event. This behavior may be due to the return of the Cedros River water by urban drainage system, and the possible backwater of the Cedros River in the Ouro Creek and its tributary. This study demonstrates the potential of use HEC-RAS model and GIS with high resolution spatial data for mapping highly susceptible flood areas.
Advances in Flood Risk Assessments for Data-Limited Changing Environments (PAP014415) - Full Paper
Keywords: Probabilistic Flood Risk, Hazard, Vulnerability
Subject: Floods in a changing climate
Abstract:
Developing countries have a recognized increasing need for reliable flood risk assessment and demand novel approaches due to the complex and evolving nature of hydrological and socio-economic conditions, limited availability of data, and, in some cases, lack of permanent inter-institutional collaborative arrangements for the assessment of flood risk. In the framework of the Probabilistic Risk Assessment Program at The World Bank, advances have been made in the development of methodologies that allow the estimation of flood risk considering these challenges. The application of one of these methodologies was carried out in the City of Boquete in Panama, where complex orographic, geological, hydrologic and hydrodynamic conditions dominate. In particular, the Caldera River, which crosses Boquete, causes frequent flooding in the urban area of the city. At the same time, the Caldera River Basin is one of the most important economic areas of the region because of its high natural, agricultural and touristic value. The results of the analysis show the need to continue investing in simplified approaches to meet data availability and computer capabilities conditions as well as the value of considering uncertainty into flood risk assessment. The analysis also acknowledges the need to further examine a balanced approach that also integrates additional robust and advanced tools to appropriately take into account the complexity of flood hazard assessment. The Boquete project had the involvement and participation of national and local government agencies in charge of water resources management and engineering, including potential users of the results generated. Therefore, this experience also sought to identify and define collaborative approaches that would lead to the adequate application and communication of risk information and the sustainability of flood risk assessments in Panama.
The Dutch Delta Model for Policy Analysis on Flood Risk Management in the Netherlands (PAP014418) - Full Paper
Keywords: Flood Risk, Policy Analysis, Public Participation, Probability, Model Integration
Subject: Floods in a changing climate
Abstract:
The Netherlands is located in a delta where the rivers Rhine, Meuse, Scheldt and Eems drain into theNorth Sea. Over the centuries floods have been caused by high river discharges, storms, and ice dams.In view of the changing climate the probability of flooding is expected to increase. Moreover, as the socioeconomicdevelopments in the Netherlands lead to further growth of private and public property, thepossible damage as a result of flooding is likely to increase even more. The increasing flood risk has ledthe government to act, even though the Netherlands has not had a major flood since 1953.An integrated policy analysis study has been launched by the government called the Dutch DeltaProgramme. The Delta model is the integrated and consistent set of models to support long-termanalyses of the various decisions in the Delta Programme. The programme covers the Netherlands, andincludes flood risk analysis and water supply studies. This means the Delta model includes models forflood risk management as well as fresh water supply. In this paper we will discuss the models for floodrisk management.The issues tackled were: consistent climate change scenarios for all water systems, consistent measuresover the water systems, choice of the same proxies to evaluate flood probabilities and the reduction ofcomputation and analysis time.
Qualitative and Quantitative Evaluation of Stormwater Infiltration Structures in An Urban Basin. Case Study: District of Campeche, Florianópolis-Sc (PAP014422) - Full Paper
Keywords: Quality of stormwater runoff, infiltration structures, monitoring
Subject: Urban Floods
Abstract:
The use of compensatory infiltration-based techniques for control of urban drainage should include a careful evaluation of the quality of infiltrated water in order to prevent the pollution of soil and groundwater. Pollution in stormwater can reach significant levels, and it cannot be ignored when it comes down to the quality of the receiving medium. The main objective of this paper was to develop a selection methodology to quali-quantitatively characterize rainwater infiltration structures used in an urban basin for future monitoring and instrumentation. The study was conducted in three stages. First, the most relevant infiltration structures were selected using the Geographic Information Systems (GIS) as a tool, together with hydrological models. Next, stormwater was qualitatively diagnosed and, finally, an infiltration ditch and an infiltration pit were characterized. This research study was conducted in the city of Florianópolis, Santa Catarina, Brazil. The methodological procedures consisted of a literature review, the physical characterization of the structures and the infiltration basin, and modeling of the basin based on physical and land use characteristics, by means of map databases provided by the municipality and the satellite images made available from the Corporate GIS project. The Quantungis 8.0 software was used for selection of stormwater infiltration structures. Qualitative analyses were performed at the Integrated Environment Laboratory (LIMA), Sanitary and Environmental Engineering Department at the Federal University of Santa Catarina. The main contribution of this study is the methodology which included field work, computational modeling and qualitative characterization of stormwater runoff and infiltration structures, thus helping decision makers employ stormwater infiltration structures based on scientific and technical criteria.
Increase Methods of Drainage Discharge of Inundated Water in Low Flat Land Considering Bed Deformation Characteristics (PAP014424) - Full Paper
Keywords: Inundation, Drainage method, Low flat land area, Meandering channel, Bed deformation analysis
Subject: Urban Floods
Abstract:
Drainage characteristics of inundated water on the lower Chao Phraya River in Thailand isintroduced. Furthermore, drainage methods of inundated water on low flat land areas have beendiscussed by use of the results of horizontal two dimensional bed deformation analysis. Installation ofshortcut channel in a fully developed meandering channel can decrease the water surface elevation in theupstream area of the shortcut channel. However, water surface level increases in the downstream area ofthe shortcut channel and risk of inundation increases there. Most of the confluences between the ChaoPhraya River and irrigation channels are located along the outer bank. However, water surface levelalong the outer bank is higher than that along the inner bank during floods. As a result, drainagedischarge of inundated water from the irrigation channel to a main channel will increase, if theconfluences between the main flow and irrigation channels are located along the inner bank. Furthermore,a groin at the upstream of the confluences can decrease the water surface level there. As a result,drainage discharge of inundated water from the irrigation channel to the main channel increases.
Risk Analysis for Flood Mitigation on the Raritan (PAP014427) - Full Paper
Keywords: Econometric Modeling, FEMA Insurance Payouts, Green Infrastructure, Hydrologic Modeling, Risk Assessment
Subject: Flood risk management in mega cities
Abstract:
We have developed a framework for flood mitigation risk analysis that applies generally to floods, and has applied it in this study of flood mitigation risk analysis for the Raritan Basin in New Jersey, USA. The framework we have developed involves a conceptual model of the relation among meteorological activity, hydrological models, infrastructure intervention, fine-grained topography, and economic impact. We have developed a hydrological model of the Raritan Basin. This model takes historical rainfall data, and has been calibrated to describe the behavior of one selected river gage during a significant 2007 flooding event. We have chosen one example of a mitigation strategy as a case in point to explore and develop the methodology, specifically Green Infrastructure. We used the calibrated model to compute the reduction in stream gage height (water level) over time as a result of implementing sufficient Green Infrastructure to reduce runoff depth by 1 inch (2.54 cm) throughout a relevant Watershed Management Area. In the econometric effort, we have developed a non-linear, threshold-based model that relates the cumulated or integrated amount of river activity above flood level to the FEMA insurance payouts, using historical data on both. This model was tested for four communities, and it achieves excellent predictive behavior against historical data, and can be used to relate the hydrological model results directly to FEMA payout records. Many possible explanatory variables were considered, and the most effective was found to be the aggregated quantity of water above flood level during the time directly associated to the flooding event that caused the claims and payouts. When these two streams of research are combined, the first is used to compute the effect of Green Infrastructure on the flow of water associated with an event. The second is used to calculate the corresponding decrease in total FEMA payouts. We applied this to one community, Manville, using rainfall data for a significant storm event that hit the region in 2007 to estimate runoff. Based on our models, the estimated cost savings due to the one inch (2.54 cm) reduction in runoff depth from Green Infrastructure in the region affecting the Manville Gage Station is about 6.1 million US dollars for a 68% reduction in FEMA payouts, which are estimated at 8.9 US million dollars without the mitigation. Our effort has demonstrated that linking of meteorology, hydrology, non-linear econometric modeling and sophisticated elicitation can provide a very powerful tool for informing and guiding discussion among all stakeholders. The present study, yielding non-linear models for four towns and hydrological models linked to one of these provides a proof of principle, a basis for estimating the costs of extending the model to the entire basin, and a roadmap for doing model-based and data-based risk analyses.
Organizing Community Participation for Flood Management: Effective Responses in An Urban Watershed in Belém (Pará-Brazil) (PAP014428) - Full Paper
Keywords: flood management, urbanization, urban watershed, floodplains
Subject: Flood resilient societies through community preparedness
Abstract:
Environmental and economic losses during flood events are the result of many factors which make the mitigation more difficult. The goal of this paper is to assess the range of impacts that experiencing recent flooding in Belém (Pará-Brazil) has had on people, their attitudes and behaviors; and to establish which measures work with particular population groups and locations in relation to flood prevention campaigns and flood warning/dissemination systems. The study employed both quantitative and qualitative approaches. The flood impacts in Belém are generated from both natural and human-made factors. Belém is located on former floodplains, where natural waterways and wetlands were replaced by urban structures. The results showed that floods affected people’s socio-economic livelihoods and critical aspects, such as health, education, housing, water, sanitation, property and assets. The implementation of the recommended measures could be carried out by different instruments and at various levels, such as the engagement of communities in moving permanently to higher grounds; the zoning of non-flood and flood areas; the deployment of systems to warn the populace about the risk; and the preparation of community plans of action explaining what to do in case of flooding. If the flood control devices work for preventing the events, some of the damage should be avoided.
Methodological Design for Flood Risk Assessment at a Local Level Using Scarce Information (PAP014429) - Full Paper
Keywords: Flood Management, Flood Risk, Urban Centers, Territorial and Environmental Planning
Subject: Urban Floods
Abstract:
Floods are the most frequent natural events in Colombia, recognized as the "socio-natural" threat that has most affected the country´s history, taking into account their high frequency, the large territorial areas involved and the amount of population that is affected. This paper shows the advances in the research that aims to provide the analytical and methodological tools necessary to strengthen the local territorial development processes. A methodology that can be applied and trusted, as the country has data, knowledge, and experiences, all limited by their conditions of quality and quantity. The methods used to perform each of the involved steps within the risk evaluation process, that is, the knowledge of the territory, analysis of the threat, and evaluation of the vulnerability, involve the investigation-action; the analysis of the document sources, historical archives, and databases; the performance of semi-structured interviews of experts and interest groups, surveys of homes, validation interviews, workshops, teledetection, geographic information systems-GIS analysis and census data. The research shows how the methodology can be applied by using two Colombian study cases and how it is possible to include it in the formulation of structured public action policies at local level, in the correction of medium and long term situations of vulnerability, in the construction of risk reduction scenarios and in other activities of territorial and environmental planning.
Cascade of Uncertainties in Flood Damage Estimations (PAP014432) - Full Paper
Keywords: Flood loss, hydraulics, vulnerability, hydrology, sensibility analysis
Subject: Flood forecasting and early warning systems
Abstract:
The quantification of flood risk involves several modelling steps each of which comprisesuncertainties. This work compares the impact of different sources of epistemic uncertainty in potentialflood damage estimates. We distinguish the uncertainties linked to models, methods and data, i.e. modeluncertainties; and the uncertainties correlated with the hypotheses and choices to be introduced in themodels, i.e. parametric uncertainties. In order to measure the global uncertainty of damage estimations,different data acquisition and modelling strategies were proposed for the four fundamental modules of theassessment: (1) hydrological analyses and considerations for determining discharges for different eventprobabilities; (2) the types of hydraulic model built and considerations when integrating topographical andbathymetric data; (3) the datasets and methods used to characterise the vulnerability of buildings tofloods; and (4) the damage functions used and the errors related to characterising the value of the stakes.We propagate uncertainties linked to different strategies in the assessment results (sensitivity testsrelated to each assessment module) and we measured the results variability generated. The method wasapplied to two case studies in the French part of the Rhine River basin. The results of this analysisshowed that the uncertainty of each module of the assessment depends on several factors that are highlydependent on the characteristics of the sites studied. However, the role played by flood hazard modellingwas preponderant in assessing flood risk to buildings, especially for the most frequent floods. Thisshowed that great attention must be given when modelling frequent floods for damage assessmentpurposes. The results of this study highlighted that the uncertainty linked to protection structures (dikesand dams) is a significant source of uncertainty in the damage assessment process.
Propagation of Hydraulic Modelling Uncertainty on Damage Estimates (PAP014433) - Full Paper
Keywords: Flood damage, Flood loss, Flood map, Vulnerability analysis
Subject: Flood forecasting and early warning systems
Abstract:
This work focuses on the impact of strategies used to model and map flood hazard indamage estimations. We consider different strategies to model the flood phenomenon, as a function of:(1) the type of hydraulic model used – 1D, hybrid 1D/2D or 2D software, i.e. model selection; and (2) thesimplifications made by the modeller when representing the topography and bathymetry of the riversystem, i.e. parametric choices. With this purpose, different hazard models and damage estimations wererealised in the town of Fislis, in eastern France. Hec-RAS, Mike 21 and Mike Flood hydraulic models wereused in order to measure the selection of model effects. We considered different scale of analysis (levelof details) when constructing the different modelling scenarios – density of cross-sections and hydraulicstructures (1D models), and the digital elevation model cell resolution (2D models). Thirty-two modelswere used to simulate floods with different return-periods. The 2D models tended to overestimate theflood surfaces and the 1D models tended to overestimate floodwater depths. The results of uncertaintypropagation tests on damage estimations revealed that the choice of the scale of analysis was the mainlyuncertainty influencing aspect of the evaluation. These parametric choices were responsible for 75% ofglobal uncertainty, against 18% for model selection. Furthermore, we notice that the increase of theprecision of hazard modelling has different impacts on flood maps and damage estimations, according tothe type of model. For 1D models, the more detailed the models are (higher density of cross-sections),the higher damage estimation results are. For 2D models, the more the models are precise (small gridcells)the lower damage estimates are. The results of damage estimations are strongly influenced byhydraulic modelling choices, therefore the production of flood maps for this purpose should be deeplyanalysed.
Seasonal Probabilistic Forecast of Tropical Cyclone Activity in the North Indian Ocean (PAP014435) - Full Paper
Keywords: Clustering algorithm, Seasonal forecast, sea surface temperature, tropical cyclones
Subject: Flood forecasting and early warning systems
Abstract:
Coastal flooding risk associated to tropical cyclones (TCs) is nowadays a major concern inlow-lying and populated areas of the North Indian Ocean (NIO). In the past few years there have beendevastating examples (i.e., Gonu or Phet in the Arabian Sea, and Nargis and Layla in the Bengal Bay)that encourages better understanding and predicting the activity of such events. Seasonal forecasting TCactivity would lead to a more efficient coping these phenomena and mitigate its destructive effects.It is well known that the TC genesis is boosted by warm sea surface temperature (SST), low to moderatevertical wind shear and upper level divergence. In this study we focus in the role of the SST as a neededprecondition for TCs intensification with a twofold objective: (a) to define a statistical downscaling modelto establish a relationship between large scale SST configurations and the occurrence probability of TCs;(b) to probabilistically forecast the occurrence rate of TCs in the NIO based on operational SST forecasts.To build the statistical downscaling model, Y=f(X), we apply a combination of the principal componentanalysis and the k-means classification algorithm in order to identify representative patterns of large scaleSST (predictor X) and the associated TC activity in terms of occurrence rate and expected tracks(predictand Y). Once explored the existing relations, we make use of the different runs of the NCEP’soperational forecast, Climate Forecast System v2 (CFSV2). By using different runs we are able toconstruct an ensemble forecast (probabilistic) of the TC activity for the next month/season. The proposedmodel reveals that this approach provides complementary and useful information for a very early TCwarning system.
A Practical Multi-Model Approach for Coastal Flooding Due to Tropical Cyclones (PAP014436) - Full Paper
Keywords: Astronomical Tide, Gonu, Storm Surge, Wadis, Waves
Subject: Floods in a changing climate
Abstract:
The modeling of coastal flooding due to tropical cyclones (TCs) is a challenge involvingmeteorologists, oceanographers, coastal engineers and hydrologists. Each element (wind, sea levelpressure, waves, surge, tide, response of coastal defences, run-off, river discharges) can be addressedwith a different degree of complexity, regarding the physical processes involved and the spatialresolution. A key issue is to balance the different components, obtaining an efficient, robust andmanageable method composed by a number of numerical and empirical models capable of being appliedfor the reconstruction of past TCs and also for the synthetic generation of possible TCs. In this work, wepropose a method based on the combination of a suite of atmospheric, hydrologic and hydrodynamicmodels. The methodology is applied to evaluate the coastal flooding associated to TC Gonu (June 2007)in Muscat (Oman), validating the results obtained qualitatively (pictures, satellite imagery) andquantitatively (buoys, tidal gauges).
Urban Flood in the City of Chilpancingo Mexico by Manuel Hurricane (PAP014437) - Full Paper
Keywords: Flood Management, Urban Flood, Chilpancingo City, Manuel Hurricane, Huacapa River
Subject: Urban Floods
Abstract:
The tropical torment called Manuel was a hydro meteorological event which presented inPacific Ocean near the Mexican coasts during last days of September 2013. This tropical tormentoriginated a large precipitation over the southwest of Mexican territory affecting the Guerrero State, andparticularly generating urban floods in the city of Chilpancingo, capital of the Guerrero State. It wasanalyzed the damage originated by the Huacapa River flood over the urban zone of this big city of thesouthwest of Mexico. Were also determinate the affected area and the possible causes that propitiatedthis urban flood applying hydraulic and hydrologic models.
Influence of Sediment Transport on Flow Conditions in the Vidoca River Watershed, São José Dos Campos-Sao Paulo-Brazil (PAP014439) - Full Paper
Keywords: urban water, sediment yeld, floods
Subject: Urban Floods
Abstract:
The aim of this study is to analyze how the transport of sediments interferes with flow conditions in the Vidoca River basin, which has an area of 60.08 km2 and is located in São José dos Campos,State of São Paulo, Brazil. The urban growth process in the city, an industrialized area, has contributed to an increase in flood frequency. The Vidoca River, an important tributary of the Paraiba do Sul River has been subject to erosion along its sides, with losses of culverts and bridges over the three last decades. Flow and sediment transport data for the watershed did not exist, so it was necessary to acquire them. The hydraulic data were measured during 12 field campaigns, from 2010 to 2013 in two sections. The velocities of flow were measured using either a MLN-07 current meter, or a smaller current meter, the FP101-FP201, and the water levels were measured with staff gauges. Samples of suspended sediments were collected using USDH-48 and USDH-49 samplers. The particle size analysis of solid samples of the background material and the analysis of concentration of total solids were performed in Institute of Aeronautical Technology (ITA) laboratories. The data were obtained through monitoring of liquid flow (Qlíq), suspended sediment concentration (Css), precipitation (P), water level (h), topography, and particle size, which were used to obtain the discharge and the relationships for rating curve and sediment yield curve. The results showed that Senhorinha Creek, a tributary located in the upper watershed, presents supercritical flow for Froude numbers ranging from 2.05 to 0.8 in the upper stretches, provoking bank and bottom erosion, thus leading to an increase in the sediment transport. Discharge and water level data were analyzed to establish the rating curve; the discharge varied from 0.50 to 64.52 m3/s. The sediment yield curve showing liquid discharge flow and solid discharge flow presented a coefficient of determination equal to 0.94.
Risk Assessment of Rainstorm Disaster in Guangxi Based on Multi-Source Data (PAP014447) - Full Paper
Keywords: rainstorm, risk evaluation, Gis, Guangxi
Subject: Land use and Floods, landslides and erosion
Abstract:
In order to cope with the frequent rainstorm disaster and its increasingly adverse effects on Guangxi Zhuang Autonomous Region,Principal Components Analysis (PCA) and Analytic Hierarchy Process (AHP) methods are used on the bases of GIS with multi-source data involving meteorology, historical disaster events, social economy and geography of Guangxi, to develop a data sequence processing and quantitative technology. By which, a rainstorm disaster risk evaluation model has been developed, including four kinds of factors: the dangerousness of real time rainstorm, the sensibility of hazard-formative environment, the vulnerability of receptors and the regional capacity of disaster resistance. Then, the spatial distribution map of rainstorm risk level evaluation in Guangxi has been developed by using the model, and the verification results in this paper show that the risk evaluation results consistent with actually happened disaster condition well.
Flash Flood Incidents in China in 2013:Characteristics, Reasons, and Benefit Analysis of Non-Engineering Measures (PAP014494) - Full Paper
Keywords: flash flood, creek flood, landslide, debris flow, non-engineering measures
Subject: Land use and Floods, landslides and erosion
Abstract:
Fatal flash flood incidents in 2013 in China were sorted based on statistical data from theOffice of State Flood Control and Drought Relief Headquarters and provincial flood reports. Throughstatistical analysis and field research, the incidents were categorized based on regional distribution,historical comparison, disaster type and level, occurrence time, and composition of fatalities, and nationalflash-flood-distribution maps drawn according to disaster type and level, and number of deaths.Furthermore, the ratio of deaths by flash floods to total deaths by flooding since 2000 were analyzed, andthe situation of flash floods in 2013 compared with 2012. The results showed that of 774 people killed byflooding in 2013, 560 (72.4%) were killed following 181 catastrophic flash flood incidents. Flash floodincidents started in early February, ended in late October, and occurred mainly in July and August,although there were significant regional differences in distribution and severity. Migrant workers, farmers,and tourists were the groups most affected, and the elderly and minors accounted for the largestproportion of total deaths. Extreme heavy rainfall, migrants’ poor awareness of flood prevention, andfailure of early warning information were the principal reasons for the frequency of flood disasters andnumber of casualties.
A Comparative Study on Methods for Loss of Life Estimation - Applications to Case Studies in the United States (PAP014528) - Full Paper
Keywords: Loss of life, Consequences, Flood Risk Analysis, Evacuation, comparison effort
Subject: Flood risk management in mega cities
Abstract:
Both in the USA and in the Netherlands extensive studies on approaches for identifying flood risks- the combination of levee failure probabilities and consequences are ongoing. Important elements of these studies are methods to analyze life loss for floods and the effectiveness of evacuation and emergency management. Both in the Netherlands and the USA, the risks to life associated with flooding are also taken into account in the national policy. It is therefore important that the methods that are utilized to analyze risks to life are well-validated. The main objective of this study is to compare Dutch and American methods for the analysis of loss of life and evacuation for a number of case studies in the US (i.e. a comparison effort). In the first part an overview and comparison of methods for loss of life estimation and evacuation analysis that have been developed in the Netherlands and the United States. In the United States HEC FIA and Lifesim are used, which are more process-based models that take into account the dynamics of flooding and people movement in the area. The Netherlands used empirical curves to relate mortality to flood conditions. The potential for evacuation in the Netherlands is analyzed using a combination of macro-scale traffic models and response time. Similarities and differences between the modeling approaches and input and output types are discussed. In the second part of the studies a number of case studies have been selected as part of the comparison effort. The Natomas Basin in California is a low-lying area with a population of about 100,000 and is threatened by flooding from the Sacramento river. The various modeling approaches give very different outcomes for the life loss and these are dependent on the different responses of the various models to the large flood depths (up to 5m) that can occur. Also, the potential for evacuation of the Natomas Basin is analyzed, and depending on evacuation efficiency the required time for evacuation for the basin ranges between 7 hours and more than 24 hours. A second case study concerns the Herbert Hoover Dike in Florida, a large dike on Lake Okeechobee with two small communities in the vicinity. For this breaching scenario water depths and flow velocities are more moderate and differences between model outcomes are smaller. These cases are the first steps in a benchmark research on life loss models. It is discussed how the empirical basis of life loss models can be improved, e.g. by using available datasets for the life loss due to the flooding of New Orleans during hurricane Katrina (2005). In a further comparison and benchmarking effort other models and empirical datasets can be added.
Integrated Flood Management Approach to Combine Urban Generated Floods and Ecosystem Services Preservation (PAP014678) - Full Paper
Keywords: Urban expansion, Urban flood, Full bank discharge, Stream-bed incision, Aquatic ecosystem
Subject: Urban Floods
Abstract:
This article exposes a strategy for managing flood risk that would be implemented in areas that are prone to rapid urban expansion. We take here the opportunity of a well document periurban watershed (150 km2) located in the vicinity of Lyon city (France) and where large investments from national, regional and local authorities have been devoted since 2008 to reduce urban pollution sources and the hazard of hydrological extremes, flood and drought. These actions contribute to restore lost ecosystem services like bio-assimilation and transformation of organic substances improving global surface water quality, human health and providing societal economic benefits. Predicted urban development would however compromise these efforts in the near future. It means that rapid periurban development should integrate both flood management risk it generates for near densely urban system it grows around and preservation of new stream water ecosystem it affects.To address this issue, we develop on this periurban watershed a probabilistic based hydrological modeling of its flood regime. Only the landscape change is considered at this stage, arguing here that climate change will have less impact on the mid-term horizon of 2030. Main working hypothesis is to assume on-site rain water retention implementation for new constructions expected on 2030. This is to increase flexibility in controlling urban floods. A constraint is however to maintain occasional overflows from sewer systems to ensure protection of downstream dense urban areas against pluvial flooding. At the same time we consider to prevent receiving stream ecosystems from geomorphic and water quality damages as to keep ecosystem services working.
From Theory to Practice: Can We Really Value Coastal Flood Impacts? (PAP014681) - Full Paper
Keywords: Coastal flooding, impact assessment, vulnerability, systemic, sustainable development
Subject: Impact of climate change on flood risk
Abstract:
Extremes events in combination with the increasing population on coast, future sea levelrise and the deterioration of coastal defences can lead to catastrophic consequences for the coastalcommunities and their activities. The current paper describes the methodologies used to develop a set ofcoastal vulnerability indicators for receptors exposed in different European sites. A comprehensive andmeaningful understanding of the vulnerability of the coastal system can only be achieved through aholistic analysis of various components of vulnerability. Vulnerability data has primarily been collectedfrom existing European and National datasets supplemented by an exhaustive literature review. Whereasmethods for assessing direct costs to the built environment have been developed in most parts of Europeas a mean of producing cost-benefits assessment of flood risk management project, assessing thepotential impacts on the population and the environment remains rather limited. Much more difficult toevaluate is the dynamic response of the economic, environmental and social systems to this shock sothat the resilience of these systems to external perturbations can be determined. This evaluation remainsnevertheless essential for understanding the sustainability of coastal system in the face of extremethreats. Yet the availability of data for the different vulnerability components is variable. Significant issuesremain in terms of data collection and availability to enable validation and to reduce the uncertaintyassociated with their assessment. Therefore it is often necessary to either use an averaged vulnerabilityindicator or to transfer a specific one from one region to another.
Flood Forecast Quick Modelling (PAP014684) - Full Paper
Keywords: Flood Management, Flood Early Warning, Forecasting, Geoprocessing, Runoff
Subject: Flood forecasting and early warning systems
Abstract:
The aim of this project is to provide a quick tool for water level variation forecasting and early warnings at telemetric river gauges supporting Civil Defense activities. Its use is meant for river basins with natural flow patterns under the coverage of meteorological radar and no hydrological forecasting available.
Flood Information System (Tabis) for Turkey (PAP014691) - Full Paper
Keywords: Flood maps, Flood modeling, GIS, GeoPortal, Hydroinfomation
Subject: Flood forecasting and early warning systems
Abstract:
Flooding is a serious natural disaster in Turkey similar to rest of the world causing significant economical damage and loss of lives every year. Unlike many other natural hazards floods can be predicted ahead of time. Developing real-time flood event prediction models and early warning systems helps minimizing the economical damage and risk of loss of lives. Also hydrologic and hydraulic modeling of the probable floods and developing flood hazard maps allows to proper planning of flood prevention and protection measures. Both the real-time flood event prediction models and hydrologic-hydraulic modeling of flood involve huge amount of data from several disciplines. Turning the atmospheric, meteorological, topographical, hydrological and hydraulic data into information about flood at different complexity levels for researchers, decision makers, operators, and public requires comprehensive modeling and information management systems. This study attempts developing a base platform (TABİS) for such a flood modeling and information system for Turkey. TABİS is a web-based platform that allows real-time acquisition, storage, management, and displaying the entire flood related static and time series data. The static data in TABİS involve water body layer, hydrologic basin boundary layer, flood protection structures layer, historic flood event locations and facts. The time series data involve radar rainfall and flow measurement data. There are other background layers such as administrative boundaries, roads, aerial images, land use / land cover maps etc. TABİS also stores and displays pre-developed flood maps for the available flood study areas. TABİS is aimed to be the platform for researchers, engineers, decision makers, and public to produce, store, model, and share all the flood related data and information in Turkey.
Flood Forecasting on the Tocantins River Using Ensemble Rainfall Forecasts and Real-Time Satellite Rainfall Estimates (PAP014692) - Full Paper
Keywords: Hydrological Forecasting, Ensemble, Flood Control, TRMM Real-tome
Subject: Flood forecasting and early warning systems
Abstract:
The Tocantins River, located at the northern region of Brazil with over 300.000km² of drainage area, is a very important water body in terms of hydropower production, having six major hydropower plants on its main channel. The occurrence of floods along the Tocantins River is not only important for hydropower plant operation, but also is a relatively frequent event that affects several cities and their inhabitants. One recent example happened in 2012, when a flood with a relatively low recurrence time (approximately 2.5 years) caused damages to cities located close to the river. Motivated by this flooding susceptibility, a hydrological forecasting system was developed in order to assist the decision making of dam operation along main river axis, taking advantage of the existence of telemetric information from the hydropower plants. The forecasting system is being used operationally since mid-2012 and is based on the MGB-IPH model, a large scale distributed hydrological model. The model uses rainfall information from ground based telemetric gauges and real-time TRMM satellite rainfall estimates, which are merged together in order to reduce the impact of the lack of observed information in the basin. Streamflow forecasts are obtained based on quantitative precipitation forecasts from two different sources: (i) the Brazilian CPTEC Eta 15km regional deterministic model, and (ii) NOAAs Global Ensemble Forecasting System, maintained by the National Center for Environmental Prediction (NCEP-NOAA). All the forecasting system data management and operation is conducted through a specifically-designed computer interface, coupled with an open-access GIS platform. We present the forecasting system and show hindcasting analysis of how the 2011/2012 rainy season flood could have been predicted with the use of ensemble forecasts. We also compare results of deterministic and ensemble forecasts during the rainy season of 2012/2013.
Study on Disaster Risk Assessment and Area Business Continuity Planning in Industry Agglomerated Areas (PAP014702) - Full Paper
Keywords: disaster risk assessment, business continuity, Area BCP, Area BCM, economic resilience
Subject: Flood risk management in mega cities
Abstract:
Two large disasters which occurred in 2011, the Great East Japan Earthquake and the Flood of Chao Phraya River in Thailand, reminded the risks of business termination and further impacts on national, regional and the global economy through their supply chain. Prearranged Business Continuity Plans (BCP) or Business Continuity Management (BCM) System (BCMS) in private enterprises helped them survive to some extent but finally malfunctioned in continuation of their business or quick recovery from damages due mainly to disruption of business resources such as energy, water, transportation and communications that are essential for their operation.In order to minimize the negative economic impacts or losses particularly by large scale disaster that disrupt fundamental infrastructure in wide areas, it is important to carry out risk assessment at a proper scale and to prepare scenario based disaster management plans for area-wise damage mitigation and strategic recovery. All players should share the plan and coordinate with other player’s actions. In addition, it is essential to establish framework of integrated resource management at a scale of a whole industrial area for effectuating each enterprise’s BCM actions in coordination with the public sector’s actions.In 2013, Japan International Cooperation Agency (JICA) proposed a new concept of disaster risk management in industrial agglomerated areas, as “Area BCP” and “Area BCM”, applying to a project in three pilot areas of industry agglomeration in ASEAN region for the first substantiation of the concept.The Area BCP designates a framework and direction of coordinated damage mitigation measures and recovery actions of stakeholders including individual enterprises, industrial area managers, local authorities and administrator of the infrastructures in order for business continuation of area-wise economy such as industrial agglomeration or urbanization.The Area BCM then is defined as a cyclic process of risk assessment, sharing risk and impact information, determining common strategy of risk management, developing the Area BCP, implementing the planned actions and monitoring to self-improve the Area BCM System recurrently in coordination among stakeholders, in order to enhance the capability of effective business continuity of the area.The three pilot areas selected are Bekasi - Karawang industry area in Indonesia, Cavite - Laguna - Metro Manila in the Philippines and Hai Phong industry area in Vietnam. In each area, many stakeholders from public and private sectors have been participating to the project.Although the project is still in a first cycle of the Area BCM process, some important lessons can be explored from the conducted steps of multi-hazard risk assessment, disaster scenario projection, business impact analysis and discussions among stakeholders to formulate the Area BCP. This paper aims to identify the benefits and further challenges of the new approach for enhancing resilience of local economy.
Rainstorm Risk Degree Real-Time Evaluation System Based on Gis for Guangxi (PAP014703) - Full Paper
Keywords: rainstorm, risk degree, real-time evaluation system, Geographic Information System (GIS), Object-Oriented Programming (OOP)
Subject: Flood risk management in mega cities
Abstract:
Aiming at the real-time evaluation of rainstorm disaster risk level methods that lack of elaborate and quantitative presently, this paper applied meteorological data, historical disaster data, height and distance from the sea of Guangxi, and confirmed the identification technology and data sequence building method of hazard -formative factors of rainstorm of Guangxi based on hazard-bearing body , the hazard -formative environment, hazard -formative factors ,and anti-disaster capability. Real-time evaluation model and grade index of rainstorm disaster risk level were constructed for different hazard-bearing body ,such as agriculture and social economy, based on risk, subsequently environment fragile degree, vulnerability and anti-disaster capability. And then rainstorm risk level real-time evaluation system was developed, with real-time evaluation model as the core, by the GIS secondary development technologies, to simplify and standardize the operating process of rainstorm risk level real-time evaluation. Evaluated the violent typhoon named Neuchatel on September 29, 2011 by using this system, the results of experiments consistent with disaster condition.
Assessment of An on Site Stormwater Detention Reservoir Operation With the Volume Required by Belo Horizonte's Legislation (PAP014706) - Full Paper
Keywords: OSD - On-site Stormwater Detention, damping of peak flows, urban drainage
Subject: Urban Floods
Abstract:
This article analyses the operation of an OSD tested at laboratory scale, with the volume required by land use and occupation law of Belo Horizonte to compensate the total of waterproofing in a lot of 360 m². The hydrograph generated for the lot under those conditions was simulated for a rainfall for 10 years of Return Time and 30 minutes of duration and the damping provided by the OSD was analyzed for seven different outlet pipe diameters: 3/4"(20 mm), 1" (25 mm), 1.1/4" (32 mm), 1.1/2" (40 mm), 2"(50 mm), 2.1/2" (60 mm) and 3"(75 mm). In accordance with the specifications of Sudecap (2008), the minimum diameter of the discharge outlet of the OSD should be 75 mm. The results of the tests showed that the volume defined by the legislation is less than the required to achieve the desired peak flow damping. It was noted also that even if the OSD has a sufficient storage volume, the discharge pipe with a diameter of 3" does not restrict the input hydrograph peak.
Towards the Development and Evaluation of Adaptive Flood Risk Management Strategies for the Rhine Estuary - Drechtsteden (PAP014707) - Full Paper
Keywords: Flood Risk, Adaptive Management, Cost-benefit Analysis, Decision Support, Tools
Subject: Floods in a changing climate
Abstract:
Flood risk in the western part of the Netherlands will increase due to climate change,socioeconomic development and subsidence if no measures are taken. The Delta Programme is looking100 years ahead to develop a flood risk management strategy which, in light of future uncertainties, isboth flexible and robust. Different possible strategies have already been studied in previous phases of theprogram and some choices have already been made. The preferential strategy will be a strategy whichbuilds on the present system of strong dikes and flexible barriers. Within this strategy, opportunities existto replace part of the necessary dike reinforcements with room for the river measures. In this paper wedescribe and apply a dynamic framework for the development and subsequent economic evaluation ofthose strategies.
Control Flooding at Low Areas of Marginal Expressway Tietê River in the City of Sao Paulo, Brazil (PAP014709) - Full Paper
Keywords: Control Flooding, Polder System, Tietê River, São Paulo
Subject: Urban Floods
Abstract:
The construction of marginal highway to the Tietê River in São Paulo between the Penha’sdam and the Mobile Dam had interference from existing ones and that due to road template; the greidelane under the bridge was lowered. With the lowering these points emerged lows for the Tietê Riverwould become sections restrictions. From the Drainage Master Plan of the Upper Tietê Basin, expandingthe flow capacity the Tietê River through a work of enlargement and lowering of the background,identified the lows that caused restrictions even after the expansion work of the underground channel. Inthese places we adopted the system for protection Polder of the low area as well as in the Netherlands toadopt the same system of protection of their areas situated below sea. In 2010, after the completion ofthe capacity expansion the Tietê River, there was a flood of sites that did not have the protection systemPolder. This study identified and performed the project for implementation of the protection program of thelowland areas of the marginal route the Tietê River in São Paulo, resulting in six protection areas.
Adaptation Measures and Pathways for Flood Risk in Dordrecht (PAP014714) - Full Paper
Keywords: Adaptation Pathways, Adaptive Delta Management, Dutch Delta Programme, Flood risk, Multi layer safety
Subject: Flood resilient societies through community preparedness
Abstract:
In line with the Adaptive Delta Management approach of the Dutch Delta Programme,Dordrecht has developed a multi-layer safety strategy to meet the future tasking for flood riskmanagement. This strategy puts greater emphasis on limiting the consequences of floods through spatialplanning (layer 2) and emergency management (layer 3), in addition to protection from floods throughdikes (layer 1). The reasoning process and measures related to the new strategy are as follows.The proposal of the Delta Programme sub-programme Safety for updating the protection standards hasmade it possible to invest in strengthening specific dike segments, where it is most cost-efficient. Bytransforming the northeastern dike segment into an extra strong dike, Dordrecht can be safer than with aneconomically optimal standard for the entire dike ring -- for about the same cost. This targeted measure inlayer 1 is sufficient to meet the basic safety level (chance of fatalities is not higher than 1/100,000) andreduces the risk of social disruption (large groups of casualties) to virtually none.Economic damages and casualties due to a dike breach in the Northwest or in the South can be reducedby using regional defences as compartmentalisation (layer 2). In addition, compartmentalisation of thedike ring area enables the creation of a "safe haven" for preventive evacuation on the island itself (layer3). This also calls for thorough preparation for floods, e.g. by robust design of critical infrastructurenetworks and improved risk and crisis communication.The multi-layer safety strategy for Dordrecht ensures that the objectives for flood risk management aremet in a timely and efficient manner, that opportunities for mainstreaming adaptation and for spatioeconomicdevelopment are taken advantage of, and that unnecessary costs of potentially irreversiblemeasures are avoided.
Effects of Climate Change on Flood Risk and Sustainable Development in South Africa (PAP014716) - Full Paper
Keywords: Climate Change, Distribution Models, Flood Frequency, Peak Discharges, Rainfall
Subject: Impact of climate change on flood risk
Abstract:
Climate change poses a great risk to South Africa which has a dual agricultural economy. In the recent years, the country has experienced extreme weather events with floods resulting from higher than normal rainfall. The negative impacts manifest in infrastructure damage, disruption in the supply of agricultural products and damage to crops. In order to understand the dynamics involved in the effects of climate change, peak discharges for Luvuvhu River catchment were used to evaluate flood frequencies, based on flood events with a certain probability of occurrence or exceedance. Frequency distributions were used to describe historical characteristics and magnitudes of floods. Flood peaks corresponding to 2, 5, 10, 50, 100 and 200 years were estimated for flood prevention. The extreme value analysis showed that the Gumbel and Log Pearson type III distributions provided the best fit which could be used to derive the probability of occurrence of flood events. The results showed a general increase in the frequency of extreme rainfall events, accompanied by floods of higher magnitude for the small to medium floods.
Urban Runoff Source Control Measures in São Paulo: Technical and Legal Aspects (PAP014718) - Full Paper
Keywords: storm water regulation, source control, urban drainage planning and management
Subject: Urban Floods
Abstract:
New urban developments may cause serious inconvenience on urban drainage systems when their hydrologic impacts are not properly mitigated. Many cities around the world tried to minimize the effects of urbanization by implementing source control measures encouraged by regulations, laws or ordinances. In many cases, the introduction of this type of solution has led to adverse outcomes, not only because of the choice of the device, but also due to regulations control standards. This study evaluated four different urbanization scenarios in order to analyze São Paulo´s ordinance efficacy on controlling hydrologic impacts of new developments. Among these scenarios, the installation of micro reservoir and rain gardens were evaluated. Results showed that it would possible to attenuate peak flows from source controlled areas by 20%., and by 11% and 9% considering the contribution from the whole development of the catchment, respectively. When the location of the micro reservoir was changed, it was possible to double the attenuation efficacy. The use of rain gardens showed worse results for peak flow attenuation. However, these devices can reduce by 64% the number of runoff events from controlled areas, which are strongly linked to water quality. It was concluded that the existing law (municipal law 41.814/02 and state law 12.526/07) only partially meets its goal for flood control. The law presents a good opportunity to increase the effectiveness of urban drainage systems and its contents should be revised in order to allow non point source pollution control and urban river degradation.
Societal Flood Fatality Risk Assessments: An Advanced Probabilistic Method and Its Application to the Rhine-Meuse Delta (PAP014719) - Full Paper
Keywords: Flood Risk Analysis, Fatality Risk, Societal flood risk, The Netherlands
Subject: Impact of climate change on flood risk
Abstract:
In the Netherlands the possibility of societal disruption by floods plays an important role in the discussion on future flood risk management strategies. One of the indicators to assess societal disruption is societal flood fatality risk. Societal flood fatality risk is related to the probability of many fatalities during a single event. In deltas protected by flood defences, such as the Nether-lands, impacts of extreme events depend on the location and number of failures in the flood de-fences. The number and location of breaches depend on the failure probabilities of the embank-ments and the flow of river water through the breaches into the flood-prone areas. These flows reduce the river water levels and discharges and thus the probabilities of failures downstream. This retention effect proved to be very relevant. The assessment of flood risks in deltas protected by defences requires an advanced method which enables (1) the joint analysis of both storm surges and river discharges (2) the incorpora-tion of hydrodynamic interaction of loads and breaches at different locations to include the re-tention effect and (3) a complete and dynamic analysis of flood probabilities, breach growth, flood patterns, and flood consequences. The new developed method meets these requirements. The method results in FN curves which provide the probability of events with N or more fatali-ties. Results further include the potential loss of life (expected annual number of fatalities) and the contribution of the subareas to the total societal flood risk. The method also gives insight in which flood scenarios contribute most to societal disruption. To enhance the discussion on flood risk management strategies, the outcomes were compared with various views on potential toler-able risk levels from different countries and scientific fields. The paper discusses the method, its application to the Rhine-Meuse delta and the use of the out-comes in the discussion on future flood risk management strategies.
Urban Flooding Evaluation for the Osório Creek Sub-Basin Vicinity in the City of Maringá-Pr, Brazil (PAP014721) - Full Paper
Keywords: Scenarios in urban drainage, Urban flooding, Structural control measures, Non-structural control measures, Computational modeling in urban drainage
Subject: Urban Floods
Abstract:
The main reason of urban flooding in the Brazilian cities is the deficient urban planning, which includes the design of the drainage systems and the occupation of the land in the watersheds. The urban floods are sources of socioeconomic problems to the local population. They can propagate diseases and offer risk to people's lives in the affected areas. The aim of this study is to develop a computational model to perform simulations of different flood scenarios. A case study was carried out for the district of Porta do Céu in the city of Maringá-PR, Brazil. Field data was collected and the inconsistencies were corrected. The model was implemented by using Bentley® SewerGEMS® v8i software. Three scenarios were analyzed and the results demonstrated that the current drainage network is underestimated. However, it is possible to execute structural and non-structural measures for flood mitigation in the region.
The Value of a Coastal Flood Risk Assessment for the City of Vancouver in a Changing Climate (PAP014723) - Full Paper
Keywords: Flood Risk, Sea Level Rise, Climate Change, Urban Flooding, Gap Analysis
Subject: Floods in a changing climate
Abstract:
The City of Vancouver, Canada, has recognised that despite global mitigation efforts, climate change will impact the City’s future. Anticipated impacts include more intense and frequent wind and rain storms and sea level rise. Adaptation to these climate changes will require a mix of policy, planning and engineering responses. Prior to identifying preferred mitigation strategies, a comprehensive understanding of the consequences of sea level rise and ocean flooding is required. The City of Vancouver is undertaking a coastal flood risk assessment (CFRA) to acquire a broad base of technical, policy and planning knowledge that will be used to develop a robust and defensible approach to flood risk.A multi-disciplinary consultant team is working together with the City to develop the inputs for a risk assessment, including inundation mapping, vulnerability assessments and an asset inventory. These data sets together with flood damage information from HAZUS, a flood consequence tool developed by US FEMA and supported by Natural Resources Canada, was be used to look at consequences to coastal flooding.Over the course of the project, the team has recognized the many uncertainties and gaps in the process of developing a CFRA for a modern, dense, urban city such as Vancouver. Especially when considering the long planning horizons required to prepare for and adapt to sea level rise. This paper highlights the many obstacles and gaps in the assessment, but also describes the inherent value of the process and results. These include increased understanding of hazards and vulnerabilities, and the development of useful visual tools for engagement, planning and education.
Use of Porous Concrete in Parking Areas for Improving Urban Drainage (PAP014726) - Full Paper
Keywords: Flood Management, Urban Drainage, Permeable Pavement, Porous Concrete
Subject: Urban Floods
Abstract:
As urban development causes changes on the quality and the quantity of the runoff due to rain events, cities used to adopt technical measures in order to compensate for the human action in urbanized areas, trying to restore or improve the original conditions of drainage or, at least, mitigate the negative impacts. Adoption of porous concrete in parking areas is an example of such measures. This paper aims to present an assessment of performance of porous concrete pavement in reducing runoff generation when applied in parking places. The experiments were carried out at the Brazilian Army’s Headquarters, in Brasilia, Brazil. The relationship between the performance of the drainage and the state of the pavement was evaluated in three different situations (new, clogged and recovered concrete). For this, a paved area of 37.5 m² allocated to three parking spaces for light vehicles. Each of the place was built with 15 cm thick of concrete over a drainage bed of 30 cm thick, adopting differences in the paving construction technique. The evaluation of the hydraulic performance of the pavement occurred through results obtained from runoff generated by artificially simulated rain. The rainfall simulations were performed first with the new pavement. In such experiment, the porous concrete absorption ability was higher than 2.35 mm/min, since the volume of the rain, generated adopting this intensity, was fully conducted into the draining bed. Subsequently, new measurements found a decrease of the permeability when the pavement was clogged. After a surface cleaning, adopting the same simulated rain of 2.35 mm/min, the maximum infiltration rate observed reached 1.75 mm/min. One can conclude that the recovery of the permeability was not completely successful. Therefore, the solution studied by using the porous concrete can play an important role in attenuation of peak flow of rainwater in urban areas, although its efficiency is conditional to maintain the drainage capacity of the floor.
Infiltration Capacity of Interlocking Concrete Pavement (PAP014730) - Full Paper
Keywords: interlocking concrete pavement, lysimeter, Permeable Pavement
Subject: Urban Floods
Abstract:
This paper has for objective to evaluate the infiltration capacity of the interlocking concretepavement, used two lysimeters (construction in reduction scale), being one with grassy and another onewith the interlocking concrete pavement. These lysimeters had been installed in opened area, in order tobe in contact with the local conditions, of precipitation. Each lysimeter possess two reservoirs, one insuperior, for the collection the superficial runoff, and the inferior for the infiltration water. One lysimeterwas elaborated with proper the local ground (Red Nitosol) and the grass. The other Lysimeter wasconstructed with the different layers, having been the gravels, cover of a permeable geotextile, aggregatebedding course and the interlocking concrete pavement, with joint width 6 or 7 mm. The experimentsshowed that the performances of two lysimeters were similar
How to Assess the Benefits From Early Flood Warning Systems? (PAP014732) - Full Paper
Keywords: Hydrological forecasting, reliability, risk assessment, flood risk management, efficiency measures
Subject: Flood forecasting and early warning systems
Abstract:
The objective of this paper is to assess the reliability and the efficiency of early flood warning systems (EWS) in small river basins exhibiting short hydrological response times. The reliability expresses the hydrological quality of the forecasts for different lead times. The efficiency evaluates the socio-economic benefits from a forecasting system characterised by the ratio of reduced damages dependent on lead time and the costs of the early warning system. The assessment is performed in two steps: first the reliability of early warning system is evaluated by analysing the performance of an EWS over several years and by considering true and false alarms. Second, the economic effectiveness estimates the potential benefit in form of avoided damages in an event dependent evaluation. The combination of reliability and avoided damages leads to the warning expectation as an indicator for the optimal alert.EWS as a non-structural protection measure induce very low detrimental effects on the natural environment and can be quickly implemented. Here, experiences from an Austrian case study from a pre-alpine catchment are described demonstrating the application of the proposed methodology.
Discussion About the Practicability of Implementing Flood Risk Management and Urban Flood Insurance in China (PAP014733) - Full Paper
Author(s): Longhua Gao and Xiaoqing Zhou
Keywords: flood risk management, urban flood insurance
Subject: Urban Floods
Abstract:
This paper explains the flood risk management at first, and then analyzing the insurability for flood insurance by learning the international researches and developments of it, thereby finding out what the success or failure hinge on in practical case. On the basis of above, this essay do further research on the requirement practicability of implementing urban flood insurance in China, thereby pointing out various problems which may be occurred and advancing approaches to deal with them. Finally, paper offers exercisable proposals to the implement of Chinese urban flood insurance system.
Mathematical Modelling Support to the Pdmat-3 Study for São Paulo (PAP014736) - Full Paper
Keywords: Flood management, flood control, flood forecasting, numerical simulation, SOBEK model
Subject: Flood risk management in mega cities
Abstract:
São Paulo is a typical example of a fast growing city where the development of the primary drainage system has not kept pace with the increased runoff from the newly urbanized areas. Recently, the third Drainage Master Plan (PDMAT-3) for the Upper Tietê Basin has been completed. Although during the past few years many detention basins have been built and drainage channel capacities have been increased, persistent flooding occurs, primarily on the roads and highways along the main drainage routes. This leads to significant economic losses, primarily due to the interruption of transport. For the first time in the sequence of studies a fully integrated numerical simulation model was developed and applied, based upon Deltares' modelling system SOBEK. The model consists of the following components: (1) rainfall runoff models for 100 up to 400 subcatchments (depending on the discretization level applied), using the SOBEK linear urban runoff and SCS concepts; (2) 1D models for the principal rivers and drainage channels; (3) Real time control (RTC) module for the control of weirs, gates and reservoirs; and (4) overland flow (2D), implicitly connected to the 1D schematization. The SOBEK model covers a catchment area of 5.700 km2 with an urbanized area of 2300 km2 and a population of approximately 19 million. The model has been developed in three discretization levels, where more refinements were progressively introduced, based upon additional data collection. The paper addresses a state-of-the-art method with which rainfall data were generated for the calibration and validation events. Rainfall measured at 111 ground stations were used to calibrate the spatial distribution provided by instantaneous radar images. Processing of the rainfall data was based upon the Delft-FEWS system of Deltares, where the rainfall on each individual catchment could be estimated more precisely than on the basis of the ground stations alone. The paper also addresses the calibration and validation procedure, various application issues, as well as some practical problems that were encountered during the development of the model and the way in which these were overcome.
Robustness Analysis for Flood Risk Management Planning: on Risk-Based Decision Making Beyond Simple Economic Reasoning, Exemplified for the Meuse River (Netherlands) (PAP014737) - Full Paper
Keywords: Flood Risk Management, Climate Change, Robustness, Cost Benefit Analysis, Uncertainty
Subject: Impact of climate change on flood risk
Abstract:
Flood risk management planning involves making decisions on which measures toimplement, and when to do so. Rational decision making on which comprehensive strategy to implement,or on which measures to take first, requires ex-ante assessments that question whether flood risk iseffectively reduced, and against which societal costs. Such decision making is usually supported by costbenefit analysis (CBA) or cost effectiveness analysis (CEA). The key economic assessment criterionapplied may be the ratio between the benefits and costs of a measure or strategy (B/C), or, alternatively,the minimum of the sum of costs and (residual) flood risk. However, these metrics treat lowprobability/large consequence risk and high-probability/small consequence risk as equal, which is oftenconsidered unsatisfactory in a decision making context. Robustness analysis can be used to account forthis ‘flaw’, as it gives insight into the relationship between flood magnitude and flood consequences at thescale of an entire flood risk system, thus revealing how sensitive such a system is and whether it can stillrecover. A more robust system is able to deal with a variety of extreme floods, including those thatexceed the ‘design flood’. This paper examines how a variety of strategic alternatives for flood riskmanagement along the Meuse River in the Netherlands score on various economic criteria and how theywould be assessed from a robustness perspective. The strategies include making room for the river,strengthening embankments, and various combinations of these. The results show that the three criteriaindeed lead to a different ranking of which strategy to prefer. This supports our claim that a robustnessperspective may help to select a strategy that is not only economically efficient, but may also be moresustainable in view of uncertainties into the future.
Challenges in Implementing Flood Storage Areas in the Uk (PAP014738) - Full Paper
Keywords: Flood, Storage, Economic, Stakeholders, Negotiation
Subject: Land use and Floods, landslides and erosion
Abstract:
Flood storage can be defined as the temporary detention of floodwater. By capturing andstoring the flood water peak flow the extreme volume is not passed downstream to cause flood inundationbut gradually released when water levels have fallen. Flood storage has recently received greater interestat the European scale. Where the principle of flooding areas with expected lower losses (farmland)instead of high values areas (urban) is acceptable, obtaining this right on private property remains achallenge. Different forms of economic approach to obtain or incentivise this right may be considered:expropriation, one off- payment, annual single payment, and flood event losses compensation.This paper presents the results of a qualitative survey conducted in England and Wales in the frame ofthe FP7 EU EPIWATER project. England and Wales has well established flood storage and continues tobe developed as one of a number of flood risk management approaches. The research reviews thecurrent status and mechanisms that have successfully facilitated this approach. The research draws on14 interviews with a range of key stakeholders involved in implementing and managing flood storageareas. Where flood mitigation is the main issue being addressed in a locality a single payment of partialland purchase with flowage easement was found to be the dominant funding mechanism. Where greatercontrol of land use is required for predominantly environmental and conservation purposes then full landpurchase is necessary. Alternative diffuse storage approaches have also been trialled in Englandrevealing their limitations in the predictability of the final storage capacity in the catchment and their longterm sustainability in terms of maintenance which is reliant on continued contributions from AgriculturalSchemes. The UK context may be unique and not transferable to other countries. The paper furtherdiscusses this issue.
Detention Shaft for Flood Control in Bandeira Square, Rio De Janeiro - Brazil (PAP014741) - Full Paper
Keywords: Detention basin, sustainable urban drainage system
Subject: Flood risk management in mega cities
Abstract:
Bandeira Square is undoubtedly the most emblematic inundation region in Rio de Janeiro,Brazil. Every year losses achieve the amount of millions considering damage to vehicles, commerce,residences and the disruption of traffic and public services. The 2 – 10-years flood result water levelshigher than 1.5 meters in Bandeira Square. The structural solution adopted for flood control in Canal doMangue watershed were planned in the context of Rio de Janeiro Urban Drainage Masterplan – PDMAP(2013), and encompasses detention basins, channel enlargement and a diversion tunnel of Joana River.The Bandeira Square detention shaft, with its 35 meter diameter and 22 meters deep, was built during thelast year and it’s ready for operating in the next rainfall season that, in Rio de Janeiro, takes place fromOctober to March. Its concept and design criteria are presented in this paper.
Flood Estimation Using Inverse Problem Techniques Coupled to Mohid Platform (PAP014743) - Full Paper
Keywords: Watershed, Nova Friburgo, Inverse Problems, Parameters Estimation, MOHID
Subject: Urban Floods
Abstract:
In this research the MOHID Waters Modeling System is used in order to predict and analyzethe hydraulic behavior of the main rivers that constitute the Bengalas river Basin, located in NovaFriburgo – Rio de Janeiro state, which covers the most urbanized city area. For this, techniques to solveInverse Problems were used, more specifically, Luus-Jaakola (LJ) and Particle Collision (PCA)algorithms, coupled to the MOHID platform, in order to determine some of the key parameters required tomodel water bodies and their watersheds. It was used both topographic data from IBGE and also dataprovided by Nova Friburgo city hall, obtained after the preparation of the Stormwater Plan for the regionof interest. With the model calibrated and validated by experimental data it was possible to estimateflooding in this region. It is noteworthy, that this is one of the first applications of MOHID platform to modela mountain river, as well as the first use of inverse techniques coupled to MOHID Land tool. The resultswere satisfactory as an aid to decision making, based on the prevention of damage caused by elevationsof the water level that occurs frequently in Nova Friburgo and also to motivate further studies to improvethis approach.
Towards a Diversification of Flood Risk Management in Europe: a Reflection on Meta-Governance Challenges (PAP014744) - Full Paper
Keywords: Multi-layered safety, Flood Risk Governance, Flood Management, Flood Risk
Subject: Urban Floods
Abstract:
Because of climate change, extreme weather events and urban sprawl, urban regionshave to deal with increasing flood risks. It is argued, both in literature and in practice that these riskscan no longer be dealt with by focusing solely on flood defences (building dikes, dams, embankmentsetc.). Actors at various levels (international, European, national as well as regional) wish for and makeefforts at a diversification of Flood Risk Management Strategies (FRMSs). The additional role floodrisk prevention by pro-active spatial planning (building permits), flood retention, flood mitigation (e.g.urban green infrastructures, adaptive buildings), flood preparation and flood recovery can play inimproving a region’s resilience to flooding is widely debated. A diversification of FRMSs will result ingovernance challenges as existing Flood Risk Governance Arrangements (FRGAs) have to bechanged. Scientific literature so far has only addressed each shift – and the necessary institutionalpreconditions for establishing it – separately, but has failed to address them in combination.Addressing these challenges asks for an innovative vision and approach. It is however not clear underwhich conditions such an innovative vision and approach can be successful. Our paper therefore aimsto explore these conditions. It does so by presenting a research approach consisting of the four stepsof i) identifying FRMSs, ii) analyzing, iii) explaining and iv) evaluating FRGAs. The approach will beillustrated with a case study, the application of the Dutch policy concept of multi-layered safety in thecity of Dordrecht.
Integrated Coastal Flood Risk Management as a Means to Build Resilient Communities (PAP014745) - Full Paper
Keywords: coastal flood management, communities, integrated flood management, resilience, Vietnam
Subject: Flood resilient societies through community preparedness
Abstract:
There is a clear trend in the increase of damages and loss of lives and livelihoods in coastal areas as a result of rapid increase in coastal populations, and overall socio-economic development in coastal regions resulting in an increase in vulnerability of populations exposed to coastal floods and exposed infrastructure. Coastal flooding as a result of i.e. storm surges are difficult to predict and cannot be prevented, however there are means to apply integrated flood risk management approaches aiming to reduce the impact of coastal floods. A measure of the effectiveness of such approaches is the awareness and response of coastal communities to coastal flood risks. The paper introduces best practices and methods to lower coastal flood risk at the level of provinces, districts and the community level. This includes advances in coastal flood forecasting and early warning practices, improvement of institutional preparedness and integrated flood management practices as well as measures at the community level aiming to strengthen their resilience to coastal floods. The paper provides a showcase for the development and eventual implementation of a pilot project on integrated flood risk management in coastal areas in central Vietnam.
Hydrological and Meteorological Forecast Combined Systems for Flood Alerts and Reservoir Management: the Iguaçu River Basin Case (PAP014749) - Full Paper
Keywords: Flood forecasting, Reservoir Operation, Flood Control, Early warning systems, Rainfall Forecasting
Subject: Flood forecasting and early warning systems
Abstract:
Foz do Areia and Segredo hydro power plants operation may increase flooding risks atupstream União da Vitória, Porto União and Porto Vitória cities, on extreme weather conditions. Thisregion has a long past of flood vulnerability, even before 1980 when Foz do Areia was built, because itswatershed physical characteristics. Many structural and non-structural actions implemented at Iguaçuriver basin are focused on alerts of flood forecasts for local people, in addition to operation rules thatreduce impacts made by such events. Sophisticated equipments are then used for systematic water tablemeasurement at Foz do Areia and União da Vitória. Such data are inputs for a well-established real timereservoir management methodology, referred here as “water level dynamic control”, meaning to lowingdown reservoir water level at critical flood situations and preventing a worst scenario at União da Vitóriaand neighborhood. Moreover, Copel keeps a quantitative precipitation and a hydrological forecastsystems for the entire river basin, both developed by SIMEPAR, which are joint operated to provide floodsalerts at the risk sites. The Quantitative Precipitation Forecast (QPF) is obtained from high horizontalresolution (9 km) simulations of the Weather Research and Forecast (WRF) model. The hydrologicalforecast system for Iguaçu river basin, named SISPSHI, applies both automated gauge network data andQPF results to estimate river flow at 21 sites along the whole watershed. SISPSHI sets multiple forecasts,using conceptual, stochastic and probabilistic approaches, especially for União da Vitória city. Suchmethodology has provided a great improvement for flood forecasts for this place. The objective of thiswork is to demonstrate how the adoption of efficient rules for reservoir operation and the consortium ofhydro-meteorological models, as well as efficient measurements, establish essential tools for decisionmakers during extreme hydrological events.
Flood Control and Energy Production on the Brazilian Hydrothermal System (PAP014750) - Full Paper
Keywords: Flood Control, Minimum Flow, Reservoir Operation, Hydropower
Subject: Floods in a changing climate
Abstract:
The Brazilian hydrothermal system consists of 151 medium and large hydropower plants with reservoirs, including planned expansion over the next four years. About half of these reservoirs have storage capacity to regulate flows in corresponding basins, while the others are run-of-river. Thirty reservoirs provide 95% of storage capacity. There are also hundreds of smaller hydropower plants, as well as thermal and wind power plants. The hydrothermal system is completely linked in order to maximize total hydropower production while accommodating hydrological diversity among different basins. The main objective of the hydropower operation is to satisfy demand while minimizing the cost of production; in other words, maximize water use and minimize the use of fossil fuels. The system is operated not only for hydropower production but also for flood control, navigation, recreation, and water supply for various purposes. Many of the reservoirs also have storage reserved seasonally for flood control. Dams and spillways have been designed for structural safety during extreme events, such as a 10,000-year flood. The spillways, even in run-of-river reservoirs, also are used for flood control of flows with much smaller return periods, resulting in important economic and social benefits. The flood control reservations must be defined carefully in order to balance the multiple, sometimes conflicting uses of water in the reservoirs. Flood control reservations reduce storage capacity to regulate flows and affect the productivity of hydropower plants in a complex system that must be managed through integrated operation. The management also must consider changes in climate and land use, flood forecast and warning systems, as well as new data available from hydrological monitoring, etc. This paper presents a methodology to evaluate the impacts of flood control and minimum flow constraints on the electric energy production.
Environmental Assessment of Stormwater Infrastructures Built With the Best Management Practices (PAP014751) - Full Paper
Keywords: Life Cycle Assessment, flood risk management, construction, eco-efficiency, infiltration trench
Subject: Flood resilient societies through community preparedness
Abstract:
Although some infrastructures were built for environmental purposes, there is a growing concern about their actual environmental impacts. In the context of hydrologic risk management, Best Management Practices (BMPs) are compensatory techniques in urban drainage based on physical processes for the temporary storage or infiltration of stormwater. The environmental burdens taking place in the different life-cycle stages of a service, i.e., raw materials extraction, construction, transportation, use and maintenance and end-of-life can be estimated, analysed and discussed following the Life Cycle Assessment (LCA) methodology. The objective of this study is to apply LCA to quantify the environmental impacts of the implementation of new flood prevention systems, based on the BMPs. In this case, the infiltration system consists of a grass filter, swale and infiltration trench (FST) located in São Carlos (São Paulo, Brazil). After conducting the impact assessment, an estimated carbon footprint of 1.5·104 kg of CO2eq was obtained, considering a lifespan of 10 years and a runoff storage capacity of 110 m3. The main contributors to this impact are the infiltration trench and the grass layer that covers the entire surface of the system. To the authors’ knowledge, no other studies have analysed the environmental impacts of an FST from a life-cycle perspective. Therefore, future studies should work towards the assessment of the net environmental benefits (i.e., the burdens and the benefits) resulting from the implementation of this type of infrastructure.
Flood Risk Management in the State of Roraima, Amazon, Brazil (PAP014752) - Full Paper
Keywords: Risk, Flood, Management
Subject: Urban Floods
Abstract:
The Amazon region is known for its exuberant flora and fauna and its numerous watercourses belonging to the Amazon watershed, but the region as a whole suffers because of recurrent and sporadic natural phenomena such as floods . The state of Roraima was chosen as the study area due cities have heavily hit by flooding, in addition to being at risk of flooding as the capital Boa Vista. The methodology used in study this guided in document analysis by the Atlas of Natural Disasters of the State of Roraima and social data of IBGE 2010, understanding the reality by systemic method, ie designing the space from the interaction of relations political, economic and environmental, because it has the assumptions that control measures and mitigation of flood risks are still inefficient in dealing with situations of natural disaster prevention.
Lessons From Floods of 2010 in Pakistan to Help Develop Sustainable Holistic Management for the Indus River Basin (PAP014754) - Full Paper
Keywords: Indus floods, IFM, IWRM, River Restoration, Irrigation Efficiency
Subject: Floods in a changing climate
Abstract:
Pakistan is a country prone to natural hazards where dense populations in poor livingconditions are highly vulnerable to natural hazards. Events like the floods of 2010 are likely to becomemore frequent in the era of climate change, putting the human populations in the basin even moreexposed to the next inevitable disaster. Most damages in 2010 floods were exacerbated by the presenceof existing infrastructure such as major head works, flood protection levees, and unplanned ingress ofpopulation centers in the active flood zones. This study identifies challenges and recommendsapproaches for holistic flood management. Using the extent of 2010 floods derived from remote sensingdata, we identified areas of different land use impacted by floods. It was identified that large quantities ofdiversions from the river for irrigation in past 50 years have dried up many low lying areas within the rivercorridor to the extent that population centers have emerged in these agriculturally fertile, but risk proneareas. A strategy is recommended to manage the risk which shifts the focus from current practices offlood control/fighting to integrated flood management, i.e. living with the floods. The plan integrates floodmanagement and water management in the basin and calls for minimizing diversions for irrigation in orderto restore wetlands/riparian vegetation zones so that the basin‟s capacity of absorbing floods and slowingdown velocities could be reinstated. The plan recommends for an overhaul of the current inefficient floodirrigationsystem in the basin by systematically analyzing the potential of improving irrigation efficiency.The existing ageing infrastructure for water diversion and flood control could be remodeled to suit thecontemporary and future flood/water management practices. The plan could be implemented in phasesover the next 50 to 100 years.
Urban Inundation Simulation Considering Road Network and Building Configurations (PAP014755) - Full Paper
Keywords: building and road network effects, sewerage system, storm drains, urban inundation
Subject: Urban Floods
Abstract:
The main difference between rural and urban area inundation is the existence of an impermeable layer and the complexity of the road and building configuration. Therefore, although surface overland flow can be appropriately simulated by the two-dimensional diffusive model in a rural area, there also is a need for a more accurate and elaborate simulation model. In this study, we simulated homogeneous and non-homogeneous mesh types to estimate the effect of road networks and building groups. Two-dimensional run-off flow model and one-dimensional slot-model simulated ground surface run-off flow and sewer pipe flow. To connect both models, we used a newly suggested bi-directional model and its coefficients (LEE et al., 2013). The simulated results showed a non-homogeneous case could calculate more reasonable results; the results further reveal the importance of using storm drains as exchange spots in the model.
Real-Time Flood Control by Means of An Improved Mpc-Ga Algorithm and a Fast Conceptual River Model for the Demer Basin in Belgium (PAP014756) - Full Paper
Keywords: Real-time flood control, model predictive control, genetic algorithm, conceptual model
Subject: Flood forecasting and early warning systems
Abstract:
An important flood control strategy is to install large retention reservoirs in which excessive water can be stored during periods of extreme rainfall. Adjustable weirs regulate these reservoirs. To use the storage capacity of the reservoirs most efficiently, the weirs should be controlled in an optimal way. For that purpose, the technique of MPC-GA has been implemented to minimize the total damage cost in the basin. It generates several future scenarios of gate positions and selects the best scenario, based on simulation results with a conceptual river model. To improve the efficiency of the optimization, a more goal-oriented MPC-GA technique has been developed. This involves grouping of the weirs at different levels and phasing of the optimization process.
Flood Prone Areas in Santo Amaro Da Imperatriz Municipality (PAP014757) - Full Paper
Keywords: Cubatao do Sul River, Flood Mapping, HEC-RAS, Santa Catarina – Brazil
Subject: Urban Floods
Abstract:
The Santo Amaro da Imperatriz municipality (SAIM) is located in the downstream area of Cubatão do Sul river basin (CSRB) in Santa Catarina State, Brazil. Since the city has suffered with flood, the knowledge about flood prone areas in is critical for better design practices and disaster prevention plan. The objective of this paper was to analyze the changes in inundated areas due to different design rainfalls for the Santo Amaro da Imperatriz municipality. The CSRB with 740 km2 is the main drinking water supply for more than 700,000 inhabitants of the region. Water level and discharge data were obtained from 2 gauging stations: the Poço Fundo station, localized upstream of the SAIM with a 57 years historical record; and the ETA CASAN station, localized downstream of the SAIM and with a 19 years historical record. Design rainfall of 20, 50 and 100 years return period were obtained using IDF curves for the location and the SCS method. In this study we divided the total basin area in 4 subbasins: the upper reach of the Cubatão do Sul river (425 km2); the lower reach of the Cubatão do Sul river (42 km2); the Matias river basin (86 km2); and the Vargem do Braço basin (187 km2). Design flood discharge for each of the 4 selected subbasins was calculated using the Triangular Unit Hydrograph. Flood routing and inundation were calculated using the HEC-RAS model. Channel sections geometry were extracted from DEM with 30m obtained through the Epagri website. The calibration of the HEC-RAS model was done by comparison of the discharge and water level obtained with the model and the measured ones in the Poço Fundo station and the ETA CASAN station. The errors for the simulated water level were within 1% and 10% for the Poço Fundo station and the ETA CASAN station respectively. The simulated inundation areas also accurately corresponded to the neighborhoods which were reported to being flooded in past flood events. In general, the inundation behavior and inundated area found for the 20, 50 and 100 year return periods were very similar. Therefore, the 20 year return period event might be causing many of the inundations occurring in the area. In some of the downstream cross sections we observed two peaks for the water elevation due to the different arrival time of the flood wave coming from the different subbasins. Despite the reasonable results, our simulations were limited by the lack of more detailed river cross sections and for not considering some of the hydraulic structures such as bridges.
Estimated of Local Maximum Flow in Watershed of Zambeze (PAP014758) - Full Paper
Keywords: Maximum flow, Parameter estimation, Probability distributions
Subject: Floods in a changing climate
Abstract:
Information about maximum local flow is important to control and mitigate flooding in a given area or watershed or by hydraulic structures. The present study aimed to calculate the maximum flow for different return periods (2 to 10000 years) in the Zambeze watershed using probability distributions recommended in the literature. Annual natural maximum flows of a period of 58 years were used. The data were obtained at E-320 station, located in Mozambique (Tete province). To estimate the flood flows the following probability distributions were used: Log -Normal, Log - Pearson type III, generalized extreme value (GEV), Gumbel and Exponential. In order to test the fit of these distributions the Kolmogorov Simirnov test was used. The methods of L-Moments (MML) and Moments (MoM) were used to determine the parameters. The results allow to conclude that the maximum flow rate for the given return periods ranges from 5210 to 30200 mAs-1 and all distributions used were suitable for the estimation of maximum flows, however the distribution that provided the best fit was Gumbel.
New, Risk-Based Standards for Flood Protection in the Netherlands (PAP014759) - Full Paper
Keywords: risk approach, flood protection standards, Netherlands, economic efficiency, basic safety
Subject: Floods in a changing climate
Abstract:
The standards for flood protection in The Netherlands are being revised within theframework of the Delta Programme. The revision of standards includes a re-evaluation of the existingflood protection system. This flood protection system is based on so called dike rings, a set ofembankments, dunes and structures that form a closed ring. A risk approach is being adopted tostrengthen the coherence in the requirements on the flood or failure probability of various parts of theflood protection system.The new standards will better reflect the expected consequences in case of flooding due to a dike breach.This implies amongst other more differentiation in requirements on flood or failure probability of dikes andhydraulic structures (on a smaller scale than the existing rings). The height of the standards will be basedon the individual risk of becoming a victim of flooding (‘basic safety’), the societal disruption due to largescale flooding and the economic efficiency of investments in flood protection. To support the developmentof new flood protection standards both an analysis of casualty risk and a cost benefit analysis have beencarried out.The paper addresses at first the principles guiding the development of new standards. Next it isdiscussed how these principles have been operationalized making use of the methods and data of thecasualty risk and cost benefit analyses. Different principles pose different requirements; the paperdescribes how these different requirements have been integrated to obtain the provisional standardsbeing presented in this paper. Finally, the paper provides an outlook into the implementation of new floodprotection standards.
Nonstationarity of Floods in the Itajaí-Açu River, in Brazil (PAP014761) - Full Paper
Keywords: Flood frequency analysis, Peaks-over-threshold, Nonstationarity, El Niño - Southern Oscillation
Subject: Floods in a changing climate
Abstract:
Nowadays there seems to be a consensus among the scientific community that, due to climate change, there is an intensification of the hydrological cycle, which, coupled with evidence of the impact of persistent modes of regional climate variability, have led hydrologists to study hydrological extremes under nonstationarity. In this paper, the peaks-over-threshold (POT) model with Poisson arrivals and generalized Pareto (GP) distributed exceedances is used to assess the influence of El-Niño Southern Oscillation (ENSO) and other climate indices in the flood regime of the Itajaí-Açu river, in Southern Brazil. The application of the POT approach has the advantage of being able to detect and model the influence of climate on the occurrence process of floods and their peak magnitudes separately.
Exploring Strategies of Lid-Bmps for Land Subsidence Runoff Control: the Case Yunlin,Taiwan (PAP014762) - Full Paper
Keywords: Land subsidence, Low impact development, Stormwater best management practices, Storm water Management model
Subject: Land use and Floods, landslides and erosion
Abstract:
In this paper, a planning analysis of implementing low impact development (LID) type of stormwater best management practices (BMPs) for land subsidence area runoff control is presented. A case study is the Yunlin Kouhu Township (YKT) in Taiwan. BMP is a best management practice (BMP) planning and analysis tool, which is capable of simulating BMP performance BMP placement and design. The Storm Water Management Model (SWMM) was used to simulate LID-BMPS for the YKT. Optimization analysis for BMP design aimed at achieving either runoff control was then conducted. The results were used to form recommendations to the YKT for modifying the present stormwater management system in order to achieve more runoff control strategies. The YKT strategies of stormwater system incorporated some LID BMPs such as green roofs, porous pavements and rainwater cisterns.
Pearl - Preparing for Extreme and Rare Events in Coastal Regions (PAP014763) - Full Paper
Keywords: Coastal Flood Management, Holistic Risk Assessment
Subject: Floods in a changing climate
Abstract:
Coastal floods are regarded as one of the most dangerous and harmful of all natural disasters. Rapid urbanization in coastal areas combined with climate change and poor governance can lead to a significant increase in the risk of local pluvial flooding coinciding with high water levels in rivers and high tide or storm surges from the sea, posing a greater risk of devastation in coastal communities.There is a need to improve forecasting, prediction and early warning capabilities using state of art science and technology to help policy makers and emergency services to develop robust risk reduction strategies. However, forecasting and prediction is only part of the answer. Of equal importance is the ability to effectively warn the population in areas that will be affected. All warning systems feature multiple lines of communication enabling emergency messages to be sent to the emergency and rescue services, as well as to warning systems for the general public. For such systems to be effective, it is essential that they are integrated into broader management strategies and supported by appropriate institutional and organizational arrangements. Therefore, preparing for effective response to extreme events not only involves technology but also significantly social, economic, organizational and political considerations. Currently there is a clear indication of a lack of interaction between social aspects and technical measures and this appears to be a major hindrance for solving some of the greatest problems associated with floods and flood-related disasters.To overcome these shortcomings, and based on the belief that problems are best solved by attempting to correct or eliminate root causes, as opposed to merely addressing the immediately obvious symptoms, the PEARL project aims at developing adaptive risk management strategies for coastal communities focusing on extreme hydro-meteorological events, with a multidisciplinary approach integrating social, environmental and technical research and innovation. It takes the holistic view of risk as an essentially sociotechnical problem which concerns not only technology but also our values and our beliefs.
Geographical Damage Survey (Geodamsur) (PAP014767) - Full Paper
Keywords: Flood Management, SIG
Subject: Urban Floods
Abstract:
The quality of life of the people affected by flooding may be decreased due to this type of threat and need to have a system to record the damage caused by the disaster to restore the lives of those affected. For this it is necessary to know the damage to the homes in which these people live, in which they may have been evacuated because of the unfavorable conditions found after the disaster. Also it is necessary to register the losses that occurred in the productive activities of people, as well as damage to health. In this paper, we introduce the GEODAMSUR system, an implementation of a prototype of a geographic information system, allowing the entry of the data gathered in the recovery phase. The system provides a mobile interface to accomplish the damages survey and all the information gathered is centralized in a main System which allows the display of the damages presented in form of tabular data and maps. GEODAMSUR is integrated with other systems such as flood forecasting and early warning systems to perform different types of analysis of this data to help in the decision making.
Generating Precipitation Ensembles for Flood Alert and Risk Management (PAP014770) - Full Paper
Keywords: uncertainties, precipitation ensembles, flash flood
Subject: Flood forecasting and early warning systems
Abstract:
Precipitation fields are crucial for hydrological forecasting. A forecasting system comprising a rainfall-runoff model uses observed and forecast precipitation to forecast discharges several hours to days ahead, which will be used for flood alert and risk management. Many sources of uncertainty play a role in a hydrological forecasting system, including uncertainties coming from the observed precipitation fields used as input data. One approach to take into account these uncertainties is to generate an ensemble of possible scenarios of observed precipitation. The aim of this study is to create an ensemble of precipitation fields merging information from rainfall radar and rain gauges. To do that, the turning bands method (TBM) adapted by Leblois and Creutin (2013) is applied in a new manner, eg with: 1) the generator parameters estimated from radar rainfall fields and 2) the generated fields conditioned on precipitation data measured by rain gauges. The case of a rainfall event observed in the Var region (southeastern France) is used to illustrate the method. Results show that ensemble simulation experiments conditioned on point measurements can be useful to quantify the uncertainties of precipitation fields observed by rain gauges. The proposed method could be a solution to merge radar and rain gauges information, while quantifying the observed precipitations uncertainties.
Zoning for the Management of Urban Flood Risk and Riparian in Canton Samborondon by Effect of Sedimentation in Babahoyo River and Extraordinary Weather Events (PAP014771) - Full Paper
Keywords: Geomorphology, Urban Flooding, Riverside Flooding
Subject: Floods in a changing climate
Abstract:
Samborondón has a very high population growth rate; causing an increased urban development, pavement works and the reduction of the green areas, regarding the construction areas, producing a remarkable increase of the stormwater drainage, wich is conducted through hydraulics structures up to its final discharge in channels, estuaries or simply dumping it into the Babahoyo or Daule rivers. Babahoyo river geomorphology has provided information about islets due to the sediments buildup on its cause, because of the basin contribution, erosion and because of the tides entering the gulf. The present of this sediments inside the river cause, influences on the storm sewer system discharge levels; many times, causing its collapse and small floods, wich like the channels discharging directly into the river, have a backwater effect at the exact moment of discharge. This investigation, aims to zoning urban and riverside areas, which are more likely to be flooded, control and discipline urban occupation through a compatible densification according to the flood risks; in order to avoid urban areas hydrograph increment and to suggest possible theoretical solutions using hydraulic modeling samples.
Study on Probabilistic Disaster Risk Assessment and Management (PAP014773) - Full Paper
Keywords: disaster risk, hazard probability, probabilistic risk assessment, safety level, disaster management
Subject: Flood risk management in mega cities
Abstract:
This paper proposes a new concept of Probabilistic Approach in disaster risk assessmentand management that could flexibly adapt the risk reduction plans and measures against intensifyingscale of disaster. The concept, in contrast to the previous method based on a deterministic scenario ofdisaster, was conceived from lessons of recent disasters including extreme events that reminded us theimportance of prospecting society’s safety in which it can inclusively target any probable scale of naturalphenomena.The previous method of disaster risk reduction, which in this study is denoted as the deterministicscenario based approach, proved that there are remaining challenges, for example in sharing truthfulinformation about extreme risk and its probability among local societies and communities.The new approach with probabilistic risk assessment should then provide risk managers with reliablemethodology of how to secure the local security level and how to plan the countermeasures consideringthe development policy of the local area, estimated future damage, cost effectiveness of disasterreduction investment, financial capacity of the society, robustness of the planned options, acceptability ofthe measures by community and other priority aspects such as poverty reduction and vulnerable peoplesprotection.For the first step, a new concept is created to consider multiple disaster scenarios including return periodand hazard scale which is necessary to set the target security level and select the appropriate optionswith their available financial and human resources. In the approach, we set the category of impactassessment based on wide range of hazard projection and adaptive planning with multiple scenarioselections, and then prospect the total image of disaster risk reduction in every scale of impact, using theprobability of each hazard. This approach enables to create strategic combination of structural and nonstructuralmeasures under redundant cooperation by various sectors including socio-economicdevelopment and infrastructures.
Pluvial Flooding in Santo André City - São Paulo: Observation and Prediction (PAP014774) - Full Paper
Keywords: Pluvial Flooding, Tamanduateí River, extreme rainfall
Subject: Urban Floods
Abstract:
The goal of this paper is to analyze the pluvial flooding that occurs in Santo André region caused by extreme rainfall as well as to propose a statistical model for rainfall flood forecasting. Santo André being located in the São Paulo metropolitan area, it has developed in the floodplains of the Tamanduateí River, and for this reason it has a history of recurrent floods. In this study, three points of the highest frequency of flooding were selected: the river Tamanduateí and its tributaries Meninos and Oratório. The dataset includes daily rainfall data of three rain gauges closest to the rivers. So we carried out a statistical analysis involving the accumulated daily rainfall with flood records on the three rivers. On the other hand, multi-linear regression (MLR) approach is used to construct the daily extreme rainfall prediction model. The results showed that the highest frequency of rains and flooding occurs in the months of January and February with an average of 2 flood events in January. The floods identified as extreme by the number of affected districts occurred in 15 December 2011, where the rainfall intensity exceeded the daily value of 120 mm. On the other hand, the higher frequency of flood events was associated with the overflow of the river Tamanduateí followed by that of Meninos. The maximum daily rainfall associated with these events reached values of 152 mm. In addition, it was confirmed that the rains, both in their mean values, as in their extremes, have increased. The MLR model showed difficulty in capturing the peaks of extreme rainfall that cause floods, underestimating their value. We believe that the MLR model cannot follow the inherent non-linearity of rain. However, the best prediction model was found for the river Meninos, where the model followed the variability of daily rainfall.
Flash Flood Forecasting Using Weather Radar and Satellite Data for Urban Catchment in Rio De Janeiro (PAP014783) - Full Paper
Keywords: Distributed Hydrological Modeling, Nowcasting, Remote Sensing of Clouds, Meteorology, Hydrometerology
Subject: Flood forecasting and early warning systems
Abstract:
According to the World Meteorological Organization, flash floods are the most lethal form of natural hazard (based upon the ratio of fatalities to people affected), and cause millions of dollars in property damage every year. This type of hydrometeorological disaster depends on land surface and atmospheric specifics conditions. A combination of a high rainfall rate with rapid and often efficient runoff production process is common to most events. In Brazil, flash floods can be deadly. Recently in January 2011, landslides, debris flow and flash flood processes in the mountainous region of Rio de Janeiro caused more than 900 fatal victims. During 3 days, the rainfall achieved almost 400 mm, a rate 71% higher than the month average. Despite the significance of these events, few countries in the world have already implemented flash flood warning systems. This is due in part to the technical complexity of predicting extreme events with enough confidence and lead time to take precautionary action. Since flash floods processes happen in the same temporal and spatial scale of severe storms, this paper aims to provide analyses of case studies simulating real-time flash flood forecasting, with high resolution weather radar and satellite rainfall estimates in an urban catchment in Nova Friburgo, Rio de Janeiro. Results indicate that at least some of flash floods can be predicted by the physically based distributed hydrologic modeling, even for shot-lived events on small catchments. Based on the limited observations available, validation indicates that there is good agreement of rising limb of hydrograph between simulated peak discharge and peak discharge observed. This technique has been developed by the Brazilian Centre for Monitoring and Warnings of Natural Disaster (Cemaden) and will be tested in operational environment for pilot catchments in following rainy season, improving flash floods early warnings in Brazil.
Physical Deterioration of Quality and Soil and Water in Your Connection Mass Removals (PAP014785) - Full Paper
Keywords: urban areas, slope, soil density, waterproofing, changes
Subject: Land use and Floods, landslides and erosion
Abstract:
The physical behavior of the soil and water based their management practices, especially in the strong slopes. The objective of this research was to evaluate the interrelationships between soil physical properties and water holding capacity of soils on different systems for urban use of San Juan de Pasto - Colombia and its impact on processes of mass removal. In 2013, we selected four areas contained in different slopes, which were built and are almost entirely urbanized twenty years ago, in two more places there is some kind of vegetation. Twenty seven soil samples were collected in the layers 0-45 cm, 45-100 cm and 100-145 cm depth, the resulting data determined as a result of water retention curves (WRCs), of soil in different seasons, which served to make correlations with variables such as bulk density, organic carbon content and clay content. It was found that the sealing of land use for asphalt roofing, resulted in higher values of soil density and soil with some vegetation cover type even at high slopes, resulted in lower bulk density, lower carbon organic and clay. Some canonical variables indicated dependence on moisture content of the soil density. The changes in the curves of water retention in the soil suggest a greater compaction of soils in areas with strong slopes, plus also mean a deterioration of physical and water of this quality, contributing to the increased likelihood of moving large amounts of land in a high slope slip.
Climate Change and Floods in Paraná River Basin (PAP014788) - Full Paper
Keywords: Climate Change, Maximum Discharge, Regional Climate Model
Subject: Floods in a changing climate
Abstract:
The Paraná River basin is a major river system in Latin America, with a total area of approximately 800.000 km², it is situated over six Brazilian states (Minas Gerais, São Paulo, Goiás, Mato Grosso do Sul, Paraná and Distrito Federal), being especially important for hydropower generation (including Itaipu dam), agriculture, and human water supply. These water resources uses depends on the rivers and climate issues at the basin. Therefore for better water resources management it is important the knowledge of hydrological processes and its possible responses to climate changes. This study presents the use of the MGB-IPH distributed hydrological model to assess the impact of climate changes on extreme streamflow (floods) for several control points across the Paraná River basin. Projections of temperature and precipitation, from the ETA40 Regional Climate Model (RCM), under A1B emission scenario, were used to run the hydrological model. The simulated annual maximum discharges were analyzed throughout four 30-year's time-slices (1960-1990, 2011-2040, 2041-2070 and 2071-2100). Results indicate that for most analyzed points the climate projections results in an increase of simulated maximum floods. However considerable variations are showed by different model members, return periods, and basins locations. Considerations are made about uncertainties associated with data and employed methods.
Needs for Adaptation of Urban Flood Management Under Climate Change (PAP014791) - Full Paper
Keywords: Adaptive strategies, climate change, integrated flood management, urban flooding
Subject: Floods in a changing climate
Abstract:
The problems posed by urban flooding are difficult to confront and manage. Urban centres already comprise over 50% of the total population worldwide and, according to the United Nations, this number is projected to rise to 70% by 2050. The combination of climate change, increasing urbanization, demands for housing and industrial land, and economic development cannot be discounted in urban flood management. The past may no longer be a reliable guide to the future, which particularly concerns urban flood management planning and implementation. Rather than focusing on any one of these issues or one single measure, it is necessary to combine them into a comprehensive planning process. This process requires flexibility and regular validation in order to increase adaptation and enhance community resilience.The paper examines the key elements of effective urban flood management through the lens of climate change. Addressing these key elements requires an integrated approach that aims to "live with floods" and empower participation of various stakeholders involved in flood management. The paper discusses the major issues and aspects of both urban flood management and climate change adaptation likely to have a significant impact on urban planning. It also explores how current policies, planning and implementation mechanisms can be assessed and evaluated. The paper attempts to answer the question: is the current urban flood management model effective within the context of climate change? Two case studies will showcase and illustrate the application and management of such integrated strategies.
Quality Analysis of Probabilistic Hydrological Forecasts (PAP014794) - Full Paper
Keywords: decision making, uncertainty of forecasts, quality indices
Subject: Flood forecasting and early warning systems
Abstract:
Aiming at optimizing power generation and the increased reliability of flood warningsystems, decision makers are searching for hydrological models which are more accurate andrepresentative. Probabilistic models consider the uncertainty of forecasts, therefore they are more faithfulto the randomness of hydrological phenomena and more transparent with respect to the uncertainties ofthe forecast. However, there are still difficulties in the direct quantification of the quality of these type ofmodel. Katz and Murphy (1997) propose the analysis of forecasts’ sharpness and discrimination. Both arebased on the concepts of climatological probability. The first is the forecast variability and the secondrelates the predictions overall average given a certain observation. In order to assess the predictionreliability, Jolliffe and Stephenson (2003) use a frequency histogram of the observation occurrences ineach ensemble of forecast probability distribution. This work presents a method of accounting for thesethree quality indices. Moreover, they are simultaneously assessed following the concept of multi criteria toquantify the quality of probabilistic hydrological forecasts. Two probabilistic models were developed andoperated by the Technological Institute SIMEPAR, Paraná, Brazil. One is based on the Bayesian theoryand SOM neural network; the other is based on historical errors of deterministic forecasts and Meta-Gaussian transformation. The indices allow the monitoring of forecasts’ quality of both models and thecomparison to confirm which one has the best results.
Effectiveness and Reliability Analysis of Emergency Measures for Flood Prevention (PAP014796) - Full Paper
Keywords: Emergency measures, Flood Reliability analysis, Risk
Subject: Flood risk management in mega cities
Abstract:
During flood events emergency measures are used to prevent breaches in flood defences. However, there is still limited insight in their reliability and effectiveness. The objective of this paper is to develop a method to determine the reliability and effectiveness of emergency measures for flood defences. The investigation is focused on measures that prevent breaching of a flood defence in a river system; measures to limit and/or close breaches are beyond the scope.To determine the failure probability of flood defences with emergency measures two assessments are made: 1) the reliability of implantation of emergency measures is determined and 2) the effect of the implemented emergency measures on the reliability of the flood defence. For an emergency measure to function correctly three phases need to be passed successfully: ‘Detection’, where weak spots in the flood defence are detected, ‘Placement’, where emergency measures are built on time, and ‘Construction’, which is the successful functioning of the emergency measures.The reliability of ‘Detection’ and ‘Placement’ depends on human and organizational reliability and the feasibility of complete placement of the measures within the available time. The reliability of the ‘Construction’ concerns the structural performance of the emergency measure. For a case study along a part of a river in the Netherlands a failure probability of emergency measures for the piping failure mechanism is estimated to be 1/3 per event. The human / organizational reliability during ‘Detection’ and ‘Placement’ proved to be dominant. When translated to dike ring level the failure probability is reduced with about a factor 2. This is largely explained by the length effect: with increasing amounts of weak spots in a flood defence the contribution of emergency measures will decrease.
Baquirivú River Floodplain Park, Brazil (PAP014799) - Full Paper
Keywords: Detention basin, floodplain park, sustainable urban drainage system
Subject: Flood risk management in mega cities
Abstract:
Metropolitan Region of São Paulo (MRSP) is a dense urbanized area with recurrent floodingproblems on this main watershed because its drainage system complexity. In Baquirivú Guaçú RiverBasin, one of priorities and most vulnerable watershed, an important flood control system based onSUDS principles was designed. This system is composed by a 20 km channel, five detention basins, afloodplain park along all main stream and reservoirs and a new 10 km road. After this intervention, it’sexpected to reduce flood risk significantly, to preserve and protect floodplain areas and create newspaces for population leisure. In a second stage, it is expected that authorities work on water qualityimprovement to complete the implementation of an integral solution for regional urban drainage.
Operational Flood Forecasting System to the Uruguay River Basin Using the Hydrological Model Mgb-Iph (PAP014801) - Full Paper
Keywords: Flood forecasting, Hydrological Modeling, Uruguay River
Subject: Flood forecasting and early warning systems
Abstract:
Operational hydrological forecasting systems are very valuable tools for disasters prevention, such as floods. These systems are especially important for basins that have a fast runoff component and no well-defined seasonality, which is the case of most river basins in the south of Brazil. Focusing this study cases, we present the development and up-to-date results of an operational flood forecasting system to the Uruguai river basin, located in Santa Catarina and Rio Grande do Sul states, Brazil. The forecasting system is based on the MGB-IPH large scale hydrological model, and works with hourly time step. The system operates alone automatically generating experimental deterministic forecasts at some locations in the Uruguai river basin and results are automatically disposed in the internet everyday (www.ufrgs.br/lsh). We present the model forecasting results for the main floods that occurred since the system operation begin on July, 2013. This result show a good accordance with observed flows, but also motivates the research for more improvement, such as the addition of ensemble rainfall forecasts into the system.
Flood Risk Management by Public and Private Agents in the Coastal City of Lagos (PAP014805) - Full Paper
Author(s): Ibidun Adelekan
Keywords: Flood Risk, Flood Management, Public and Private Agents, Lagos
Subject: Flood risk management in mega cities
Abstract:
Lagos, West Africa's foremost port city is projected to rank the third largest global megacity with an estimated population of 23.2 million in 2015 according to a report of the UN World Urbanization Prospects. An increasingly important environmental threat to the city's high population and large concentration of residential, industrial, commercial and urban infrastructure systems is coastal and urban flooding due to climate change and sea level rise. The rapid rate of urban development with the attendant environmental problems is a further driver of flooding in the city. Over the past decade, flood risks has increased significantly affecting key sectors of the urban system as well as impacting on all social society. The paper presents findings of an on-going research project which employs a mix of quantitative and qualitative methods to examine the multiple approaches to flood risk management by public and private agents in the city. Community-based flood protection measures adopted by different socio-economic groups as well as the factors that influence flood management decisions are also discussed.
Integration of Information Technology Systems for Flood Forecasting With Hybrid Data Sources (PAP014807) - Full Paper
Keywords: Flood forecasting, WSN, VGI, SWMM
Subject: Flood forecasting and early warning systems
Abstract:
This paper presents a new methodology for flood forecasting integrating volunteered geographic information – VGI and wireless sensor networks – WSN. The methodology was applied to São Carlos city urban basin, São Paulo state, Brazil and showed promising results compared to the forecasted ones using only sensor data. The major contribution of this methodology is the high capacity of adaptation to different kinds of data, increasing the amount of data and reducing the forecasting uncertainty. Also, the proposed methodology can simulate scenarios of predicted precipitation using weather radar and two other methods - Precipitation forecasting using weather data and forecasting using statistics techniques. This work is still under development and the main objective of this paper is to present the current status of the research and the proposed methodology. The preliminary results showed that the basin model still needs improvements before conducting calibration.
Determination of Intensity-Duration-Frequency Equations for Pernambuco State Mesoregions Through Disaggregation Method (PAP014808) - Full Paper
Keywords: high intensity rainfall, Pernambuco, disaggregation method
Subject: Urban Floods
Abstract:
The knowledge of high intensity rainfall patterns is extremely important due to its application in hydraulic engineering projects. The difficulty in obtaining intensity-duration-frequency equations through pluviographs because of the poor density of pluviographs network has led engineers to use other methods for determining these equations from pluviometric records. In this paper were used time series from 8 municipalities of mesoregions of Pernambuco State to determine intensity-duration-frequency equations using rainfall disaggregation method. The goodness of fit Gumbel distribution was confirmed by the Kolmogorov-Smirnov test with a significance level of 5%. The generated equations showed reasonable fitting with R² ranging from 97,5% to 97,9% for the rainfall disaggregation method.
Point to Area Rainfall Relationships Using Radar Data (PAP014809) - Full Paper
Keywords: Point to Area, Radar, Hydrology
Subject: Urban Floods
Abstract:
Point to area rainfall relationships are useful in drainage systems planning and design, especiallywhen lumped simulation tools are applied or distributed rainfall patterns are not available in the studyareas. In order to proper evaluate and consider the effective spatial distribution, several different pointto area relations have been used over the world, including famous US Weather Bureau`s and Miller`srelations, based on the conventional rainfall records and considering frequency, surface area andstorm duration dependence. In the last 10 years new relations were constructed using radar data,after the benefits of this spatial high resolution monitoring technique. This article presents thedevelopment of a point to area relation considering the last 10 years of radar monitoring in the upperpart of Tiete River basin where the city of Sao Paulo (Brazil) is located, addressing different goalssuch as drainage system assessment and scenarios modelling.Sao Paulo meteorological radar tracks a 250km radio area producing rainfall maps at 3.000mconstant altitude (CAPPI) each ten minutes. These data area consisted and correlated with a groundstations network and stored in ascgrid files with 2 x 2 km spatial resolution. Using an algorithm toselect rectangular surface averaged rainfall from 50 to 2500 km² and durations from 1 to 24 hourscurves where produced and adjusted to reflect point to area reduction factor as functions of thesurface area and duration. Resulting values where combined to regional IDF relationship establishedafter long time series station in the basin, in order to associated return periods. Resultant curveswhere compared to traditional ones and other relations established with radar data.
Development of a Snowmelt-Runoff Model Considering Dam Function for the Ane River Dam Basin, Japan (PAP014812) - Full Paper
Keywords: Ane River Dam, distributed hydrological model, Snowmelt, SVAT
Subject: Floods in a changing climate
Abstract:
The Ane River Basin is located in Japan and snowmelt during spring is a major contributionto total river discharge. The proper estimation of the snowmelt runoff in the maritime snow area isnecessary for the understanding of the hydrological processes of the region and for analyzing differentclimate change impacts in the water resources of the area. The objective of this paper was to developand test an energy balance snowmelt and runoff model for the Ane River Dam catchment consideringdam reservoir. The Ane River Dam (ARD) has a catchment area of 28 km2 mainly covered by forest. Themodel developed was a combination of three different models: an energy-balance Soil-Vegetation-Atmosphere-Transfer model for the snowmelt calculation; a cell distributed runoff model (CDRMV3); andthe implementation of a dam reservoir routing routine using the Level Pool method. In the model we setthe grid cell where the dam is located to have the reservoir rules. The runoff model was calibrated byusing dam inflow hydrographs for three summer events. Snow accumulation and depletion patternrepresented well the observed snow depth at the crest of the ARD. The total snow depth wasoverestimated due to the constant snow density which was used in the model. The time of snowdisappearance was well estimated for the winter of 2010-2011, however, it was 10 days late in the winterof 2010. The simulated peak outflow from the dam was overestimated but the recession curves wereaccurate. The use of the summer calibrated parameters for the three winter events demonstrates thedeveloped snowmelt-runoff model sensitivity to snowmelt and rainfall. However, there are still verificationlimitations due to the quality of observed inflow data during the winter and the uncertain simulation of soilmoisture patterns.
Evaluation of the Contribution of Riparian Vegetation in Reducing Surface Flow and Water Quality in Urban Watershed (PAP014815) - Full Paper
Keywords: Riparian Vegetation, Water Quality, Surface Flow, Urban Rivers, Payment for Environmental Services
Subject: Land use and Floods, landslides and erosion
Abstract:
The urban planning focused on environmental issues is a challenge for large urban centers and is becoming increasingly a trend of public planners. Currently, is possible to notice in Brazil that cities are growing without an efficient urban and environmental model of planning, areas considered at risk are being occupied indiscriminately, laws of land use being disobeyed, including river banks, resulting in degradation of riparian vegetation. This kind of vegetation is associated with the water bodies, forming long corridors that have functions as: erosion control, water filtration, flood control, increased biodiversity and contribute to the landscape harmony. With perceptive evaluation of orthophotos obtained in this work it was possible to evaluate the gradual development of riparian vegetation over twenty-five years at a stretch that belongs to the Belém River Basin in Curitiba-PR - BR, this is an urbanized watershed. Concluded that the method used by the riparian vegetation caused a considerable effect on some water quality parameters, as well as collaborating with the containment of floods. Increased water quality and benefits in relation to drainage would be maximized if the riparian vegetation extended along the basin, characterized as an important environmental service and reducing the impact of heavy rainfall in urban areas. Payment for Environmental Services - PES can be seen as an incentive to maintain riparian basins not only in rural but also in urban watersheds, where the impacts of a full cause major damage due to population density.
A Participatory and Integrated Flood Risk Management Experience: Belo Horizonte, Brazil (PAP014817) - Full Paper
Keywords: Flood Risk, Integrated Flood Risk Management, Civil Defense, Community Mobilization initiatives
Subject: Flood resilient societies through community preparedness
Abstract:
Floods are one of the most destructive disasters that occur in the city of Belo Horizonte, located in the southeastern region of Brazil. Between the years of 1991 and 2010, these processes caused dozens of deaths in the municipality, affecting nearly 300,000 people. In order to mitigate those losses, the Belo Horizonte city government adopted a systemic risk management approach. In this sense, structural and non-structural measures were implemented, with a strong focus in community involvement, which helps to increase the resilience and improve the local understanding of flood risk. These measures are internationally recognized and, due to its efficiency and applicability, should serve as an example for other municipalities. Therefore, the objective of this study is to describe the community mobilization initiatives conducted by the Belo Horizonte municipal government, with a special emphasis on risk prevention and in flood emergency response. Furthermore, this study aims to reflect about the risk management system employed, with regards to the advances provided by these measures, as well as their challenges and difficulties. For this purpose, technical visits were performed at different departments and offices of the city. Those visits were coordinated by the Municipal Civil Defense Council (COMDEC-BH). One of the most relevant preventive action identified was the continuous training and mobilization of the population that lives in flood prone areas, through the Centers for Rain Warning and Alerts (Núcleos de Alerta de Chuva - NAC). These centers are composed by government officials and community members who volunteer their time. They allow the establishment of a direct channel of dialogue with the people affected by floods, which improves the inhabitant's perception of risk and the effectiveness of disasters response and recovery. Until the year 2013, 42 NACs were established, with approximately 350 trained volunteers who act as agents on the alert and emergency warning of other residents. The risk perception and knowledge of the NAC's volunteers aims, among other activities, to identify and improve escape routes, define temporary shelters and propose simple interventions to mitigate the risk. In addition, the residents develop participatory flood hazard maps, commonly called as "spoken floodplain maps" (mapas de mancha falada), which reflect the local reality, witnessed by the community in past flood events. Since the implementation of these measures and due to the better flood preparedness of the population there was a significant decrease in the quantity of people affected by floods and in its losses. The major factor that contributes to this success is the application of social technologies that include and expand the participation of vulnerable communities both in knowledge of the problems and in finding out solutions. Another important factor is the constant interaction of the departments of the city government in the risk management, which should be encouraged and pursued by other municipalities. Thus, Belo Horizonte has achieved a reduction of vulnerability and is becoming a safer city for its inhabitants.
Analysis of the Uncertainty Associated With Numerical Schemes in Flood Inundation Models (PAP014819) - Full Paper
Keywords: uncertainty, modelling, urban
Subject: Urban Floods
Abstract:
Recent evaluations of 2D models have focused on benchmarking computer codes and analysis of model outputs with respect to model inputs, focusing on the model as a black box, in order to understand sources of input uncertainty and how they propagate through to results. In this work, the influence of the numerical representation of the model on the results and the associated uncertainty is evaluated in a systematic way. For a test case of a canal embankment outburst event in Coventry the LISFLOOD code, which contains modules within the framework with different levels of physical representation, is tested against a range of uncertain inputs that are typically considered in a modeling exercise. The analysis is extended to show how traditional evaluation techniques such a comparison of extent do not capture the full uncertainty range of the modules. Instead, the use of risk based methods, in this case a cost of damage model shows how local variations in model results are rarely captured in measures of extents, but can be enhanced with exposure based methods. Overall, the level of physical representation is shown to be critical to model results.
Sacramento Model Calibration Using Different Methodologies - Application to the Itabapoana-Mg River Basin (PAP014820) - Full Paper
Keywords: Flood Management, Sacramento Model, Calibration methodologies, SOBEK, RRL
Subject: Urban Floods
Abstract:
Despite the considerable progresses in computational hydraulics the calibration of hydrological models still requires a meticulous and laborious effort. However, the development of model calibration supporting tools has facilitated that work and improved the obtained results. The objective of this paper, developed under a R&D project, is to evaluate the performance achieved by using different calibration techniques for the Sacramento rainfall-runoff model of the Itabapoana-MG river basin. Bom Jesus do Itabapoana, a flood prone city, is located about 35 km downstream of Rosal hydropower plant. The limited capacity of Rosal reservoir implies that it cannot be used to mitigate flooding at downstream cities. However, flood forecasting can be used to avoid potential downstream damages and support decision making to defend and mitigate the undesirable effects. There should be a balance between the models performance and their computational times. It is important consider sufficiently precise results for sound decision-making outcomes, as well as results fast enough to be used in an operational decision support system environment. SOBEK software was chosen for prediction of flood events and Sacramento hydrological model was selected as rainfall- runoff model. SOBEK does not offer a module for automatic calibration of their hydrological models. Thus, for the quantification of Sacramento parameters, it is possible to make use of external algorithms for automatic calibration based on global optimization techniques. This paper assesses the eficiency of using automatic calibration results using the Rainfall Runoff Library (RRL) within SOBEK hydrological module. In general, the results for RRL were better than the ones reached by SOBEK. Despite differences, the use of RRL as a tool to accelerate the parameters determination process for the Sacramento model has obtained satisfactory results within SOBEK.
Urban Floods: Models Used in Brazil (PAP014823) - Full Paper
Keywords: urban floods in Brazil, computational modeling, efficiency of the methods
Subject: Urban Floods
Abstract:
Brazil has been faced with many problems regarding urban floods. In order to predict and prevent the devastating impacts that these events might have on society many computer models have been used in the past decades. The main objective of this work was to do a literature review of the models used in Brazil for urban floods. We surveyed data found in Brazilian literature, using only virtual bases. We finally selected fifteen papers written in Portuguese and analyzed their results and coefficients of efficiency. Most papers were published in the Revista Brasileira de Recursos Hídricos after the year 2000, and there were 15 different models used. We could illustrate the models and their applications in Brazil, however there were few papers in Portuguese and we should expand our search to include the works published in international journals as well.
Integrated Flood Management (Ifm) Strategies for a Tidal River Basin: a Case Study of Tutong River Basin Development in Brunei Darussalam (PAP014826) - Full Paper
Keywords: IFM, IWRM, flood flow, residual flood flow, public participation
Subject: Land use and Floods, landslides and erosion
Abstract:
Integrated Flood Management (IFM) aims at sustainable development under the risks offlooding minimizing loss of life and property, maximizing the efficient use of flood plains, using theresidual flood flows for irrigation and leaching and restoring and maintaining river health and associatedeco-system and environment. Tidal nature of a river adds yet another dimension/parameter to it forintegration of soil and water quality and quantity issues required for sustainable irrigated agriculture andagro-industry. Traditional flood management is a short-sighted mono-disciplinary 1D model approachhaving persisting shortcomings. In its practice in Tutong river basin, traditional flood management onlyfocusses on how to quickly get rid of the flood flow. The ever increasing and emerging new challengesrequire a multi-disciplinary approach of IFM adoption. River Tutong can be termed as a tidal estuaryhaving salt water intrusion affecting some 25 kilometers in the basin hinterland and severely affectingagriculture and waterworks. There is plenty of rainfall in the basin almost round the year, yet rain-fedpaddy and other crops do suffer for lack of water in between the rainfall events. Farmers have abandonedagriculture from the otherwise arable lands that require irrigation water of quality and quantity from theriver. The IFM for the Tutong river basin requires special attention of more of a Integrated WaterResources Management (IWRM) approach. This paper reviews and attaches special attention to redrawthe traditional stand-alone approach of flood management for Tutong river to be remodeled into anelaborate and effective IFM suitable for Tutong River Basin (TRB). Besides the normal flood disaster,preparedness and proofing events, it would also address the socio-economic, environmental, land andwater development, navigation, aquaculture and eco-system issues pertaining to basin developmentincluding public participation. The Tutong river IFM pre-feasibility study recommends that a major tidalsluice may be built at or near the confluence to the sea with adequate flood flow passage. Coupled withIWRM approach the flood water management in the basin should include peak flood flow passage forflood mitigation, on-stream storage of residual flood flows for compartmentalization and irrigatedagriculture. The use of the residual flood flow for irrigation and waterworks can be achieved by on-streamstorage and controlled release of flood flow. Infrastructure development, institutional management withpublic participation and construction and operation of control sluices at strategic locations would play avital role for overall success of the basin development. Tutong river that appears to be a sorrow of thebasin could potentially be converted into a basin of joy.
Participation in Flood Risk Management and the Potential of Citizen Observatories: a Governance Analysis (PAP014829) - Full Paper
Keywords: Flood risk management, participation, innovation, decision making, citizen observatory
Subject: Flood resilient societies through community preparedness
Abstract:
The implementation of the European Flood Directive 2007/60/EC requires the establishment of public participation mechanisms to ensure citizens’ involvement in the flood management cycle. This raises questions on how to achieve this goal and successfully translate the directive into meaningful and effective participation. Innovative means, such as citizen observatories enabled by information and communication technologies, have the potential to provide new ways of participation. In this paper, we undertake a comparative analysis of governance structures, institutions and mechanisms for citizen participation in the UK, the Netherlands and Italy and analyze the transposition of the directive in these different contexts. Empirical and desk research in the three case study areas was undertaken, covering local water authorities, environmental protection agencies, emergency services, local stakeholders, and their roles and interactions with citizens during different phases of the disaster cycle. Our analysis of the transposition of legal obligations for citizen participation shows that implementation is limited when examining in detail a) the respective roles and types of interactions between citizen and authorities and b) the impact of citizen participation on decision making. Different authorities have differing perceptions of citizen participation in flood risk management in terms of their roles and influence. Our results also indicate that these perceptions are related to the importance that the authorities place on the different stages of the disaster cycle (prevention, preparedness, response, and recovery). The local patterns of participation that have emerged from this governance analysis suggest that the citizen observatories can take specific ‘shapes and sizes’ in the three locations.
Drivers and Barriers to Multi-Layered Flood Risk Management: a Comparative Study of Dutch and Us Practice (PAP014831) - Full Paper
Keywords: Flood Risk Management, Decision Making, Multi Layered Safety, Contextual Factors
Subject: Flood resilient societies through community preparedness
Abstract:
After decades of primary focus on protection, the 2009 Dutch National Water Plan introduced Multi-Layered Safety (MLS) as national policy that also integrates spatial planning and emergency management into flood risk management. Around the same time, a number of regions in the US started exploring “multiple lines of defense” and implementing non-structural flood risk management programs. It proves to be difficult, however, to implement MLS in practice and to (optimally) balance investments across all three safety layers.The purpose of this paper is to identify and compare drivers and barriers to the implementation of MLS in Dutch and US practice. In total, six case studies have been analysed and compared: three in the Netherlands (Kampen, Dordrecht and Almere) and three in the US (Valmeyer, Stockton and Natomas). The case study analysis focused on the participative process and development of the local strategy for flood risk management, the role of each safety layer within the strategy, and the rationale behind the strategy. In the analysis, specific attention was given to geographical, social and political contexts.Drivers for implementing prevention measures (layer 2) were mostly tied to environmental regulations, social values and aesthetics. In Kampen and Almere, the region wanted to preserve the aesthetic and environmental quality that they felt would have been destroyed by simply building a large dike. In Natomas, the environmental stipulations of the Endangered Species Act actually required that the communities protect land for habitat values by purchasing conservation easements that would ensure land would be permanently in nature.Investments in preparedness (layer 3) were influenced by geographical and physical factors. In Almere and Natomas, the presence of deep and densely populated polders demanded sufficient evacuation routes. Regulatory factors drove preparedness measures in both the Netherlands and the US.
Bmp in Brazilian Cities - Standardization and Application (PAP014834) - Full Paper
Keywords: Floods, Urban Drainage, Water Resources, Urbanization
Subject: Urban Floods
Abstract:
The problems with the floods in large urban centers is a recurring theme for the technical community and, also, one of the greatest challenges, hence the solutions are becoming ever more difficult and expensive than what they would be had there been the presence of planning prior to the occupation. In these metropolis, the main road system is consolidated in the lowland areas along the major rivers, thus resulting in large-scale material losses and in other non-measurable losses as well, such as the loss of lives.Apart from the impact of the sealing of ground surfaces - in which large volumes are generated over a short period of time - the quality of the water is worthy of regard. In addition to the material carried by the water drag, there is a large amount of contaminating agents, which compromise the treatment and the self-purification of the bodies of water located downstream from these points. In the system of conventional drainage, there is no concern for the reduction of the peak waves and, likewise, for the quality of the water, whilst, in many cases, the problem is pushed on to the smaller-sized municipalities that have no conditions of affording protective measures.These concerns have led the technical community to rethink the conventional system of drainage and to seek ever more sustainable solutions, with a focus on reducing the massive impact of the storms whilst trying to minimize the concentration of pollutants in the waters. The great challenge lies in the feasibility of deploying those techniques in locations that are densely populated and with few spots available for the implementation of these solutions.The standardization of the nomenclature and the classification of these methods is proposed, with aims at making them more accessible to the technical community, making them more applicable, and trying to support and disseminate such concepts based on the international bibliography, whilst adapting them to the Brazilian reality.An example of application with the use of the techniques in a consolidated urbanized area has been provided in an effort to demonstrate solutions which adapt to the midst and, at the same time, promote environmental and urban improvements for the city.
A Quality Analysis in Hydrological Forecasting. Lessons Learnt From the Basque Country Flood Early Warning System (Spain) (PAP014836) - Full Paper
Keywords: Flood Early Warning System, Quality analysis, Uncertainty quantification
Subject: Flood forecasting and early warning systems
Abstract:
Flood early warning systems are increasingly becoming a common tool to reduce flood risks in wide parts of a certain region or country. Their low investment needs, short implementation times and significant effectiveness make them a desirable protection measure in comparison with other structural solutions. Nevertheless, in order to fully exploit their potential there are certain requisites that must be fulfilled, such as the availability of accurate real-time hydro-meteorological data, the development of well-calibrated hydrological models, the existence of detailed meteorological forecasts, the use of data assimilation algorithms and the implementation of a reliable integration software that ensures a proper automation of tasks. Advanced systems are now including weather ensembles and radar nowcasting as a way to improve hydrological forecasts and take into account the related uncertainty. However, before getting into more complex calculations, a special attention should be paid to the current quality of the system in an effort to identify the elements that mainly contribute to its performance. Such an exercise has been made in the Basque Country Flood Early Warning System. The hydrology of the region has torrential features, both due the occurrence of very intense and persistent convective storms and due to the fact that rivers are short and with steeply slopes, which means they have small concentration times. Therefore, a correct rainfall observation, a reliable short-term rainfall forecast, the availability of adequate antecedent moisture conditions, a valid model response and a consistent data assimilation procedure are key factors that need to be analysed and cross validated. Here we present the results of this analysis and the alternatives proposed to overcome the detected pitfalls, which in overall will contribute to build a better simulation core before other developments area implemented. In addition, this new developments are also outlined and their potential effect on the system discussed.
The Role of An Accurate Estimation of Expected Damages in Flood Risk Management. Examples From the Basque Country (Spain) (PAP014837) - Full Paper
Keywords: Flood damage, Cost-benefit analysis, Flood protection planning, Basque Country
Subject: Flood risk management in mega cities
Abstract:
Dealing with a highly affected territory in terms of floods with a limited budget is always a difficult exercise of optimizing resources. In this scenario, flood protection policies must always be supported by an objective scheme in order to avoid any bias in allocating funds due to the subjective impact of recent episodes or to unjustified social demands. In accordance with the new European flood legislation, a comprehensive approach for flood risk management is presented here. It is organized in three different phases with the following aims: 1) to identify the areas that comprise the bulk of the potential damages within the studied region; 2) to elaborate flood hazard maps in the selected areas with state of the art hydrological and hydraulic techniques, as well as to elaborate flood risk maps including a detailed account of annual expected damages both in terms of affected population or likely casualties and of economic losses; and 3) to propose efficient structural measures starting with those that will reduce the overall flood risk quicker than others and to promote non-structural ones, such as early warning systems, reforestation, insurances, etc. The adopted methodology goes beyond the one proposed by the EU and is open to be discussed with the respective environment agencies. In the aforementioned procedure, an accurate calculation of flood damages is essential. Annual expected values must be close to reality if a proper cost-benefit analysis is to be conducted and its results regarded as valid. They must then include the impact of floods on buildings, goods, vehicles, infrastructures, etc. Once this is achieved, policy makers have a powerful tool to answer some critical questions, such as how to prioritize areas, which protection level is desirable or how to choose between protection alternatives. Some examples from the Basque Country (northern Spain) are provided.
Vulnerability to Flooding in the City of Sao Paulo (PAP014839) - Full Paper
Keywords: Flooding Risk, Urban Vulnerability, GIS
Subject: Flood risk management in mega cities
Abstract:
The city of São Paulo is the largest in Brazil, covering 1,500 km², population of approximately 12 million inhabitants ( IBGE , 2011) and watershed areas over than 80 % impervious. This level of soil sealing has a fundamental role in increasing the risks associated with flooding and mass movements due to increased runoff, taking the concept of risk as the product of the probability of the event, exposure, vulnerability and potential damage. This article shows the construction of curves flooding vulnerability for different basins in the city of São Paulo, according to the probability of the rainfall event, based on the historical analysis of such incidents over 10 years of records . Based on the data analysis of instantaneous rain records from the meteorological radar of Sao Paulo combined with 23 telemetric surface rain stations, 7 extreme rainfall events were selected and flooding incidents records were consisted by assessing those effectively linked to the rainfall event. Resulting valid data where fitted to the probability of occurrence in terms of return period and also the duration of the event, through GIS tools. The sigmoid-type resulting functions show vulnerability to floods of each studied basin for 2, 5 and 10 year return period events, and the associated spatial distribution of this vulnerability in São Paulo. It also presents the spatial analysis of occurrences of flooding within and outside the perimeter of the so called expanded center, which coincides with the areas under the influence of the main arteries of vehicular traffic and traffic restriction polygon, adopted in the city for urban mobility improvement. Data also point that, as in most Brazilian cities, the main road infrastructure of the city, mostly built on the floodplains of rivers and streams and often with closed sections structures, is vulnerable to events of 2 year return period.
Expert System for Dam Assessment and Emergency Detection (PAP014840) - Full Paper
Keywords: Dam Assessment, Dam management, Flood Risk, Intelligent Systems, Fuzzy Inference Systems
Subject: Flood forecasting and early warning systems
Abstract:
This work will present an intelligent system integrated to Cemig's (which is one of the most solid and important groups in the electric energy segment in Brazil) corporate software and data environment. The intent of the expert system presented in this work is to provide a core model that is able to flag the state for each of Cemig's dams given a set of field data. Since the state of a dam could be flagged as being either green, yellow, orange or red, the model should be wise enough to process many inputs such as reservoir level, flood forecasting, data from piezometers (and many other sensors) and even crack reports (which, in this example, might also add a set of subjective data that might be hard to map to real numbers) that are filed at real time, in order to compute the state of the system (the output of the expert model) as being one of these four states. To accomplish this task, the proposed methodology uses a fuzzy rule-based approach to compute the state of the system. However, under some circumstances, those rules might not be available or might be incomplete for some dams, hence the proposed methodology not only uses fuzzy rules to compute the state of the system, but also proposes an approach for auto-generating the rule database when they are absent or incomplete. Therefore, the proposed methodology not only innovates when using expert systems for dams assessment in the Brazilian scope (this technique has been proved to be effective by a couple of researchers worldwide, however, such approach has never been evaluated in the Brazilian river basins and its dams), but also innovates when proposing a totally new concept of auto-generated fuzzy rules. Moreover, the proposed innovative model was designed to be the core element an integrated software which is still under development in the Cemig corporate environment and is called "Integrated Mobile-Web Smart System for Dam Assessment and Management". This system is a big framework that intends to create a unique solution to cover the whole spectrum of dam safety management.
Validation of the Flood Maps of Belo Horizonte: Case Study of Ressaca Catchment (PAP014842) - Full Paper
Keywords: Flood Management, Flood Inundation Maps, Floods alerts, Monitoring
Subject: Flood risk management in mega cities
Abstract:
The main Brazilian cities are lately passing through major challenges in urban drainage due to the rapidly and disordered urban growth, that causes major flooding events. In order to diagnose the causes of urban drainage problems and its integration with other urban systems, the Municipality initiates, in 1999, the elaboration of the drainage master plan, which in its first step performed catchments characterization; cadastral survey of the drainage system and creation of a georeferred drainage database. In 2006 the second stage of drainage master plan was initiated, resulting in the hydraulic and hydrological modeling of all channelized streams; identification of the areas potentially susceptible to floods with its association of risk level – here called Flood Inundation Maps; proposition of a management model for the city and implementation of a hydrological monitoring program. Among the products developed in the second stage of the drainage master plan, we highlight the Flood Inundation Maps and the hydrological monitoring program. The Flood Inundation Maps were developed based on the results of hydrological and hydraulic modeling of the drainage system, in which were identified channels reaches with hydraulic inadequacies, parameterized in terms of probability of occurrences of extreme flows, besides no flow and water level measurements existed. The association between the water levels of flooding and rainfall were performed using equation the IDF (Intensity Duration Frequence) in a Risk Chart. With the hydrological monitoring, program that begins its operation in October 2011, it is possible to validate the Flood Inundation Maps and the Risk Charts. These Risk Charts consists in a graphical tool linking rain heights and duration to a flooding risk level, allowing flood forecasting. It was elaborated for each stream where flood occurrences were identified. The present work concerns the validation the Risk Chart of the Ressaca’s Catchment.
Influence of Load Interdependencies of Flood Defences on Probabilities and Risks at the Bovenrijn/Ijssel Area, the Netherlands (PAP014849) - Full Paper
Keywords: Flood Risk Analysis, dike safety, load interdependencies, system behavior, dike breaches
Subject: Impact of climate change on flood risk
Abstract:
In the Netherlands, flood risk analysis is usually carried out for a location, without considering potential flood defence failures in upstream areas. This may result in significant over- or underestimation of flood risks. The effect of upstream failures on failure probabilities and flood risks in other areas is called load interdependence of flood defences. This effect can be both positive and negative: loads on a certain defence can increase and decrease due to failures upstream. In this research a framework was developed which enables the consideration of these interdependencies in a probabilistic framework. This was done by using Monte Carlo with Importance Sampling and a fast inundation model, which enables considering many scenarios with many different breaches. The case considered was the Bovenrijn/IJssel area in the Netherlands, a lowland river area where dike breaches can have both positive and negative effects on the loads on other flood defence elements. The risk estimates and changes in water level probabilities in the considered area show a clear interrelation between loads on different elements of the flood defence system and demonstrate that the effects of dike breaches on loads and risks on other locations cannot be ignored in flood risk analysis.
Restrictions on the Use and Occupancy of Flood Areas as a Tool for Disaster Reduction (PAP014854) - Full Paper
Keywords: flood management, flood risk prevention, land use plan
Subject: Urban Floods
Abstract:
In Brazil, disasters related to floods causing human damage, pecuniary loss and environmental damage, are mainly due to greater exposure of the population; urban densification on the riverbanks and margins, incurring vulnerability due to changes in river level. The territorial and environmental management policies have not been enough to prevent disasters considering the lack of articulation among the States and the Federal Government, water management by hydrographic basin, and the Municipalities, which are responsible for performing the territorial management. Several efforts have been made in recent years following the tragedy of the Região Serrana (mountainous region) of Rio de Janeiro State, which seems to have put the matter on the political agenda of the whole country. The paper lies within this context, as it deals with the theme of urban flooding from the point of view of prevention of the emergence of vulnerabilities and the consequent reduction of the risk of flood-related disasters. A survey is conducted of the legal basis (urban and environmental) in order to assess the potential for development of public policies to prevent occupancy of areas subject to inundation, especially in regions of great urban expansion, avoiding or reducing the risk of such disasters. Furthermore, assessment is made of the recent government actions, focused on flood prevention, performed at Federal and Rio de Janeiro State level.
An Interpretation of 'Water Sensitivity' and 'Resilience' Bringing Together Flood and Drought Risk Management (PAP014860) - Full Paper
Keywords: drought, flood risk, resilience, water sensitivity
Subject: Flood resilient societies through community preparedness
Abstract:
Water Sensitive Urban Design (WSUD) defines a new paradigm in total water cycle management that integrates both the engineering and ecological professions associated with protection of urban water resources and also the built environment professions. Synergistic integration between the extant knowledge on WSUD together with resilience concepts, can lead to the establishment of a new model for Water Sensitive Cities, which are also resilient to floods and droughts.Sensitivity and resilience are concepts frequently defined independently from one another. Having a myriad of concepts for sensitivity and resilience, it is important to establish the provenance of these; what is their current status, and where are they heading to, in such a way that the ‘grey zones’ of vagueness are covered and the definitions made clear for both researchers and practitioners in the field of water cycle management. Moreover, it is necessary to show how to assess the sensitivity and resilience of urban areas as an outcome.Bringing together both concepts can advance their application with respect to flood and drought risk management. The interaction between sensitivity and resilience can best be considered by identifying the system response curve and recovery threshold. Comparison of the response curve with the recovery threshold provides an indication of the boundary of resilience of the system. If the response curve exceeds the recovery threshold, the system is not likely to persist and no longer be robust, shifting to another regime.This paper updates the 3 Points Approach (3PA) to assist in placing urban surface water within the land use, urban design and planning process so that maximum value can be obtained from the synergies between surface water and other urban systems. The updated interpretation of the approach considering four different domains, allows a better understanding of the continuous process in relation to resilience, sensitivity and the point at which a regime shift occurs.
Macro Drainage and Retention of First Rain in Closed Catchments (PAP014886) - Full Paper
Keywords: Urban Catchment, Macro Drainage, First Runoff Detention
Subject: Urban Floods
Abstract:
This paper deals with an unconventional solution of urban drainage for Natal city, RN, Brazil. The city is on closed drainage basins so that runoffs flow radially to the lowest points where lagoons or hydraulic detention reservoirs are situated. Originally, under natural conditions, the shallow areas formed ponds during rainy periods. However, urbanization and bad planning for land use increased runoff and shallows so that resulting quickly in frequently flooding damages. Construction of reservoirs with sufficient volumes to store rainwater and / or pumping systems to transfer the surplus water to other places were continuously implemented as the developing city urbanization occurred. This macro drainage alternative has been established itself in the city. However, as the system drainage increased and becomes complex it should be necessary to integrate water diversion by some new transposition system. The present study refers to the design of the Integrated South Zone Macro Drainage System of Natal City. The main system project design evolves sizing of the main gallery, tunnel type built by nondestructive method. Macro drainage system involves six neighborhoods, a large part of south zone of Natal city. In order to solve permanently the problem of flooding it was designed an integrated drainage system, consisting of a complex system of detention reservoirs, which correspond resizing existing ponds, interconnecting them in series by galleries and tunnels, which act as spillways system to the Potengi estuary. The implementation of this system reduces to acceptable levels the risk of flooding in the area. The design system evolves also water quality aspects. The effluent quality of an urban drainage system changes enough during the rainy season with the washing of paved drainage basin, gradually reducing their polluting head. This aspect justifies thus the incorporation of absorption devices for the retention of the first rain in the design and construction of macro drainage systems. In the design of detention reservoirs. It considers also the effective precipitation (Pefe) which determines the volume capacities of the hydraulic detention reservoir.
Interference of the Land Use on Flooding in An Urban Area (PAP014891) - Full Paper
Keywords: Land use, urban area, flooding
Subject: Urban Floods
Abstract:
The first populations have settled near the rivers and as they have expanded there was an increase of impervious areas, and the suppression of floodplain areas. This fact contributes to changes in river hydrology and hydraulics and to the increased floods. Thus, this work aims to verify the interference of land use on floods in the urban area of the Servidão stream basin, Rio Claro (SP), in different scenarios, i.e., pre- and post-occupation scenarios. For this, the Soil Conservation Service model based on the land use characterization for all scenarios were evaluated, thus permitting to measure the variation on hydrograms and flow peaks. The results indicated that increasing the waterproofing, for the growth of the Rio Claro city, was responsible for the first event of flooding of the city. The government has been doing some engineering work and transferring most of the problems with flooding to downstream areas, where floodings still occur.
Challenges of the Hydrological Monitoring of Small Hydrographic Basins: Case Study of the Mineirinho Stream Basin, São Carlos (Sp, Brazil) (PAP014892) - Full Paper
Keywords: Urban rainfall, urban streamflow, hydrological monitoring
Subject: Urban Floods
Abstract:
Acquisition of hydrological data is essential for managing basins and hydrology studies.Implementing a hydrological monitoring network, however, is a complex and unique task.Its planning andimplementation involve aspects related to the monitoring objective, the nature of the data, the study areaand the available equipment. The implementation is even more complex in urban areas than in rural ormixed basins because the choice of equipment and the selection of installation points present variouschallenges. These challenges involve subjecting the professionals and equipment to risks or relaxing thetechnical recommendations so that the task is fulfilled. This article addresses the obstacles and solutionsfound during the installation of a hydrological monitoring network in the Mineirinho urban stream basin inSão Carlos(SP), Brazil. The network has equipment for rainfall, streamflow and water quality monitoring.The selection of points for installation, the choice of equipment and the advantages and disadvantages ofthe solutions found by the working team are presented.
Assessment of Genetic Algorithms in Calibration of An Unsaturated Soil Water Flow Model Applied to a Vertical Infiltration Experiment of Two Layers of Soil (PAP014901) - Full Paper
Keywords: Unsaturated soils, Model of van Genuchten (MVG), Genetic Algorithms (GA)
Subject: Land use and Floods, landslides and erosion
Abstract:
This paper aims at assessing the genetic algorithms for automatic calibration applied to a model that simulates an experimental study on water infiltration in two soil layers. There is the problem of interface between layers of soil. The numerical model of Koide (1990) was used. With the computational progress, the researchers chose to use the inverse model for calibration models. That inverse model was utilized in connection with Genetic Algorithms (GA) that is a mathematical technique that optimizes an objective function (OF). The use of a single FO drifts problems of uniqueness. This article uses the colected data from the phenomenon of infiltration of two layers of sandy soils accomplished by Elmaloglou et al. (1980). The results show that the simulation of the experiment, including the interface between layers, is reasonable and there are multiple sets of parameters as responses that calibrate the model.
Analysis of a Antropic Influences in a Floodplain (PAP014904) - Full Paper
Keywords: floodplain, water bodies, antropic influence, hydrodynamic model
Subject: Land use and Floods, landslides and erosion
Abstract:
Floodplain are lateral areas that receives the excess of rivers during floods and were, originally occupied by vegetation or dunes. In the urban environs, those areas were replaced by buildings and other impervious structures, converting natural events in source of losses and public calamity This paper presents a case study where changes in the river behavior in terms of water level, caused by antropic influence as civil works, dredging and urban occupation are correlated. The study area is located on the on the left bank of Turvo River, São Luiz do Paratinga / SP - Brazil and the interventions that affected the river behavior were generated by the use the floodlain areas to store civil works disposals in the city rebuilding process, after the rainfall events that caused critical flooding in January 2010 and devastated the city. Analyzing resulting water profiles computed through an hydrodynamic model, it was possible to verify the influence of the disposal areas in river runoff and establish the maximum area that could be used for that activities to avoid damages. This way, this study concludes with and remarks the need for preservation of floodplains or valley bottom of urban water bodies.
The Issue of Quality of Stormwater: Analysis of Diffuse Loads in Brasilia, Distrito Federal, Brazil (PAP014905) - Full Paper
Keywords: diffuse pollutant, urban watershed, monitoring
Subject: Land use and Floods, landslides and erosion
Abstract:
The water quality in water bodies can be affected during rainy seasons due to contribution of stormwater contaminated by diffuse pollutant loads from runoff generated by precipitation events carries the pollutants, accumulated during dry periods. Therefore, it was aimed in this study to evaluate the pollution loads from stormwater in countries like Brazil, where domestic sewage have a separated collection network and stormwater are discharged directly into water bodies without any treatment. Hydrology data (rain and flow) and to water quality data (Suspended Solids, Organic Matter - COD, nutrients - nitrogen and phosphorus) were collected during two rainy seasons (2012 – 2014) in Brasília, Brazil, with defined rainy and dry seasons, and mean rainfall of about 1500mm (Inmet, 2010). After two years monitoring stormwater in two small urban watershed which discharged in the Paranoá Lake, it was observed that the pollution of urban waters is related to the rainfall intensity, the number of days between their occurrence and spatial distribution and also varying according to the use and occupation of land in the urban watershed, which vary significantly, even in small areas. Highest loads were observed during the more intense events, reaching, levels in the range of the existing wastewater treatment plant loads like in the extreme event of November 2012 in which the loads reached values of 31.44kg/day/ha of SS, 36.89kg/day/ha of COD and 3kg/day/ha of nutrients. It can be noted that the problems and inconveniences caused by the floods goes beyond the level of the water or flooding, because their final destination pollute the water resources of the cities. Thus, in places where these loads are significant like in the studied area is important to adopt sustainable techniques in order to reduce diffuse pollution and the effects of urbanization on the hydrological processes and water quality.
Reservoir Operation Employing Hec-Ressim: Case Study of Tucuruí Dam, Brazil (PAP014913) - Full Paper
Keywords: Forecasting, HEC-ResSim, Operational regulations, Reservoir operation, Tucuruí Dam
Subject: Flood forecasting and early warning systems
Abstract:
Due to Brazilian hydroelectric potential, the construction of dams is a common practice in the country. Its purposes are multiple, playing an important role for energy production, water supply, flood and drought control, irrigation, recreation, navigation, and so on. Although the benefits entailed to society, the issue of operation of reservoirs should be object of study and critical evaluation, since they are not free from extreme event occurrences. Therefore, the operation of the reservoirs is a relevant topic of the management of water resources, and conflicts about their operation constraints can be related to water use at catchment scale. So economic, social and environmental aspects must determine the goals of the operational rules to minimize those conflicts, and support the Brazilian legislators to ensure the proper laws and regulations to manage the water resources dependent on reservoirs. The employment of computational models can assist managers and legislators nationwide in the search of these regulations for the determination and maintenance of the reservoir operation for multiple purposes. This paper presents a straightforward case study employing the HEC-ResSim model. HEC-ResSim is one of the simulation models that possess of multi reservoir simulators and can simulate water resources systems. The presented study was subsidized by daily observed data from 2001 up to 2006 of pool elevation, inflow and outflow discharge. In addition, geometry and hydraulic data from dam and reservoir were employed to develop the numerical model. The hydrological analysis was performed to understand the operational constraints of the Tucuruí Dam´s reservoir, located in the state of Pará, Brazil. The operational rules were evaluated according to the characteristics of the reservoir storage, the flow capacity of the spillways and the flow capacity of the river drainage downstream of the Tucuruí Dam. Finally, there is discussion how to integrate the tool in a real-time forecast system.
Evaluation of Alternatives for Reducing Flow Peaks in a Urban Watershed (PAP014915) - Full Paper
Keywords: Flow peak, HEC-HMS, Urban flood, Urban Watershed
Subject: Urban Floods
Abstract:
The lack of planning about the increasing urbanization processes, mainly regarding theirregular occupation of riverbanks and hillsides, the channelization and straightening of river beds and thesoil sealing has caused, among others environmental problems, the reduction in rainwater infiltration. Thereduction in the infiltration and the increment in the runoff fraction result in increased flows during rainyperiods, contributing to flood occurrence. These factors can be potentialized if the disorderly occupationoccurs in an urban watershed where critical morphometric parameters are observed, like high values ofcircularity ratio. This study aims to evaluate the efficiency of alternatives implementation that lead toamortization of flow peaks responsible for flooding thorough different scenarios based on simulation ofhydrological processes occurring in an urban watershed. Analyses were performed with the HydrologicalModeling System (HMS) software, developed by the Hydrologic Engineering Center (HEC) of US ArmyCorps of Engineers (USA) and the ArcGIS software, among others. As a case study, simulations weredone in a watershed with great historical problems of flooding events and which comprises the city ofUberaba, located in Minas Gerais State, Brazil. The simulations shown that the implementation ofindividual measurements, such as, channels cleaning, intervention in agricultural areas and theconstruction of reservoirs, if taken in isolation, have negligible changes in peak flows. The evaluation ofan already constructed reservoir that has a superficial area of 101,640 m² indicated an efficiency of 4% inpeak flow reduction. The set of measures to improve infiltration in urban area, through implementation ofgreen roofs, permeable pavements, percolation basins and reforestation, associated with reservoirconstruction in areas still available in the urban space, showed a satisfactory result, reducing theobserved peak flow in 18%, besides the delay in time of concentration. It can be concluded that, in thesecases, the combination of structural and non-structural measures should be prioritized in publicmanagement, as flood effects are related not only to natural resources degradation, but also, represent apublic health problem, having significant impacts in social, economic and environmental areas.
Intense Rainfall Over the Region of Serra Do Mar - Brazil (PAP014918) - Full Paper
Keywords: Natural disasters, representative monitoring network, intense rainfall
Subject: Land use and Floods, landslides and erosion
Abstract:
Expressive amounts of rainfall may occur during the summer season along all the extension of the mountainous region known as Serra do Mar, which encompasses portions of four states in Brazil - Santa Catarina, Paraná, São Paulo and Rio de Janeiro -, causing landslides and floods. Inter-annual and intra-seasonal oscillations with significant variability in spatial location and range of coverage can be observed, when the phenomenon is analyzed at the appropriate scale. The hazards vary according to geomorphology and land use and the severity of the associated disasters increases with disordered urban occupation. In December 2013 an extremely heavy rainfall occurred over the states of Espírito Santo (ES) and Minas Gerais (MG), killing 45 people and leaving more than 10.000 homeless. These two states are near the region of Serra do Mar forming with it a wider region where the South Atlantic Convergence Zone (SACZ) episodically acts increasing significantly the amount of rainfall during spring and summer. The event of December 2013 resulted from the configuration of some SACZ episodes acting in a sequence over the same area, with little spatial variation from one to the following episode. In this work the frequency of the event is evaluated using data observed in different gages within the region and available Intensity-Duration-Frequency (IDF) curves from a study performed for the whole country in the 1950's. The rainfall amounts registered during the event by 64 available automatic gauging stations and observed at other 127 daily gauging stations are compared to Tropical Rainfall Measuring Mission (TRMM) data sensed over the affected area. The representativeness of the existing monitoring network was evaluated as the TRMM data were validated using time wavelet transform methodology and a multiresolution analysis (MRA).
Environmental Analysis of Aquidauana River Flood Plain of the Prelude of South Matogrossense's Pantanal: Floods and Risks to Reverberate in Aquidauana/Ms Town (PAP014919) - Full Paper
Keywords: Vulnerability, Risks, Aquidauna River, Rainfall excesses, Flood
Subject: Urban Floods
Abstract:
The Aquidauna town is located in the western region of the state of Mato Grosso doSul, Brazil, is considered part of the Plain Pantaneira's Protection Zone. This work seeks to reflectthe environmental vulnerability of floodplain inundation on the right bank of the river Aquidaunawithin the city, emphasizing the degree of risk to which it is exposed population, urban mappingfunction in flood area, identify the intensity of the magnitudes seasonal flooding between 1976 and2013 to determine the chronological time of exceptional magnitude floods occurred in this periodwithin the urban area of the municipality of Aquidauna. To achieve the objectives questionnaires onthe right bank of the river Aquidauna were performed within the floodplain, site visits, job mappingthrough CAD software for design, survey data quota, flow through the system and rainfall atHydro Web system. The results of the study identify flood risks associated with the housing, whichcan be classified in Low - R1, Medium - R2, and High - R3. It was found that the area about 40 %of the homes is in a high risk situation (R3), demonstrating that environmental vulnerabilityassociated with rainfall excesses arising from climatic extremes exposes the society to a criticalsituation and susceptible to frequent flooding , when the magnitude of the water moves toward itsfloodplain flood impacting the Aquidauna town. Becomes plausible structural measures, compliancewith what is established in the legal instruments and the federal, state and municipal levels, as wellas preventive and emergency actions converging minimization and solution to the impacts resultingfrom the demonstrations in the coming episodes of flooding at the climate extreme.
Metropolitan Ring Road - Land Use and Flood Control in the Rio De Janeiro Metropolitan Area (PAP014920) - Full Paper
Keywords: flood management, urban plan, flood control
Subject: Land use and Floods, landslides and erosion
Abstract:
The Metropolitan Ring Road is one of the major works in progress in the Rio de Janeiro Metropolitan Region. The new road will act as a bypass for the long-distance traffic between the South / Southeast and the North / Northeast regions, its arc connecting with five federal highways and intersecting a railroad, as well as serving several large industrial complexes being established in the metropolitan area. Moreover, the Metropolitan Ring will provide broader accessibility to the Port of Itaguai in Sepetiba Bay, such as for the Petrochemical Complex of Rio de Janeiro (COMPERJ), located in Itaboraí. Also it will permit the establishment of logistics terminals that will reduce travel times and transport costs, as well as improve connections to consumer markets. On the other hand, the construction of the ring road will introduce new vectors of urban expansion for the municipalities located in its area of influence, thus potentially changing the land use. The new road will cross the Baixada Fluminense, a lowland region notorious for flooding problems. Sustained urban development of this zone would have to provide flood control in the Iguaçu-Sarapuí river basin, which could only be achieved by controlling the urban sprawl and land use. Some areas of this zone are still free of urbanization, the vegetation cover and natural soil infiltration being responsible for retaining some of the rainfall runoff in the upper reaches of the Iguaçu-Sarapuí drainage basin. This paper aims to discuss strategies for the Baixada Fluminense to maintain its areas of low hydrological impact and keep the open spaces free of urbanization.
Climate Influences on the Flood Hazard Across Brazil (PAP014921) - Full Paper
Keywords: Flood Frequency Analysis, Flood Risk, Poisson Regression, Climate
Subject: Impact of climate change on flood risk
Abstract:
Flood risk management and flood frequency analysis have relied on the stationary and independence assumptions of random events, whereas the probability associated with a given flood is constant across time. However, climate variability and land use changes may impose significant modifications in the physical processes associated with extreme rainfall-runoff events in a given region which in turn may alter the flood hazard for short or long periods. In this case, identification of the key climate variables associated with the flood hazard variability is particularly important if one wants to assess the impacts of climate change on the flood risk. Here we explore the hypothesis of a time varying flood hazard for several streamflow gauges in leading locations across Brazil by analyzing historical streamflow series and large scale climate teleconnections associated with their interannual variability. Particularly, we define the flood hazard as the probability of the daily flow to exceed some pre-defined threshold value, e.g., the 90th daily streamflow percentile. For each year and gauge, the number of days in which the daily streamflow exceeds the threshold value is then stored. In order to consider only time independent flood events, we decluster the daily streamflow series by taking only flood events in which the inter-arrival time is greater than three days. The interannual variability in the number of flood events for each site is then associated with climate variability in a Poisson regression framework, whose covariates are representative of ENSO, of the meridional position of the Intertropical Convergence Zone (ITCZ) and of the monsoon system over South America. The spatial distribution of the regression estimates are then used to depict a quantitative view of the most sensitive regions in Brazil in terms of flood risk changes due to ENSO, ITCZ and monsoon variability. Finally, the implications of potential future changes of such large scale climate systems on the flood risk in the country are discussed.
Interaction Between Urban Spatial Organization and Flood Risk. Taipei Case Study (1895-1945) (PAP014928) - Full Paper
Keywords: Flood risk, resilience, Taipei, urban spatial morphology
Subject: Flood resilient societies through community preparedness
Abstract:
Using a systems approach, a city can be considered as a complex system divided into several subsystems. Each of these systems require numerous regulations which enable the actors, at all times, to maintain or reestablish desirable urban functions during/after disruption from external events such as natural hazards. In this sense, flood risk could be considered as one of elements which can trigger urban regeneration. Among urban subsystems, our research focuses on the urban spatial morphology (USMS) which is made of geographical, physical and societal components. Surrounded by steep hills on three sides, Taipei is located on the floodplain of the Danshuei River. According to historical records, typhoons sweep through Taiwan around 3 times per year. With these geographical characteristics, the city has endured several floods and become more resistant to flood risks by adopting various adaptive regulations and measures. In this paper, a description firstly is given to show how floods caused by typhoons promoted interactions between components of the USM during 1895-1945. Secondly, a demonstration exposes that adapted architectural and urban planning regulations protected the city from flood risks. Finally, an analysis of the City's Master Plan displays that flood risk became one of key components of urban structure.
Lessons for the Past and Opportunities for Insurance Mechanisms of Flood Risk Management in South America Related to International Strategies (PAP014946) - Full Paper
Keywords: flood risk management, Anthropocene's scenarios of change, flood insurance mechanisms
Subject: Floods in a changing climate
Abstract:
This paper present recent past lessons and feasible opportunities of flood risk management (FRM) in South America. The total 'flood market' in South America is estimated at about US$80 billion a year and is expected to increase until 2075, converting reactive policies to proactive ones. South American countries are affected annually by a 2% to 5% decrease in GDP caused by non-prevented floods, which are converted to social disasters - the so called 'flood- poverty-cycle' (FPCycle). Anthropocene's drivers of the food-water-energy nexus force FRM to rapidly adapt to increasing FPCycles. On the one hand, accumulated losses from the South American floods were approximately US$25 billion in the last decade, including immediate repair and operation and maintenance (O&M) costs. Total figures outline that post-flood restoration plans transfer annual debts, with rates of US$30 to 3,500 per capita, to populations living at either poor, vulnerable settlements or even at metropolitan areas, respectively. Moreover, transboundary nature of South American river basins enlarge these impacts. Until year 2010, there was a net positive increase in O&M flood losses of about US$2 billion a year, either because of lack of prevention or contingency flood plans. On the other hand, preliminary scenarios up to the year 2050 outline the possibility of reducing costs at a relative annual rate of US$150 per capita through wise FRM, and reducing the FPCycles by an order of magnitude of fifty times with appropriate flood strategies and new public-private partnerships. Alternative scenarios show that O&M costs could reduce to US$0.5 billion a year until 2020 if early warning systems are included in river committee plans, with an increase in the monitoring and forecast of impacts in ungauged basins. A new emerging gap with a transition phase in South American FRM is foreseeable, as concepts of flood disaster mitigation are increasingly replaced by visions of early-warning systems and transfer-risk devices through flood insurance. This study present a comparative appraisal of how flood insurance mechanisms could be feasibly adapted for scenarios of changing climate. We present not only methods of assessing risk of flooding, but also strategies useful for vulnerable communities, with some comparison with other strategies in North America, Europe and Asia.
Scenario Evaluation of Alternatives for Flood Control in the Anhangabaú Watershed, Brazil (PAP014950) - Full Paper
Keywords: urban flood, hydrologic and hydraulic modeling, retention structures
Subject: Flood risk management in mega cities
Abstract:
Flooding and overflows are common and recurring problems in several Brazilian cities, which usually undergo disorderly development. Their causes vary from increased impervious surface areas, deficiency / inefficiency of drainage structures and their maintenance, siltation of rivers, channel obstructions and climatic factors. This situation is even aggravated when occurred in large cities. The Anhangabaú Watershed lies in the central portion of São Paulo – Brazil and covers a drainage area of 5.4 km². The region is highly urbanized and is crossed by an important north-south road connection. During heavy rain period, portions of this interconnection passage become compromised, disrupting the flow of vehicles, creating a chaotic situation for the population, as well as losses to the national economy.In seeking solutions to the problems of flooding in the basin, which have been studied for decades, the São Paulo City Hall hired Hydraulics Technology Center Foundation (FCTH) to evaluate the performance of two traditional alternatives already proposed for the region system drainage and to offer a new alternative, based on modern concepts of water resources management. Therefore 3 alternatives intended to mitigate the flooding problem in the lower valley were evaluated: (i) 2 flood detention reservoirs and reinforcement of main gallery system, designed to ensure safety against 25-year return period events; (ii) reinforcement of the main gallery and flow derivation tunnel leading to the Tamanduateí River for a 100-year return period; (iii) distributed linear retention spread over the watershed in stages of return periods of 10/25/100-years. The comparison of alternatives was given by a multi-criteria analysis based on six subjects, namely, alternative efficiency, prevented damages, permanent environmental impacts, temporary environmental impact, costs and public response. The evaluation of technical criteria analysis was based on a complex modeling network employing PCSWMM application, representing both road and drainage systems and their interconnections. The alternatives were simulated for different scenarios corresponding to a combination of drainage system, urban occupancy, adoption of LID (Low Impact Development) controls, modeling dimension and rainfall time series.Modeling outputs showed that all alternatives presented relevant results in solving the flooding at critical locations. However, that the alternative regarding linear retention offered better overall effect to solve the problems of flooding in the Anhangabaú Watershed.
Warning System Based on Real-Time Flood Forecasts in São Paulo, Brazil (PAP014951) - Full Paper
Keywords: flood forecasting, hydrologic and hydraulic modeling, radar rainfall, SWMM, warning system
Subject: Flood forecasting and early warning systems
Abstract:
Floods are natural events that can cause victims and various social and economic losses. These events are originated from intense rainfall that exceeds soil infiltration capacity leading to major water runoff that surpasses the capacity of drainage systems causing flooding and overflows. In particular, at highly urbanized basins, the problem becomes even more complex since it involves land use issues, not only by raised flood peaks caused by broadened impervious surface areas, but also by increased vulnerability to flooding due to highest population densities located in flood prone areas. Yet there are frequent cases when the impacts of these floods are aggravated by lack of consistent information, which implies poorly conceived projects, bad maintenance and faulty decisions by public officials, investors and society in general. Based on this scenario, the São Paulo City Hall (PMSP) has invested in a flood management system for evaluation, monitoring, forecasting and warning in order to promote stormwater management efficiency and effectiveness of preventive and corrective actions. Therefore, PMSP maintains a technical assistance contract with the Hydraulics Technology Center Foundation (FCTH). At first, this partnership addressed activities of atmospheric monitoring of precipitation using radar and land precipitation monitoring, as well as channel and reservoir levels through telemetric network and weather forecast. Seeking to understand and evaluate the response of basins and major drainage structures to different precipitation, a rainfall-runoff model followed by a hydraulic model are now being applied to predict outflow and flood extents in critical watersheds, in order to support the management of the impacts of extreme hydrological events.PMSP selected six priority independent watersheds with distinct characteristics that represent about 15.5% of municipal territory area for the initial implementation of this technology, namely Aricanduva, Água Espraiada, Cabuçu de Baixo, Mandaqui, Morro do S and Pirajuçara. Selected watersheds already hold flood control structures, but still experience flood related problems, except Mandaqui.Hydrological modeling of the subcatchments and hydraulic modeling of the main channels were performed employing PCSWMM (CHI), which consists of a set of solutions associated with the core calculation SWMM5 EPA, incorporated into a modern GIS engine. The models were calibrated for each watershed adopting recent extreme event data. As a result, PCSWMM delivers profiles and hydrographs along simulated channels, reservoir states, flood inundation extents and affected buildings. In addition, there is a PCSWMM Real-Time module that discloses prediction results for flood inundation sites based on radar rainfall forecasts, taken every 10 minutes to a prediction horizon of 3 hours. These outputs are addressed to the Emergency Management Center (CGE) in real time on the internet, with an intuitive graphical web-interface, easily allowing access to information and analysis of complex problems by technicians.
Qualitative Diagnosis of the Influence of Silting on Urban Floods (PAP014954) - Full Paper
Keywords: Diagnosis, Erosion, Silting, Urban Flood, Watershed management
Subject: Land use and Floods, landslides and erosion
Abstract:
The anthropogenic interventions in the physical environment, exemplified by activities such as the removal of native vegetation, slope cutting and soil sealing, cause changes in the dynamics of land surface processes in a shorter timescale than observed in the natural environment. Alterations in the environment dynamic balance induce the appearance of accelerated erosion and landslides, whose impact is revealed by the deposit of sediments in drainages. As a consequence, the accumulation of sediments compromises river flow, contributing to the occurrence of urban floods and increasing its frequency and intensity. Through a qualitative diagnosis, the present study evidences these facts, demonstrating that studies focused on the prevention and controlling of soil erosion and landslides are essential for urban watersheds conservation planning and flood control.
Mapping and Economic Impact Analysis of Flood on Rice Field in Upper Citarum Watershed, Indonesia (PAP014961) - Full Paper
Keywords: Flood Mapping, Hydrodynamic Model, Rice Crop Losses Model, Citarum Watershed
Subject: Land use and Floods, landslides and erosion
Abstract:
Flooding events in the Citarum basin not only hit the local settlements, but alsodamaging rice crops and other infrastructures located in the national rice production centers in thenorth coast of West Java. Therefore, these losses then affect the national rice production whichdestabilize food security. The purposes of this study are to analyzing the characteristics of riverflow and flood discharge of Upper Citarum, preparing inundation maps of Upper Citarum in thescale of 1:100,000 with return flood period scenario of 2, 25 and 100 years, and analyzing thepotential for rice crop losses caused by the flood and inundation in the upper Citarum river basin,West Java. Flood return period was calculated based on the Gumbel frequency. Flood andinundation was modeled using HECRAS which was developed by the U.S. Army Corp ofEngineers (2002). While the rice crops losses by the flood and inundation was estimated usingRENDAMAN.CSM model. Potential loss of rice due to floods in the paddy fields on a two-yearreturn period reached 8.4 billion rupiah (USD $ 700,00) , this amount will be tripled in the 25 yearsflood return period and becomes 6.4 times in the 100-year return period. Paddy spikes loss ratio ofthe period of 25 years to 100 years is higher than 2-year period to 25 years. This is because floodproneareas in the 100-year return period not just located in the same area of 25-year flood returnperiod but also includes the wetland area with water levels in between 55 to 110 cm. Losses in thisarea is higher compared to the losses of 25-years flood return periods.
Urban Stormwater Flood Management in the Cordeiro Watershed, São Paulo, Brazil: Are Socio-Political Aspects Incorporated Into the Technical Intervention? (PAP014963) - Full Paper
Keywords: Resilience, Flood Risk Management, Socio-political, Urban Stormwater
Subject: Flood resilient societies through community preparedness
Abstract:
In the urban Cordeiro Watershed, São Paulo, Brazil, impervious surface has reduced stormwater infiltration and the drainage system has become insufficient. Engineering firms have been contracted, under government supervision, to design and implement the construction of six water reservoirs to reduce the frequent flooding impacts. The main purpose of this article is to contribute to the study of the relation between technical and socio-political aspects of urban stormwater drainage, as technical solutions alone have been considered not sufficient. A research carried out shows that local actors see themselves as responsible for the main cause of urban stormwater flooding – solid waste dumped in public places – and that they construct protective infrastructure in their homes and businesses. However, no effort is made by the constructing firms nor by the local government to involve them in strategies to increase the benefits of the engineering technical solution and meet the collective interest. Relevant literature suggests that attention given to social-political complexities during planning and construction of technical solutions and a stronger interaction between technical staff, social actors and local government offer an opportunity to evolve from individual self-reliance into a collective strategy of resilience, enhancing the effectiveness of flood risk management practices.
The Warning Flood System in Taquari River Basin (PAP014965) - Full Paper
Keywords: Warning Flood System, Taquari River Basin
Subject: Flood forecasting and early warning systems
Abstract:
CPRM – Brazilian Geologic Survey is operating a warning flood system in Taquari riverbasin, located in eastern region of Rio Grande do Sul state in Brazil. This system benefits the populationof these cities: Muçum, Encantado, Roca Sales, Arroio do Meio, Lajeado, Estrela, Cruzeiro do Sul BomRetiro do Sul , Taquari and Venâncio Aires. The basin has 26 thousand Kilometers square, and the riverlevels and precipitation are monitoring in 27 gauges. These stations belong to CPRM, AHSul, ANA andother agencies. The CPRM stations have automatic equipment, with collection and transmission every 15minutes via cell phone, which also has conventional equipment with data collection twice daily at 7am and5pm. This system used the meteorological forecast provided by INPE; CEPTEC and INMET. Hydrologicalforecasting models used are based on flood propagation and transformation of rain in discharge. Theinformation is disseminated in CPRM website http://sace-taquari.cprm.gov.br/sace-taquari/ and sent toMunicipal and State Civil Defense, Cemaden, Cenad and ANA.
The Division of Flood Season of Lixianjiang River Basin Based on Fisher Optimal Division Method (PAP014966) - Full Paper
Keywords: Fisher Optimal Division Method, Division of Flood Season, Reservoir Operation, Stage Flood Control Level, Lixianjiang River Basin
Subject: Flood forecasting and early warning systems
Abstract:
It may provide a good basis for regulating the reservoir's stage flood control levels to divide flood season into stages properly, for making best use of flood water resources with the fully guaranteed safety of the reservoir. This paper focuses on the application of Fisher optimal division method to division of flood season for Lixianjiang river basin which is located in southwest China. The basic principles and steps of this method are introduced at first. Then, 5 indexes are selected as the characteristic indicators of torrential rain and flood of the basin, and by use of this method, the flood season is divided into four stages, i.e. June 1 to June 30 for pre-flood stage, July 1 to September 10 for main flood stage, September 11 to October 31 for the interim stage, and November 1 to November 30 for post-flood stage. Also, this result is compared with those by the common statistics method and by the fuzzy set theory method in the end, and it is indicated that Fisher optimal division method is of advantages in comprehensively reflecting the characteristics of climate and underlying surface of the basin, so the flood season division result by this method is more objective and more reasonable.
Operation of the Hydrological Warning System in the Caí River Basin Preliminary Studies (PAP014968) - Full Paper
Keywords: Flood Warnig System, Characterization of Floods, Caí River Basin
Subject: Flood forecasting and early warning systems
Abstract:
This paper presents various issues that arose during the deployment andoperation of the flood warning system in the Caí river basin, for which the answers were soughtby the analysis of the historical series of river levels and of rainfalls. These analyzes includedsetting threshold river levels for the location for which flood warnings are required, research themost likely months of flooding, defining low, medium and high levels for certain gauging station,estimating the travel time of the flood wave between monitoring points, and the totals of rain thatsignal risk of flooding. Particularly, it is studied a simple criterion for setting the flood warningthreshold level. The knowledge acquired has proved important for the understanding of floodevents, providing relevant subsidies to the operation of warning systems.
Flood Management in Alto Do Rodrigues/Rn Through the Analytic Hierarchy Process (PAP014983) - Full Paper
Keywords: Risk, Vulnerability, Disaster, Management
Subject: Urban Floods
Abstract:
The municipality of Alto do Rodrigues was flooded several times (1964, 1974, 1985, 2004, 2008 and 2009). Because of this situation, this research aims to identify the best option within the alternatives and assist in determining priorities for managing flood risk in this municipality, based on management conducted in 2009 and through the Analytic Hierarchy Process (HAP) developed by Thomas L. Saaty (1972) and indicators produced by Cardona et al. (2005). The results expose great options to follow when comparing with the local reality.
An Approach to Developing a Composite Measure for Human Health as An Input to A dynamic Systems Model for Investigating City Resilience (PAP014987) - Full Paper
Keywords: Climate Change, Coastal Cities, Extremes, Resilience, Human Health
Subject: Flood risk management in mega cities
Abstract:
The Coastal Cities at Risk project (CCaR) is a multidisciplinary team project involving 4 cities: Manila (Philippines), Bangkok (Thailand), Lagos (Nigeria) and Vancouver (Canada). The major focus of the project is to develop a system dynamics model to assess the resilience of the cities in the face of sea level rise, storm surges, riverine flooding and extreme precipitation events. The model is capable of accepting multiple inputs. This paper addresses the approach taken to develop a human health input and summarizes the progress to date for Vancouver. Maps are shown that demonstrate how this methodology can be used both as an input for the modeling exercise as well as for “stand alone” investigations.
Building Contraventions and Incidence of Flood in the Lagos Metropolis (PAP014991) - Full Paper
Keywords: Spatial Analysis, Building contravention, Flood, Geographic Information Systems
Subject: Land use and Floods, landslides and erosion
Abstract:
The urge to satisfy the housing needs of the growing population results in indiscriminate development of urban space, including flood plains and canals, without recourse to urban planning and development guidelines. The consequential effect of this unwholesome practice is incessant flooding in the metropolis. This study carried out spatial analysis of flooded areas in Lagos Metropolis. A complete list of streets where flood incidence was recorded in sixteen metropolitan local government areas was obtained from Drainage Department, Lagos State Ministry of Environment. Visitations were made to each of the 211 flood prone streets to obtain information about the causes of flood. These data were integrated within GIS and delineation of streets prone to flood due to building contraventions and poor urban planning was carried out. The results suggest building contraventions along drainage channels and floodplains were the cause of flood in 48.8% of the streets. This paper contributes to the pragmatic and problem-solving integration of urban planning and development with social advocacy for flood management in the Lagos Coastal Megacity which is part of the objectives of the CCaR Project.
From Flood Risk Management to Quantitative Flood Disaster Resilience: a Paradigm Shift (PAP014995) - Full Paper
Keywords: Flood Risk, Resilience, Climate change
Subject: Flood risk management in mega cities
Abstract:
There are practical links between flood risk management, climate change adaptation andsustainable development leading to reduction of flood risk and re-enforcing resilience as a newdevelopment paradigm. There has been a noticeable change in flood management approaches, movingfrom disaster vulnerability to disaster resilience; the latter viewed as a more proactive and positiveexpression of community engagement with flood risk management. As flood hazard is increasing, at thesame time it erodes resilience, therefore climate change has a magnifying effect on the flood risk. In thepast, standard disaster management planning emphasized the documentation of roles, responsibilities andprocedures. Increasingly, these plans consider arrangements for prevention, mitigation, preparedness andrecovery, as well as response. However, over the last ten years substantial progress has been made inestablishing the role of resilience in sustainable development. Multiple case studies around the world reveallinks between attributes of resilience and the capacity of complex systems to absorb disturbance while stillbeing able to maintain a certain level of functioning. Building on emergency planning experience, there is aneed to focus more on action-based resilience planning to strengthen local capacity and capability, withgreater emphasis on community engagement and a better understanding of the diversity, needs, strengthsand vulnerabilities within communities. Floods do not impact everyone in the same way. It is clear that theproblems associated with sustainable human wellbeing in calls for a paradigm shift. Use of resilience as anappropriate matrix for investigation arises from the integral consideration of overlap between: (a) physicalenvironment (built and natural); (b) social dynamics; (c) metabolic flows; and (d) governance networks. Thispaper provides an original systems framework for quantification of resilience. The framework is based onthe definition of resilience as the ability of physical and social systems to absorb disturbance while stillbeing able to continue functioning. The disturbance depends on spatial and temporal perspectives anddirect interaction between impacts of disturbance (social, health, economic, and other) and adaptivecapacity of the system to absorb disturbance.
Coastal Cities at Risk: Aspects of Vulnerability and Resilience for Vancouver, Canada (PAP014998) - Full Paper
Author(s): Deborah Harford
Keywords: Flooding, climate change, sea-level rise
Subject: Flood risk management in mega cities
Abstract:
Extreme weather events have always been part of life in Canada, a rugged and vast countrywith enormous variations in geography and climate, from mountains to desert, to prairies to coasts; however,climate change is continually elevating the severity and frequency of the floods, storms and droughts thatCanadians have to weather. Current and projected impacts are driving governments at all levels to developpolicies and plans designed to reduce the vulnerability of communities and industry sectors and strengthentheir resilience, or capacity to cope with weather-related challenges. Of these, flooding has become thebiggest issue, representing the greatest source of insurance claims in Canada in the past few years ascatastrophic events become more common and infrastructure damage increases.
Vulnerability of East Iran Railway Against Floods (PAP015003) - Full Paper
Keywords: Railway, Flood, Dasht-eLut, Dareh-Angir, Iran
Subject: Flood risk management in mega cities
Abstract:
Railways of Iran especially in arid regions has been damaged of flooding recently. Most of the flood damages were happened on the bridges railway. The main reason can be found in the context of changes in riverbed, sudden heavy rainfall, and coarse sediment. Dasht-e Lut and Dareh-Angir basins in the East of Iran are flat and covered by Salt land that the railway network goes through the north of the area. Length of Railway in the study area is 220.13 km and areas of catchments are 8641.27 Square kilometers. There are a lot of watercourses. Due to the abundance of coarse sediment and flatness, the streams are changing their bed in this area. Thus, more bridges are prone to flooding and runoff. The goal of this research is to assess the railway vulnerability of flood. Data sources were used in the research consisted of two parts: the first part of the data is international Database and the second is the data from 1:25000 topographic and elevation data of Aster images. They have been replaced to increase the spatial resolution of these data. Also 23 samples were taken of sediment under bridges. This research was conducted in two stages, in the first stage a Surface Tank Model, of a set Distributed hydrological modeling, was used in Integrated Flood Analysis System (IFAS) software. The model consists of a surface reservoir to surface precipitation, the average flow velocity and infiltration flow. The second phase Indian Council of Agriculture Research (I.C.A.R) model has been used to evaluate the results. The IFAS results showed that 70 percent of the railway between Robatposhtbadam to Khonj stations, Jandagh to Chadormaloo and Chahmohammadu and also part of Raml to Jandagh which the whole railway 220.13 kilometers faced to flooding and runoff.
Association of Landslides in the City of Blumenau With Accumulated Rainfall in the Region in 2013 Using Logistic Regression (PAP015022) - Full Paper
Keywords: rainfall, landslides, logistic regression
Subject: Land use and Floods, landslides and erosion
Abstract:
Landslide is a relevant natural disaster and the cause of significant economic and life losses worldwide. The understanding of the physical mechanisms responsible for a landslide event has thus practical importance to establish the most vulnerable regions and to develop control measures such as alert systems. Qualitatively, literature has shown that cumulative rainfall plays a significant role on landslide events, with heavy rainfalls associated with a higher chance of slope instability. This study investigates and develops a model to associate the likelihood of landslides in the city of Blumenau with the accumulated rainfall in the region. A logistic regression is proposed to establish a model to the probability of a landslide event occurring as a function of the previous rainfall. The results reveal that the accumulated rainfall for the previous 24 hours tends to be the most relevant variable to predict the probability of a landslide event in Blumenau, with a threshold value of roughly 50 mm leading to probabilities above 50%.
Two Dimensional Hydrodynamic Simulation of the Olho D'água Lagoon, Jaboatão Dos Guararapes (Pe) (PAP015036) - Full Paper
Keywords: Hydrodynamic Simulation, MIKE FLOOD, Flood maps, Olho d'Água Lake
Subject: Land use and Floods, landslides and erosion
Abstract:
The objective is to verify the influence of the evolutionary process of unplanned urbanization, caused by poor planning and land use, on the natural dynamics of storm water runoff in areas susceptible to flooding in the watershed of the Olho d'Água Lagoon in Jaboatão de Guararapes - PE. This study was part of the Sustainable Development Plan for the Olho d'Água Lagoon. The MIKE FLOOD simulation system was used as the primary technology in hydrodynamic analyses of 4 scenarios, proposed from structural interventions defined by experts and connoisseurs of local problems. Some of the proposed solutions consider future projects and civil works. The results of simulated scenarios and the solution adopted under the project are also presented.
Cost Optimal River Dike Design Using Probabilistic Methods (PAP015037) - Full Paper
Keywords: River dike, Optimization, Probabilistic design, Cross-section, Failure probability
Subject: Floods in a changing climate
Abstract:
This research focuses on the optimization of river dikes using probabilistic methods. Its aimis to develop a generic method that automatically estimates the failure probabilities of many river dikecross-sections and gives the one with the least cost, taking into account the boundary conditions and therequirements that are set by the user. Even though there are many ways that may provoke the dikefailure, the literature study showed that the failure mechanisms that contribute most to the failure of thetypical Dutch river dikes are overflowing, piping and inner slope stability. Based on these, the mostimportant design variables of the dike cross-section dimensions are set and following probabilistic designmethods, the probability of failure of many different dike cross-sections is estimated taking into accountthe abovementioned failure mechanisms. Different cross-section configurations may all comply with a settarget probability of failure. Of these, the cross-section that results in the lowest cost is considered theoptimal. This approach is applied to several representative dikes, each of which gives a different optimaldesign, depending on the local boundary conditions. The method shows that the use of probabilisticoptimization gives more cost-efficient designs than the traditional partial safety factor designs.
Assessment of a Real-Time Flood Forecasting at the Doce River Basin: Summer 2013 Event (PAP015040) - Full Paper
Keywords: Real-time forecasting, Flood, Doce River basin, CPRM
Subject: Flood forecasting and early warning systems
Abstract:
The Geological Survey of Brazil- CPRM manages a flood warning system in the Doce riverbasin, which is located in Southeastern Brazil between the states of Minas Gerais (MG) and EspíritoSanto (ES). In summer of 2013 the worst flood that happened was on city of Colatina-ES. This townsuffered the second greatest flood in the recorded history. It was observed that the active atmosphericevents in this period were SACZ (South Atlantic Convergence Zone) and HCZ (Humidity ConvergenceZone). The study of the rainfall in this basin has shown that in some places it rained four times more thanexpected, such as the region near the city of Rio Bananal, which registered an accumulated rainfall of942mm for December 2013. The historical average (1977-2006), according to CPRM (2014), for thisregion is 206 mm of rain for the month of December, so it rained 457% of expected rainfall. The RioBananal monitoring station, located in this city, recorded a rainfall of 280mm in just one day. During thisperiod, 79 hydrological warning bulletins were issued by CPRM. For the real time forecast in Colatina citywas used a discharge-discharge model, which provides a pretty accurate level of the river with six hoursin advance. The data used as input in the model comes from an automatic telemetric station. The RioDoce basin system warning completes 17 years of operation in this rainy season of 2013/2014 and it hasbeen crucial in the flood warning for cities monitored, minimizing the negative impacts of floods duringcritical events.
Let Me Be Learned: Decision Support Aiding Public Participation (PAP015041) - Full Paper
Author(s): Raymond Laine and Chris Cook
Keywords: EDSS, Decision Support, Flood Risk Management, Public Participation
Subject: Flood resilient societies through community preparedness
Abstract:
With best practice floodplain management processes rightly emphasising the need for a collaborative, transparent and inclusive approach to improve community resilience, this paper presents a new Engagement Decision Support System (EDSS) as a mechanism to assist in this process. This paper will explore the need, theory and development of a floodplain management EDSS and present trial results, where the tool has been successfully utilised for three catchments in New South Wales, Australia. The results from these trials, indicate that a well-structured, engagement focused decision support system can provide a mechanism for and empower stakeholders (community members, councillors, developers, planners, engineers etc.) to learn about, prioritise and make informed decisions about floodplain management options for their local catchment in a transparent objective facilitated process.
Generalized Tool for Updating Intensity-Duration frequency Curves Under Climate Change (PAP015857) - Full Paper
Keywords: Climate change, IDF Curves, global circulation models
Subject: Urban Floods
Abstract:
This paper presents a web based tool that integrates an user interface (UI) with an efficientmethodology to update the intensity duration frequency curves (IDF) considering the impact of climatechange. IDF curves are frequently used for design of urban drainage, road drainage, flood controlstructures. It is an expedient method to obtain design ietographs and does not require specificknowledge. The assumption is that the IDF used, should properly represents the hydrological conditionsduring the life time of the designed structure. The methodology consists of creating correlation throughspatial disaggregation and the use of transfer function from the historical data observed to the historicalscenarios from the global circulation models (GCM). In this study the statistical relationship between theobserved data and the GCM output is established for the base period. This relationship is applied onfuture period GCM scenarios to generate the updated IDF curves. The application of proposedmethodology and tool is applied at a metrological station located at the city of São Paulo, Brazil. Theresults obtained from the proposed methodology are compared with an existing IDF curves. The GCMmodel used in the analysis was the CanESM2 from Canadian Centre for Climate Modelling and Analysis.The results show an increasing trend of extreme precipitation compared to the IDF adjusted to the mostrecent data available.
Flood Management in Bangkok: Advancing Knowledge and Addressing Challenges (PAP016221) - Full Paper
Keywords: climate change adaptation, disaster risk reduction, coastal flooding, riverine flooding, sea level rise
Subject: Flood resilient societies through community preparedness
Abstract:
The Bangkok Metropolitan Region (BMR) is increasingly at risk from the impacts of climate change. The Southeast Asia region is projected to experience heavier precipitation, increased monsoon-related precipitation extremes, and greater rainfall and wind speed associated with tropical cyclones. In terms of population and assets exposed, Bangkok is projected to be one of the top ten cities globally exposed to the impacts of coastal flooding. Flooding is considered the most critical hazard for the city, both from coastal and inland flooding, with potential for peak river run-off, high tide, and heavy cyclone-associated rainfall to coincide towards the end of the year. Flooding caused by riverine run-off and rainfall is a reoccurring phenomenon, as recently experienced in 2011, when one of the worst flooding events in Thai history caused hundreds of mortalities, a large number of displaced people, and severe economic damage. This paper examines development of a research strategy and presents preliminary findings for assessing the impact of climate change on coastal and inland flooding of the BMR, which forms a central component of the five-year international Canadian-funded Coastal Cities at Risk project. Key challenges included the lack of spatial data, requiring development of creative methodologies for flood mapping and modelling impacts. Coastal flooding was modelled by integrating projected absolute sea level rise, land subsidence, and plate tectonic movement; inland flooding was mapped from multi-year historical radar data; and the utility of a digital elevation model (DEM) derived modified topographic index examined for delineating flood-prone areas. Future research will examine the impact of storm surge, rainfall-runoff modelling, and integrate flood hazard and other data into a system dynamics model to provide measures of city resilience.
Quantifying Resilience to Flooding Among Households and Local Government Units Using System Dynamics: the Case of Metro Manila (PAP016240) - Full Paper
Keywords: System dynamics, Resilience, Flooding, Metro Manila
Subject: Flood resilient societies through community preparedness
Abstract:
System dynamics is a flexible approach for modelling stocks, flows and feedbacks within a system and for tracing behaviors through time. In the context of flood resilience modeling, it can be used to track the loss of system performance due to adverse impacts of flooding at the onset of extreme rainfall, as well as the potential recovery of the system in time due to adaptive measures. A generic system dynamics model for resilience developed by Simonovic and Peck (2013) is adapted to analyze flooding impacts in Metro Manila cities for the socio-economic and organizational sectors. For the socio-economic sector, monetized household assets were selected as the key stock, with the expenditures and damages due to flooding as outflows from the stock, and income and relief/donations as inflows. Complementing this, the organizational sector model mainly tracks the Local Government Unit (LGU) monetized assets and resources. Similarly, damages due to flooding and spending for relief and recovery decrease the stock of resources while inflows from local and external sources (e.g. funds from the national budget or foreign aid) increase the stock. The household and LGU models are tested and used to evaluate potential adaptation scenarios that seek to make resources available for households and LGUs to build resilience.
Con El Agua Al Cuello. Naturalización De Los "Desastres Naturales". Inundaciones En La Ciudad Autónoma De Buenos Aires (2007-2013). (PAP013791) - Abstract Only
Keywords: Inundaciones, Buenos Aires, Impacto Social, Politicas
Subject: Urban Floods
Abstract:
La Ciudad Autónoma de Buenos Aires (CABA) ha sufrido durante el último lustro una serie de inundaciones producidas luego de fuertes lluvias. Diversos barrios, avenidas, calles y desagües fueron desbordados por la fuerza del agua y las dificultades para su escurrimiento. Asimismo cuantiosos han sido los daños sufridos en infraestructura, servicios y especialmente en vidas humanas. En esta ponencia describiremos y analizaremos los impactos sociales de las inundaciones, desde la perspectiva de la Antropología Social; teniendo en cuenta que no se trata de "desastres naturales", tal como desde sectores del gobierno de la CABA tratan de presentar tales eventos, en un sentido de inamovilidad o de inevitabilidad de estos procesos catastróficos, tal como convendría denominarlos, a los fines de incluir un análisis socioeconómico, político y cultural que permita interpretarlos en su totalidad.
The Problem of the Hydraulic Characterisation of Flood Embankment and Its Foundation: An Approach Based on the Use of Piezometers (PAP014312) - Abstract Only
Author(s): annarita pozzato
Keywords: piezometer, permeability test, hydraulic conductivity, anisotropy ratio, numerical modelling
Subject: Urban Floods
Abstract:
The Adige river, the second longest river in Italy, was rectified in the late 19th century by building embankments about seven meters high. The river embankments are generally made of coarse-grained well graded soils but locally may include layers of finer materials. Because the Adige River was a braided river, the soil profile of the embankment foundation along the embankment length is extremely variable. Characterisation of the hydraulic behaviour of the foundation soils, which is critical in the evaluation of the embankment stability, is therefore problematic for these peculiar soil deposits. The paper presents an approach to characterise the hydraulic response of the foundation soils via dual standpipe/cell piezometers. Three case studies were analysed where data were available from manual monitoring in 'open' standpipe piezometers and from automatic monitoring in 'piezopress' cell piezometers. Soils at two different locations having similar grain size distributions and geological setting, which would have been intuitively classified as the 'same' soil, were characterised hydraulically via permeability tests in open standpipe piezometers. These soils showed them to have different hydraulic conductivities up to 3 orders of magnitude. It follows that formulation of typical cross sections for homogenous geological profiles (i.e. based on soil types), which is a common practice in engineering assessment of embankment stability, can be highly misleading. A second aspect of great relevance in the hydraulic response of the embankment is the anisotropy in the hydraulic conductivity of the foundation soils. The paper shows that piezometers can also be used to derive the anisotropy ratio (vertical to horizontal hydraulic conductivity) via back analysis of the pore water pressure recorded by piezometers at different location in the embankment foundation.
A Study on the Features and Criteria of Debris Flow Partially Blocking Big River (PAP014337) - Abstract Only
Author(s): LUI Cuirong and DU Cui
Keywords: debris flow, partially blocking big river, features, criteria
Subject: Land use and Floods, landslides and erosion
Abstract:
The practices of the post-earthquake flood season indicate that debris flow is the most active disaster type, and debris flow blocking river has become a frequent disaster event, thus there is no time to delay the study on the laws of debris flow blocking big river. Aimed at the phenomenon that in the Minjiang River Valley most debris flows partially block the main river in the form of barrier dam, the author conducts the large-scale indoor flume experiment to reproduce the course that the high-density debris flows run into main river when the intersection angle is 90 degrees. The experimental results show that the thrust force of the follow-up debris flow is the major dynamic force driving the debris flow into the main river; The total volume of debris flows has important effects on river blocking, the more total volume, the more serious blocking. In the process of debris flow blocking river, when damming coefficient 'R' increases, velocity of main river firstly increases and then decreases: when R is less than 0.8, very little material of debris flow is lost (washed away), and head-water level increases linearly; When R is more than or equal to 0.8, the serious amount of material of debris flow is lost (washed away), and head-water level increases exponentially. Based on water and sediment dynamic process, as well as the dynamic equation of debris flow at different slopes, the author considers the interaction between barrier dam and the flow of main river, and establishes the formula to calculate the run-out distance of debris flow in main river. In view of the phenomenon that the material erosion is very serious when debris flow blocking big river, the erosion coefficient is obtained according to the test data of flume experiment. On the basis of the formula to work out the total amount of debris flow blocking main river, proposed by ZHOU Bi-fan, the author presents the relevant conditions amended in the light of the erosion coefficient. Eventually, the criteria of debris flow partially blocking big river is set up in terms of the formula of dynamic process and total amount of material.
Research on Urban Flood Situation and Strategy and Policy of Urban Integrated Flood Management in China (PAP014341) - Abstract Only
Author(s): Song Han and Xiaotao Cheng
Keywords: Urban Flood Situation, Urban Integrated Flood Management, Strategy and Policy, Flood Risk Analysis, Ripad Urbanization
Subject: Urban Floods
Abstract:
In recent decade, urban flood situation is becoming more and more serious as China's rapid urbanization. By the end of 2012, China's urban population had accounted for 52.57 percent of the country's total population. However, China's urbanization rate was only 19.39% in 1980 and 36.22% in 2000. China has 661 cities with a municipal people's government, of which 129 cities with urban population more than one million. Since 2006, more than 100 cities in China had been inundated in flood waters every year, in particular, 258 cities inundated in 2010 and 184 cities inundated in 2012. Many field researches were conducted in nine cities of China, representing different regions, different levels of economic development and different hydrogeological conditions. At the same time many important historical documents of urban flood were also reviewed. In this paper, China's urban flood situation was generally introduced, and China's urban flood management problems were intensively analyzed, including the problems of organization and legal system, urban flood control planning, construction management of urban flood control works, and emergency management of urban flood. Subsequently, the research on strategy and policy of China's Urban Integrated Flood Management (UIFM) was carried out based on the domestic and overseas experiences. According to flood risk analysis theory, Risk Triangle consists of three elements which are hazard, exposure and vulnerability. In the study of strategy and policy of UIFM, regulation and control measures, adaptation measures and emergency measures were comprehensively proposed as countermeasures to these three risk elements and a combination of them. The countermeasures mainly include: (1) to increase investment in construction of urban flood control system; (2) to strengthen cooperation among the relevant government departments; (3) to make sustainable planning of urban flood control system; (4) to enhance water and land use management based on risk analysis; (5) to develop scientific flood emergency plans. Moreover, it is necessary to promote "low-impact development" in urban area, and it is urgent to enhance management of underground works and other weak flood control works in flood period. In order to promote strategy and policy of UIFM, several good recommendations were also presented, including: (1) to enhance integrated management of urban and rural area; (2) to improve flood control organization system to adapt rapid urbanization; (3) to raise the public's awareness of flood risk; (4) to ensure stable investment in urban flood control; (5) and to carry out research of UIFM. In this paper, the strategy and policy system of UIFM were well established based on comprehensive risk analysis. A lot of feasible countermeasures and practical recommendations were put forward to ensure steady and rapid development of national economy.
Combating the Challenges of Real-Time Flood Forecasting by Using Physically Based Distributed Hydrological Model for Large River Basin (PAP014342) - Abstract Only
Author(s): Yangbo Chen
Keywords: flood forecasting, distributed hydrological model, parameter calibration
Subject: Flood forecasting and early warning systems
Abstract:
Physically based distributed hydrological models(PBDHM), which grid the studied terrain into very fine cells, thus having the potential to better represent the hydrological processes, and to couple the high resolution radar estimated precipitation, are considered to be able to improve the flood forecast capability, are regarded as the new generation flood forecast models. But there are great challenges in river basin real-time flood forecasting, particularly if the river basin is bigger than 1000km2. The first challenge is the computation efficiency, as the terrain is divided into very fine cells, so the computation resources needed for real-time flood forecasting is awesome, and the general computer and algorithm could not be used. Secondly, how to calibrate the model parameters is also a big challenge as the PBDHMs have too many parameter, and the conventional method of parameter calibration used for lumped model could not be employed directly. Furthermore, there are also uncertainties associated with PBDHMs that need to be addressed. Liuxihe Model is a physically-based distributed hydrological model that divides the studied basin into a number of cells horizontally and three layers vertically. All cells are classified as one of the three types, including hillslope cells, river cells and reservoir cells according to their flow accumulation which have their own properties and model parameters. The saturation excess mechanism is employed to determine the surface runoff while the interflow is calculated using Campbell's equation. The runoff routing is divided into hillslope routing and river routing. In this study, a parallel algorithm is presented for Liuxihe Model simulation, and a shell computation module is coded based on a high performance computer with multi-processors, and the validation results show that it can make the real-time flood forecasting computation at minute scale for the large river basin with a drainage area of 60 thousands km2 at the cell size of 100m. Based on this achievement, a model parameter calibration method by using Particle Swale Optimization is presented and a cloud system for Liuxihe Model is developed and based on deployed at a super fast supercomper installed in the author's university, which is now a public facility for research and development. Several river basins in southern China with drainage areas ranging from several thousands to tens thousands were case studied, and the model parameter were optimized, and several real-time operational flood forecasting system are also developed and have been put into operation, which can couple with the radar estimated precipitation and quantitative precipitation forecasting. The results show that the challenges facing the PBDHMs real-time flood forecasting in large river basins could be conquered.
Responses to Flood Risk in Small Island States: Adaptation to Sea-Level Rise and Climate Change (PAP014343) - Abstract Only
Author(s): Laurens Speelman
Keywords: small island states, sea-level rise, climate change, adaptation, flood protection
Subject: Flood resilient societies through community preparedness
Abstract:
A key impact of climate change for low-lying islands will almost certainly include accelerated coastal erosion and increased flooding from the sea. Emigration and resettlement have often been mentioned as a potential adaptation option to sea-level rise and increased flooding on these islands. Previous studies often focused on calculating the potential number of environmental refugees by projecting physical impacts on coastal societies. However, the response of coastal societies is complex and depends on the interplay between flood risk, sea-level rise, (perceived) risks of both society as well as decision makers, adaptation, and its effects on coastal sediment processes. This research aims to understand the present and future demographics trends and adaptation behaviour in the Republic of Maldives while taking into account the influence of sea-level rise and climate change. Present and historic trends are analysed using historic geographic, environmental, demographic, and socio-economic data. The analysis shows that the most important reasons for migration are related to socio-economic factors such as education and employment. However, the data also shows a clear co-evolution between coastal processes, floods, and adaptive behaviour, such as protection measures and migration, by coastal societies.
A Large Scale Urban Flood Disaster in Algiers (Algeria): November 10th, 2001 (PAP014344) - Abstract Only
Keywords: Floods, Algiers, Vulnerability, resilience, Disaster Management
Subject: Urban Floods
Abstract:
This paper attempts to present the impact of the unexpected floods and debris flow that occurred within the city center of Algiers (capital of Algeria) on November 10, 2001. According to the official reports, this event caused the loss of 712 human lives, injured 350 people and 116 missing. 1800 housing units were damaged, 56 schools, several bridges, roads and public works suffered considerable damage. The streets of the area affected were affected the debris flow and accumulated more than 1000 000 m3 of mud and debris. More than 350 cars were also damaged and several of them and also buses were buried under the debris flow and mud with passengers. Unfortunately, there is a great deficit in ongoing research on how science is used to facilitate social and political decision-making in the context of risk particularly for unexpected disasters. This event has been analyzed in all its facets to learn all from all the deficiencies that contributed to cause the disaster. Naturally, this requires an integrated approach of research and policy-making for all hazards and disciplines. The analysis of this event has allowed us to make first an inventory of the vulnerability factors, as the existence of the catchments, the high density of inhabitants, open spaces, soil cover, topography, the physical vulnerability of buildings, roads and bridges, the vulnerability of public buildings, etc., of the site and environment that contributed to cause the human and economic losses. This analysis has allowed according to the available data to integrate it into the urban design phase or reconstruction phase in the standards and regulations to reduce the risks. For existing and constructed sites, the risk reduction consists in making new decisions to reduce the vulnerability of the environment and enhance the resilience of the population. Recommendations are made for disaster risk reduction for the site affected of Algiers in terms of reducing the vulnerabilities, and reducing risk and curbing human lives and economic losses through sound knowledge-based measures.
Towards Floodable Cities: Floodability as An Alternative Flood Safety Standard (PAP014347) - Abstract Only
Author(s): Kuei-Hsien Liao
Keywords: flood adaptation, floodability, flood hazard mitigation, safety standard, resilience
Subject: Urban Floods
Abstract:
In the face of increasing extreme storms in many regions of the world, flooding is becoming less predictable and less controllable. This has posed a greater challenge in flood hazard mitigation, especially in urban areas. Still prevailing as a mitigation measure, flood control-referring to using engineering structures such as levees, dams, channelization, and drainage pipe system to prevent flooding-has been recognized as an insufficient solution to long-term flood safety. In recent years resilience has emerged as an important subject in flood management. Originated in ecology in Holling (1973), resilience theory suggests that flood control, which is to artificially suppress the inherit system dynamics, could compromise the resilience of a city to floods. Flood resilience is nurtured through adaptation to, not resisting, flooding. In the era of climate change, a paradigm shift from flood control to flood adaptation in flood hazard mitigation is necessary. In this paper I propose a flood safety standard based on flood adaptation, alternative to the protection standard of flood control infrastructure (i.e., protection against X-year flood). The proposed standard is floodability, describing the degree to which a place can be flooded without incurring physical damage and socioeconomic disruption. Floodability is measured by the percentage of floodable lands in a given area, such as an urbanized floodplain. I demonstrate how floodability is estimated with case studies of several densely built-up areas in Singapore and Taiwan. Essentially, floodability is determined by the design of the built environment, i.e., buildings, open spaces, and infrastructure. As a safety standard, floodability addresses the adaptability of the built environment, which is fundamentally different from flood protection standard that addresses the controllability of the river and stormwater. Move towards floodable cities, increasing floodability requires retrofitting existing built environment. This implies that the spatial planning and design profession, including urban planning, landscape architecture, and architecture, needs to take greater responsibility in mitigating flood hazards. Instead of continuing to invest in building new and/or strengthening old flood control infrastructure, government should redirect the resources to flood adaptation measures. According to resilience theory, this is the best policy to ensure survival in an uncertain world of climate change.
End-User Specific Flood Uncertainty Mapping: Effective Map Design From the Perspective of the English Public (PAP014348) - Abstract Only
Author(s): Richard Vause
Keywords: Flood Mapping, Uncertainty, Map Design, End-user specific mapping
Subject: Flood resilient societies through community preparedness
Abstract:
Contemporary flood risk management places an emphasis on the utilisation of flood maps. However, flood mapping exhibits a number of shortcomings; Firstly, despite uncertainty being ubiquitous in flood information and of value in decision making, it is rarely included within flood maps. Secondly, flood map end-users are heterogeneous, possessing different information requirements for their map use and varying levels of understanding the information maps contain. Therefore, more effective map communication can be achieved through the production of end-user specific flood maps. This study addresses such issues by considering end-user specific flood maps that include uncertainty, assessing map design (content and visualisation) to most effectively communicate uncertainty from the perspective of the public. This was achieved through: 1) a review of contemporary approaches to communicating uncertainty within maps; 2) interviews with 12 participants from two English Flood Action Groups to assess the public's map design requirements and preferences; 3) presenting interview findings as flood map design recommendations for the inclusion of uncertainty, with two recommended maps produced. From this, the study found that the participants consider the inclusion of uncertainty information to be of value within flood maps. The greatest range and detail of uncertainty was seen to facilitate the most informed and flexible decision making. Uncertainty information should be visualised in a clear and unique manner that allows distinction from best estimate information. The best estimate flood information is considered the most significant information for map use and map design should reflect this. Such recommendations are joined by a more extensive list of recommendations.
An Integrated Decision Support System for Managing Flood Events in a Complex Reclamation Territory (PAP014350) - Abstract Only
Keywords: flood protection, decision support system, reclamation territory, climate change, warning systems
Subject: Flood forecasting and early warning systems
Abstract:
The Pianura di Ferrara Water Board covers the entire Ferrara province (North Italy) and is delimitated by suspended rivers and by the Adriatic sea. Approximately 50% of the entire territory is below the sea level (- 4 m), while the altimetry of the remaining part, mainly to the west, ranges between 0 m and +6 m (0 ≡ mean sea level). Most of the area is dedicated to farming, however many urban centres with historical monuments, main roads and hospitals are also present and several tourist centres are located along the coastline. The extensive agricultural activity in the area and the environmental protection require a considerable amount of water to be distributed using a channel network for about 7 months per year. However, both hydraulic protection and irrigation are performed through the same intricate channel network and regulated by a great number of control structures. The high vulnerability to flooding of the entire area is currently growing as a consequence of the climatic conditions which are changing, ground subsidence, sea eustasy and reduced absorption capacity of the soil due to general and continuous urban development. The increasing reduction of the safety margin for protection against floods involves structural interventions and operational optimization. In particular, the most recent and important initiative is the project for a modern and advanced Decision Support System (DSS). This system is based on a continuous hydrological rainfall runoff model, which runs in real time, and on a simplified one-dimensional hydraulic scheme for most of the basins and on a full hydraulic one-dimensional model for 5 of them, all fed by continuously updated information. The system provides important information to the decision makers through the estimation of the potential impacts of the current actions carried out on control structures. Future development will allow for analysing the effect of several policies regarding the management of the control structures. In detail, the current system receives in real time rainfall observations both from rain-gauges and the meteorological radar managed by ARPA (Regional Local Authority). Moreover, it uses rainfall forecasts performed by the Limited Area Model which is run by ARPA twice a day. For each elementary basin, the DSS carries out a hydrological and a simplified hydrodinamic simulation, whose results are used to estimate the safety thresholds and when the safety thresholds are forced, the decision makers is immediately alerted. In more detail, in the current version of DSS, the whole network of 5 selected basins is simulated through a full one-dimensional hydraulic model by taking into account the effective state of control structures and pumping stations. The decision makers will define optimal strategy of intervention by observing the DSS results which are currently based on a predefined operational scenarios which considers the actual configuration of all the devices dislocated along the hydraulic network. Furthermore, all the relevant data are available in real time for different Agencies and Organisations involved in flood emergency management in order to minimize damages to the environment and people.
Flood Disaster Losses and Risk Assessment of Coastal City (PAP014352) - Abstract Only
Keywords: flood losses, risk evalution, fuzzy recogition, maximum membership principle, closeness principle
Subject: Flood risk management in mega cities
Abstract:
As a large coastal city in northern China, Tianjin is located in Haihe River Basin tail, has the history reputation of nine river downstream and Important towns at sea, but it also reflects the special position of vulnerability to flooding. In the south,according to the coastal features of flood storage development and the downstream tidal backwater status,established one and two dimensional coupled model to simulate the flood dynamic evolution process in river and flood storage. On the basis of risk population distribution and economic statistics, used flood damage level fuzzy recognition theory and GIS overlay analysis techniques, multi-dimensional assessed the flood damage in accordance with the principle of maximum membership principle and closeness respectively, determined the level of flood damage, objectively assessed the floods scale and severity, which provided as reference for flood prevention and scheduling, disaster relief and flood risk management.
Establishment of Numerical Model for the Simulation of Storm Flooding in Flat River Network Area Considering Polders Distribution: a Case Study of Jiaxing City, China (PAP014355) - Abstract Only
Author(s): Jing Wang and Na Li
Keywords: river network area, polder, flooding, numerical model, hydraulics
Subject: Urban Floods
Abstract:
A numerical model for the simulation of storm flooding in flat river network area with numerous polders is established for the case study area Jiaxing city in China, based on the existing numerical model for urban area which is built on the basis of one and two-dimensional unsteady flow theory and the technique of unstructured and irregular grids. The factors of polders having impacts on spatial and temporal distribution of flooding and water-logging in flat river network area are considered including flood control standard of levees, drainage capacity, as well as operation rules of different polders. Meanwhile, a concept called small water storage surface is put forward to reflect the storage function of small rivers, ponds and lakes to rainfall process inside and outside polders, which is hard to generate in two-dimensional hydraulics models but can't be ignored. According to the real river distribution, the area ratio of small water storage surface for each mesh is abstracted using GIS tools. Using the numerical model, several typical historical rainstorm processes of Jiaxing City in recent years are calculated. The comparison between simulation results and observed or investigated flooding and water-logging distribution shows that the generalization for this area in the model is reasonable, the characteristics of flood movement and inundation distribution under the integrated action of floods in upper reaches, influence of tidal level in lower reaches and complicated operating rules of flood control and drainage projects can be reflected. The simulation results are reliable and can provide support for flood hazard mapping and flood management.
An Gis-Base Mountain Flood Forecasting and Early Warning System in China (PAP014357) - Abstract Only
Keywords: Mountain Flood, Forecasting, Early Warning, GIS-based, distributed hydrologic modeling
Subject: Flood forecasting and early warning systems
Abstract:
China has the most interesting topography with vast mountain ranges that occupied two-thirds of the nation's land. Consequently, mountain floods have been one of the most deadly natural disasters and are taking an increasing roll in claiming lives and causing severe damages each year. In recent years, China has directed its attention to mountain floods and shifted its policy from flood control to flood management with an emphasizing on forecasting and early warning. But the development of a nationwide mountain flood forecasting and early warning system is still under construction and in the pilot stage. This research, utilizing GIS technique, presents the design principles, composition and the module functionality of an automated mountain flood forecasting and warning system based on the advanced distributed hydrologic and hydraulic modeling processes. The methodologies include zoning of sub-basins using DEM data and character abstraction; Unit Hydrograph analysis for ungaged small watershed; database design and construction; software architecture, design, and implementation; and the integration of the flood forecasting, warning and conducting emergency response. Taking a central Province, Henan, as an example, the proposed system is calibrated and validated. The results show that the proposed system will provide constructive information and assist policy makers in a scientific and timely manner in their decision-making process to reduce the casualty and property damage caused by mountain floods.
Innovative Flood Forecasting for Small and Medium Sized Catchments (PAP014359) - Abstract Only
Keywords: Flood forecast, Water budget modeling, Ensemble forecasts, Management options
Subject: Flood forecasting and early warning systems
Abstract:
In 2010 the hydrological modeling system PANTA RHEI was implemented in the Flood Forecast Center of Lower Saxony, Germany. PANTA RHEI is a conceptual water balance model with special program extensions for the use as operational system for ensemble based river flood forecasting. Numerical weather predictions from the National Weather Service (DWD) are incorporated in order to obtain an extended lead time for the river flood forecasts. The Flood Forecast Center now operates several catchment models from lowland areas to lowland mountain range and covers the half of Lower Saxony (20.000 km²). Here larger cities and industrial plants like Volkswagen are areas at risk. All of these catchments comprise intense water resource management measures like reservoirs and detention ponds (dams), bifurcations, culverts and weirs. These structures can operate automatically or can be operated manually with respect to specific orders by water authorities (NLWKN). The implementation and the successful operation of these partially networked hydraulic structures make up one innovative aspect of the forecast model. For the simulation of small and medium sized catchments the average hyrologic response unit (HRU) element size is about 2.5 km². All the HRUs are further subdivided into hydrotops with emphasis on land use. All the basic catchment models were fitted with a focus on both river flood events and long term water budget. The flood forecast models are operated semi-continuously. All important state variables are saved daily and at the end of any simulation. Once stopped, the operation can be continued immediately e.g. for flood forecast simulations or they can be continued at any previously saved date e.g. for recalibration purposes. When continued in forecast mode, the model continues the water balance simulation but switches automatically from observed to forecasted meteorological input data. The model operator may select an ensemble of meteorological forecasts. At the same time an ensemble of operation rules for the hydraulic structures can be determined. The operation will always show deviations between observed and simulated runoff mainly due to uncertainties in the processing of the sparse meteorological input data. These irregular and temporary deviations need to be corrected by the model operator interactively. For this time consuming operation an efficient and innovative concept was developed, that uses a single comprehensive model parameter (M-parameter) to perform temporally interventions into the water balance simulation. The flood forecast models have proven their forecast quality during three winter periods with intense snow influence as well as during extreme thunderstorms in summer. During the flood event in May 2013 in Germany all of the tributaries from smaller and medium size catchments were reproduced highly satisfying and the published river flood forecasts quite reliable. On the other hand the numerical weather predictions still showed quite high variations in the forecasted precipitations heights during the continuation of the flood event.
Evaluating and Improving Urban Drainage Capacities in China (PAP014360) - Abstract Only
Author(s): Hong Wang and Xiaotao Cheng
Keywords: urban floods, drainage capacity, sustainable measures, storm sewer, hydrologic modeling
Subject: Urban Floods
Abstract:
Urban floods are increasingly witnessed in China due to the imbalance between rapid urbanization and outdated structural and non-structural measures in urban drainage and flood risk management. In recent years, China has directed its attention to urban floods and began to shift its urban flood management policies from separating city drainage and fluvial flooding to an integrated, more holistic and sustainable approach indicating a notable progress. But the overall drainage capacities in urban areas still lag behind the modern world. A recent survey shows that the drainage capacities in most Chinese cities are ranging from 1- to 3-year return period based on the conventional Chinese design method. To address urgent challenges of urban floods, pressing demands have arisen for more accurate and feasible approaches to evaluate and improve existing urban drainage systems and move forward to more cost-effective and environmental-harmonious urban drainage nationwide. This research investigates whether the conventional urban drainage design method, widely used in China for over half a century, are appropriate for modern drainage design by examining basic design concepts from rainfall-intensity-frequency estimation, peak runoff calculation to drainage system integration. To facilitate a better understanding of the discrepancy between China's conventional design method and advanced design techniques based on new knowledge and technology, a hypothetical case study is conducted utilizing both conventional Chinese design method and a more detailed hydrologic-hydraulic modeling technique using USEPA's computer program, SWMM. The results show that comparing to the conventional Chinese design method, the capacity of the case-study drainage system increased from a 3-year return period to a 7-year return period using SWMM modeling technique. Aimed to further improve the drainage capacities in Chinese cities, variety of sustainable measures are considered in the hypothetical case study. In general, infiltration measures are utilized to diminish the first 25mm rain; storage measures are implemented to capture the next 25mm rain; gravel-lined or vegetated channels and other waterways are adapted to increase runoff travelling times. After applying various sustainable measures, an existing drainage system, which was estimated to drain a 3-year event by conventional Chinese design method, will be able to sustain a 20-year storm event without replacing large amount of existing sewers.
The Total Volume Runoff Prediction Value During Snowmelt Period and Application to Riparian Forest Management (PAP014361) - Abstract Only
Author(s): hiroki yabe
Keywords: runoff volume, snowmelt, riparian forest management
Subject: Impact of climate change on flood risk
Abstract:
It is necessary to prevent flooding during snowmelt time, there are examples of control of water resources that takes advantage of snowmelt discharge in the watershed, where such discharge constitutes a large proportion of total volume. It is important to estimate the total amount of snowmelt runoff that flows into dams to support the design of measures against floods triggered by rainfall in the snowmelt season and for efficient use of water resources , river environment management. Overall runoff has a significant impact on discharge downstream of dams, such as when flooding is caused by rain falling on a dam that fills up. In relation to the amount and duration of such downstream discharge, it is increased flood risk and occurred water turbidity, influenced wildlife habitats. The total amount of snowmelt inflow is different weather conditions by precipitation (snowfall), such as air temperaturemade , so these future predictions related with climate change is very important. This study attempts to forecast snow water equivalent using meteorological data of past precipitation, temperature, quantity of solar radiation before snow survey. And the total amount of river runoff is estimated besed on the addition meteorological data after snow survey to the actual measurement data of snow water equivalent. The past pattern of river runoff is classified according to the characteristics of precipitation and snow melting. We can reflect on the prediction of the total volume and time series flow of river runoff. It is possible to predicte the total runoff volume only weather data . Therefore ,this model is able to apply to the future precipitation (snowfall) and air temperature due to climate change. It is clarified how to influence by climate change for each basin correspond to the snowfall and snowmelt characteristics.
Parameter Correlation Influence on Failure Probability Estimation for Multi-Functional Flood Defenses (PAP014365) - Abstract Only
Keywords: Defenses, Failure, Multifunctional, Correlation, Stochastic
Subject: Flood risk management in mega cities
Abstract:
Most relevant structural failure mechanisms of flood defenses that can occur during a flood event have been studied trough time by Dutch national authorities and practitioners. The addition of an extra structure to the embankments as a multifunctional approach has also been in the mind of water managers and architects for quite some time already. However, these additional structures can compromise the system safety as their own failure mechanisms could be triggered during a flood event as well. Most failure mechanisms of flood defense and non-flood defense structures, are described by different numerical models that recreate the physical processes experienced for certain load conditions. Geometrical, geotechnical and environmental data is required as input in these models to design and asses the reliability of these constructions. One of the biggest sources of uncertainty for estimating the probability of failure of any structure, comes when selecting the appropriate parameter values and statistical distributions of the input. This means, that the possible correlation of these input must also be taken into account when modeling a certain failure mechanism. At the moment the effects of spatial and temporal correlation of single variables is considered in the reliability analysis of conventional flood defenses. But for the case of multi-functional flood defenses, dependency between 2 different variables might be of great importance as well. The investigation of the possible correlation effects between these parameters is needed as it this dependency may change the outcome of the estimated probability of failure in unknown ways. Correlation is not only the degree of one variable to be able to describe another one but also the behavior in terms of linearity, monotonicity and robustness just to mention some of the most relevant. For example a variable can be more strongly correlated for extreme values than for lower ones even when describing an incremental behavior. Therefore the actual failure probability during an extreme event is bigger than the one estimated if two variables are assumed non correlated. In order to represent this possible relationships between parameters, the implementation of "Copulas" or joint probability distributions implemented during the modeling processes for the different failure mechanisms. With this study it is intended to evaluate the risk of failure of a flood defense with an embedded structure, in a probabilistic manner while taking into account the correlation of variables that in practice are assumed independent. The outcome of this study will help designers and managers to understand which failure mechanisms might increase or reduce their probability of occurrence after embedding infrastructure into the actual flood defenses.
Utilization of Multiple Radar Observation Into Real-Time Flood Forecasting (PAP014367) - Abstract Only
Keywords: weather radar, flood forecasting, distributed hydrologic model
Subject: Impact of climate change on flood risk
Abstract:
This study describes an example of a real-time flood prediction system in Japan, built on a distributed hydrologic model using radar-estimated rainfall data, and a series of procedures for improving the forecast accuracy. This real-time flood prediction system is currently operational for the Yodo River basin (7,281 km2) in Japan, and a distributed hydrologic model is utilized in it. Precipitation input for the hydrologic model is provided by a composite of data from C-band (5 cm wave length) weather radar estimation and the AMeDAS (Automated Meteorological Data Acquisition System) observation, which has 2.5 km of spatial and 10 minutes of temporal resolutions. The real-time flood prediction system is currently being upgraded to improve its forecasting accuracy with the utilization of new input data. The new precipitation input data is estimated by using multiple X-band (3 cm wave length) polarimetric radars, which have just been released in Japan for operational testing. This study provides a series of utilization procedures for the new input data, data quality checking, system modification, and evaluation of forecast accuracy. First of all, the accuracy of the X-band radar observation was determined by comparing its results with the rainfall intensities as observed by ground gauge stations. It was also compared with conventional C-band radar observation. The rainfall information from the new radar network was then provided to a distributed hydrologic model to simulate river discharges. The simulated river discharges were evaluated again using the observed river discharge to estimate the applicability of the new observation network in the context of operations regarding flood forecasting.
Improving the Us Army Corps of Engineers' Contribution to Flood Risk Management (PAP014371) - Abstract Only
Author(s): Paul Scodari
Keywords: flood hazard reduction, risk informed, cost responsible
Subject: Urban Floods
Abstract:
The U.S. Army Corps of Engineers (USACE) is the principal U.S. federal agency responsible for planning and constructing flood and coastal storm damage reduction (F&CSDR) infrastructure, and for managing part of that built infrastructure. Historically, the F&CSDR program with its focus on flood hazard reduction was viewed as the centerpiece of federal responsibility for flood damage reduction; however, the inflation-adjusted federal budget for F&CSDR has fallen significantly over time. As the F&CSDR budget fell, the National Flood Insurance Program (NFIP) was implemented and grew in scope and importance. Today, more than 20,000 communities participate in the NFIP, which emphasizes the responsibility of communities (local governments) to reduce flood risk through land use regulation, and the responsibility of individuals (households and businesses) to manage their residual risk by purchasing flood insurance. Looking ahead, and recognizing these changing circumstances, the USACE is now embracing the need for "shared responsibility" in flood risk management. This paper presents the results of a USACE study to investigate policy and program changes that would allow the USACE to be more effective in sharing responsibility for flood risk management decision making. The report proposes a conceptual framework calling for "risk informed and cost responsible" (RICR) decision-making by communities and individuals. A similar a RICR-based policy framework was first articulated decades ago in a seminal report by a United States federal task force chaired by Gilbert White. To assure that communities and individuals are fully risk informed requires that they: 1) have access to the same information about the likelihood and consequences of flooding as that available to technical experts; 2) have access to information on actions they could take to reduce risk and manage residual risk, and; 3) understand the current capacity of federal and non-federal programs to provide pre-flood risk reduction and management assistance as well as post-flood assistance. Cost responsible choices are defined in this report as choices that comply with the existing legal and regulatory regimes in place at the time that the choices are made, which recognizes that the rules that establish cost responsibility may allow for the transfer of some share of the financial, risk, or environmental costs from communities and individuals to others. The RICR framework is used to develop recommendations to make shared responsibility an operationally meaningful policy objective. The recommendations fall into two areas. One area focuses on what the USACE can do to increase the public's understanding of current and future flood risk, especially in places where the USACE has constructed F&CSDR projects in the past. A second area includes recommendations for making the most cost-effective use of a limited USACE budget while promoting cost responsible decisions by communities and individuals related to floodplain land use and the adoption of risk reduction and residual risk management actions.
The Economic-Wide Consequences of Large-Scale Floods. An Application of a European Interregional Input-Output Model (PAP014372) - Abstract Only
Keywords: Indirect losses, Disaster modeling, Large-scale floods, Flood risk, European
Subject: Flood risk management in mega cities
Abstract:
In recent history, flooding of both river and coastal systems is the most frequent and damaging natural hazard. Besides large economic losses within the flooded regions, surrounding non-flooded regions can endure economic losses as well. As a result of these extended regional linkages, a comprehensive risk assessment is required to understand which impacts flooding may cause to the economy as a whole. In this paper, we make first steps with applying a methodology consisting of a hybrid interregional input-output model to assess the economic consequences of large-scale floods for the European economy. The proposed methodology consists of multiple steps. First, a direct loss assessment is conducted in several flood-prone regions throughout Europe, based on simulated floods and past flood experiences. Second, the direct losses in capital and labor are translated into the loss in production per sector. Third, the recovery of this production shock is modeled using a hybrid interregional input-output model, combining non-linear programming and input-output modelling. This combination makes it possible to find (1) the possible production losses in the affected regions and other European regions, (2) the required production in Europe to satisfy additional reconstruction demands from the affected regions and (3) the required production in other regions that is necessary to take over lost production in the affected region. Consequently, when knowing how much production is lost (or gained) in each region, the economic consequences can be assessed. Finally, the model outcome is loss estimation expressed in terms of expected annual damage. To assess these consequences, interregional supply and use tables are used, consisting of 256 different European NUTS2 regions. This data makes it possible to model the indirect losses for both the affected region and the rest of Europe in detail. Results show that regions outside the affected area can have benefits or losses, depending on the economic relation with the affected region. Consequently, depending on the size of the flood, the overall consequences for Europe can both be positive and negative. This study shows the large potential of interregional modelling and the added value of combining different economic loss estimation approaches into an integrative framework.
Flood Risk Management in the United States Under Presidential Policy Directive 8 (PAP014373) - Abstract Only
Keywords: flood risk management, national framework, disaster management
Subject: Flood resilient societies through community preparedness
Abstract:
In March of 2011 President Barak Obama released Presidential Policy Directive (PPD-8): National Preparedness. This directive established a new framework for national preparedness, including disaster management, across the Federal government. The overall goal of PPD-8 was to "strengthen the security and resilience of the United States through systematic preparation for the threats that pose the greatest risk to the security of the Nation, including acts of terrorism, cyber attacks, pandemics, and catastrophic natural disasters." PPD-8 called for the development of a national preparedness goal to identify core capabilities required for preparedness as well as a national preparedness system in order to guide and track activities that enable the achievement of the Nation's goals. Five national planning frameworks and Federal interagency operational plans were also called for in PPD-8 to identify the roles and responsibilities of those Federal agencies with roles and responsibilities in the five mission areas of preparedness (Prevention, Protection, Mitigation, Response, and Recovery). The Federal agencies involved in flood risk management have been involved in the development and execution of the Mitigation, Response, and Recovery frameworks and operational plans. These frameworks assign roles and responsibilities to each of the participating agencies for each stage of flood risk management and improve the definition of relationships between the agencies involved. This has improved Federal leadership in flood risk management, and other natural disaster management, in partnership with state and local government agencies, the private sector, and other partners. Changes in the structure of and approach to Federal flood risk management due to PPD-8 and each of these frameworks will be discussed in detail in this paper. Changes in the understanding of mitigation of flood risk due to the National Mitigation Framework in particular will be discussed. Further, examples of implementation of these frameworks, such as for Superstorm Sandy, will be provided and analyzed.
Household Responses to Extreme Flash Flooding: a Case Study From North Yorkshire, England (PAP014377) - Abstract Only
Author(s): Jonathan Hopkins
Keywords: Flash flood, Climate warming, Response, Mitigation, Perception
Subject: Flood resilient societies through community preparedness
Abstract:
Flash floods are a dangerous, unpredictable and damaging hazard which pose a growing threat to communities as a result of climatic warming. Within the UK (and in other countries within Europe), policy changes have led to the public taking on more responsibility for managing flood risks, as the limitations and expense of flood defences have become apparent. Despite this, there is evidence that property-level responses to flood events are low within the UK (e.g. Harries, 2012). A greater understanding of household-level responses to flash floods, and the hazard perceptions of residents affected by flash flooding, are therefore particularly important. This paper presents the findings of mixed methods research which took place within flash flood-affected communities in North Yorkshire, England. A major flood caused severe damage and disruption in Helmsley and upper Ryedale in June 2005. An integration of qualitative (interview) and quantitative (questionnaire survey) data analyses shows that experience of a flash flood does not necessary lead to increased risk perception, or the uptake of significant property-level mitigation measures. Residents' knowledge of flood warning and information services was found to be low. Increased awareness of river levels, rainfall, weather forecasts and low-cost measures were the most common responses to flash flooding. Experience of recent, frequent floods was a key factor associated with increased flood risk perception and some responses to flash flooding. Where a flash flood is seen as a one-off event, in the context of local residents' knowledge and awareness of past flood events (and hydrological records of high flow events), significant responses to the flood may not occur. Furthermore, despite widespread perceptions of increasing summer rainfall and more frequent heavy rainfall, residents were more likely to relate flood risk to the poor maintenance of rivers, rather than climate change. Other factors associated with responses to flash flooding include personal attitudes, demographic factors and experience with flash flooding. It is clearly unreasonable for governments to expect the public to spend money to protect themselves from events which they do not expect to occur again. Increased awareness of the local environment is, however, a useful response to flash flooding. There may be potential to facilitate the collection and distribution of local knowledge about past flood events, following the 'flood histories' and 'sustainable flood memory' approach of McEwen et al. (2012), in order to increase the awareness of local flood risks. Further research into the ways that the public respond to flash floods is essential, so that authorities can improve strategies to manage and respond to these events. Key references: Harries, T. (2012). Why Most 'At-Risk' Homeowners Do Not Protect Their Homes from Flooding. In J. Lamond., Booth, C., Hammond, F., & Proverbs, D. (Eds.), Flood Hazards: Impacts and Responses for the Built Environment (pp 327-341). Boca Raton, FL: CRC Press. McEwen et al. (2012, July). Flood histories, flood memories and informal flood knowledge in the development of community resilience to future flood risk. Paper presented at British Hydrological Society Eleventh National Symposium, Hydrology for a changing World, Dundee. http://www.hydrology.org.uk/assets/2012%20papers/McEwen_34.pdf.
Impact of Extreme Rainfall and Earthquake Events on Waterfront Landslide (PAP014380) - Abstract Only
Author(s): Bin He
Keywords: waterfront, landslide, heavy rainfall
Subject: Land use and Floods, landslides and erosion
Abstract:
Waterfront is the land area alongside a body of water (ocean, river, lake), such as a harbor, dockyard, riverbank, etc. It is well known that a majority of landslides occurred in waterfront area during heavy rainfall and earthquakes. This type of landslide causes tremendous disaster to riverbank, port and industrial facilities. However, little attention has been paid to geotechnical issues arising from what might be termed "Waterfront landslide", which is a phenomenon in between the terrestrial slide and submarine slide. It presents the necessity of a new modelling technology for disaster risk preparedness which simulates initiation and motion of waterfront landslide. In this paper, the features and problems related to the waterfront landslide will be reviewed. The simulation model LS-RAPID, which was developed from the geotechnical model for the motion of landslides and new knowledge obtained from a series of new dynamic loading ring shear apparatus, will be introduced. The waterfront landslides are simulated for several cases of imaginary simple slopes. The performance of each process in the imaginary simple slopes will be examined under different conditions of earthquake and rainfall. The process of progressive landslide failure and development to a rapid landslide will be visualized in both two dimensions and three dimensions. The preliminary results of a computational study conducted to analyze waterfront landslide for several case studies will be then presented.
Understanding of Large-Scale Flood Processes With a Rainfall-Runoff-Inundation Model (PAP014385) - Abstract Only
Keywords: 2011 Thai Flood, RRI Model, Sensitivity, Delta, Chao Phraya River
Subject: Floods in a changing climate
Abstract:
Understanding large-scale flood processes is essential for flood risk management in a changing climate. In 2011, the Chao Phraya River (CPR) basin in Thailand experienced large-scale flood resulted in the worst economic flood damage in the country. The flooding was induced mainly by unprecedented rainfall from five typhoons and tropical depressions between May and October. The total rainfall in the six months during the monsoon season was approximately 1,400 mm, while previous large-scale floods were caused by a total rainfall of approximately 1,200 mm and the average monsoon-season rainfall in this region is about 1,000 mm. The interpretation of the additional 200 mm of rainfall compared to past events can greatly affect the understanding of the 2011 flood disaster. Without understanding the impact of the rainfall variability on flood runoff and inundation, essential characteristics of the flood disaster may be misinterpreted. In this study, we conducted 52 year-long inundation simulation at the river basin scale. We applied a 2D Rainfall-Runoff-Inundation (RRI) model to the entire CPR basin. After the model validation with river discharges and water levels, remote sensing inundation extents, and peak inundation water depths for 2011, we conducted water balance analysis from the simulation results to investigate the relationship among rainfall, runoff and inundation volumes. The simulation, by taking two major dams into account, found that 131 mm (9%) of the total rainfall (P) 1,400 mm) may have flooded (F) at the peak. The slope of a linear regression between rainfall and flood inundation volume (dF/dP) was 0.25, suggesting that the additional 200 mm of rainfall may have resulted in a 50 mm, or 8.2 billion m3, increase in flood inundation volume. It accounts for more than 60 % of the total storage volume of the largest dam (Bhumibol dam: 13.5 billion m3). On the other hand, the contribution of the two major dams to reducing flood inundation volume was estimated to be 26 mm (4.4 billion m3) for the 2011 event. Hence, the extra 200 mm rainfall, or the additional 8.2 billion m3 of inundation volume, compared to the past large-scale floods, has great impact in the flood magnitude for the CPR basin. Furthermore, estimated elasticity (eF = (dF/F) / (dP/P)) of flood inundation volume to precipitation change is higher (eF ~ 2.9 to 4.2) than that of runoff volume (eR ~ 1.9 to 2.3), indicating that the flood inundation volume is more sensitive than runoff volume for the same change in rainfall amount. The analysis provides an important perspective in terms of climate change vulnerability to flooding. The presented dF/dP and dR/dP should be useful indicators for characterizing how climate change impacts on flooding in particular basins. Moreover, the presented rainfall-runoff-inundation simulation at a river basin scale should be an effective approach for the analysis of flooding including the assessment of climate change.
Worsening Seasonal Flood Situation in the Coastal Megacities of India: Challenges in Urban Management Under a Changing Climate (PAP014389) - Abstract Only
Author(s): Shadananan Nair
Keywords: coastal megacities, India, climate change, urban flood, policy
Subject: Urban Floods
Abstract:
Millions of poor people with low adaptive capacity living in slums and coastal zones of the cities make India highly vulnerable to the impacts of climate change. Extremes in climate together with anthropogenic activities cause severe floods in the coastal megacities Mumbai, Kolkata and Chennai, resulting in casualties and large-scale damage to infrastructure. Uncontrolled growth in urban population due to migration from rural areas and illegal migration from neighbouring countries makes flood management complicated. Indiscriminate encroachment into waterways, inadequate capacity of drains and improper maintenance of the drainage infrastructure creates severe floods in every rainy season. These cities also face threat from the sea level rise, increased wave action and increasing frequency and severity of cyclones. Flooding due to waves and storm surges contaminate the coastal water resources. Rising sea level may further deteriorate it. Destruction of wetlands, paddy fields and canals in and around the cities aggravate the flood conditions. Release of solid wastes into sewage channels results in flash floods, leading to serious environmental and health issues. Coastal flooding creates socio-economic issues such as mass migration to the interior leading to competition and conflict over resources and large investment required for adaptation and impact mitigation. This paper analyses the impact of floods in the coastal megacities of India and critically reviews the current policies and adaptation strategies. Analysis shows an increasing trend in rainfall seasonality and intensity, and proneness to floods. Current measures for the flood impact mitigation and climate change adaptation in Indian cities are poor. National Disaster Management Authority is yet to release guidelines for urban flood management. Climate policy doesn't consider urban water issues seriously. Implementation of regulations such as the coastal zone regulation act often fails because of various administrative, social, political and economic reasons. India needs to develop an appropriate strategy and policy for climate change adaptation and impact mitigation, with special focus on the coastal cities. Suggestions for an appropriate urban policy and flood impact mitigation strategy have been provided, considering the present scenario and possible changes predicted by models.
Water Stage Prediction Using the Coupled Hydraulic and Hydrologic Model and Data Assimilation (PAP014392) - Abstract Only
Keywords: Flood forecasting, Rating curve, Particle filters
Subject: Flood forecasting and early warning systems
Abstract:
It is essential to identify the uncertainty in two factors, model parameters and observation data, for a successful flood forecasting. They affect to other various factors during flood forecasting, which are generally utilizing a hydrologic and a hydraulic model. In many cases, deterministic parameter set and deterministically observed data are utilized in the forecasting models, and the uncertainties of those factors are not considered carefully. Careful combination of model and parameters as well as adopting a sophisticated data assimilation scheme should be consider to avoid unidentified uncertainty in the flood forecasting and improve the accuracy of it. Therefore, we are proposing a comprehensive forecasting system with a coupled hydraulic and hydrologic model with the particle filtering scheme. For the sakes of the connection between a hydrologic and hydraulic model, observation uncertainties included in a rating curve are considered, when the curve is adopted for the hydrologic model calibration and the boundary setting for a hydraulic model. It was evaluated in our previous study to establish a rating curve using a 2D dynamic wave model and particle filters. Based on the analysis of uncertainties of the rating curve, the uncertainties of hydrologic parameters are improved by the sequential update of the water stage at the gauging stations. Moreover, the ensemble discharge predicted by a hydrologic model considering the uncertainties of parameters serve as boundary conditions of a hydraulic model for the water stage prediction. In comparison with an existing method for flood forecasting, the proposed method is able to provide the sequentially updated information about flood stage and to consider the uncertainties included in the rating curve by the coupled system. The proposed method is applied to the areas prone to floods within the Katsura River located in Kyoto, Japan.
A Flexible Adaptive Framework for Decision Making in Design of Multifunctional Flood Defence Structures Under the Condition of Deep Uncertainty (PAP014393) - Abstract Only
Keywords: Flxibility, Decision Making, Deep uncertainty, Multifunctional flood defences
Subject: Flood risk management in mega cities
Abstract:
A large proportion of primary flood defences in the Netherlands do not comply with safety standards and need reinforcement. Often, the land required for reinforcement has to be shared with land development plans resulting in a growing need for integrating flood protection measures and spatial planning interventions. One alternative approach is the concept of "Multi-Functional Flood Defences (MFFD)", where the flood defence has a secondary function in addition to flood protection. Long term planning for MFFD, as a complex and interconnected system is directed by different dynamics that are inherently uncertain in their behaviour. The degree of uncertainty across the myriad of uncertainties varies widely from known quantifiable uncertainties (e.g. model uncertainty) to the so called 'deep uncertainties' defined as known unknowns (e.g. magnitude and rate of climate change) and unknown unknowns (future surprises and shocks) that cannot be quantified and interpreted by probability distributions. Moreover, these uncertainties can result in serious outcomes and consequences on the system performance and its users. This leads to the need to investigate and cope with these uncertainties. To support long term planning for MFFD to more than a few decades into the future while actively dealing with deep uncertainties, the plan should not only achieve the desired targets and outcomes, but it should also be flexible to adaptively respond to unforeseen or unexpected changes. Alternatively, development and planning of MFFD under the condition of deep uncertainty requires a method that acknowledges the dynamic and non-linear behavior of the MFFD system. Whereby, stationary approaches require judgment and prediction about which of the multiple and constantly changing plausible futures of the system may be the most likely. In presence of deep uncertainties, adoption of an iterative, interactive approach provides the analytic framework to think creatively and systematically about the potential future surprises and makes it possible to actively response to them. This can potentially be achieved by adoption of a flexible adaptive decision making frame that appreciates the learning through the time processes and allows the existence of decision points over time. The adopted flexibility-oriented design options (via an incremental design) provide the decision maker with the opportunity, but not the obligation, to take future actions when uncertainties are likely to be reduced or diminished. The approach can accommodate multiple sources of uncertainty via none-probabilistic scenario development. Respectively, this paper describes the flexible adaptive framework developed for decision making and design of MFFD structures. Thereafter, the method is tested in a case study and lesson learned are discussed.
Drawing Flood Risk Map Efficiently Based on Cartographic Data Model (PAP014396) - Abstract Only
Author(s): Xu Mei
Keywords: flood risk maps, cartographic data model, standard, cartographic symbols
Subject: Flood resilient societies through community preparedness
Abstract:
Flood risk maps, which help flood risk management, should display three types of information at least. They are basic geography, hydraulic project and flood risk information. They will be widely used for land-planning, river basin flood control planning, flood control decision, flood insurance, enhancing public awareness of flood risk and so on. They are should be more readable because they will supply services not only for the professional of different field also for the public. For improving the readability of flood risk maps, they should be standard, uniform and authorized. The research and attempt about flood risk maps in our country had been in progress all through the past 30 years, and the flood risk maps of about 90 pilot regions had been finished But the results were all different which behave in three points: nonstandard cartographic symbols which easily lead to wrong interpretation of map, non-uniform style and layout, the other was random map content. These problems are bad for flood risk maps been used effectively. Before large-scale mapping of flood risk began in our country, these problems should be solved. In this paper, a method for drawing flood risk map more effectively will be suggested. The key point is building a prefect cartographic data model. In this model, several related standard will be embedded in. The main content of the model include four aspects as follows: classification and layering of primary map data, coding of each data layer, standard cartographic symbols, and standard style and layout of the map. In the model, standard cartographic symbol contain all the involved data type such as geographic, hydraulic project, flood control engineering, flood risk and so on. Each type of cartographic symbol is made according to the related GB and trade standards. The style and layout are complied with the issued detailed rules of flood risk maps. The results of different regions or different drawer will well satisfied the requirement raised above only if they draw the flood risk map based on the model. And another advantage is the model will help the drawer reducing the workload greatly. The main work they need to do is preparing and dealing with the primary data according to the classification and coding rules set down in the model. Remaining works will be leaved to the model.
Building Three-Levels Management System and Mode for Flood Risk Map Based on Sharing Mechanism (PAP014398) - Abstract Only
Author(s): Xu Mei and Liu Shu
Keywords: flood risk maps, management system and mode, sharing mechanism
Subject: Flood risk management in mega cities
Abstract:
China is one of the most frequent flooding countries. In recent years, our country had transformed the concept and attitude to the flood from 'flood control' into 'flood management'. Flood risk management is the core of flood management. Flood risk maps will display the risk information to decision makers and the public and it will improve scientific decision-making and enhance public awareness of flood risk. So the Flood risk maps will be one of the no-structural infrastructure for flood management. In past 30 years, we have mapped about 90 flood risk regions being pilot. The results are scattered in each river basin commissions. This loose management can't help the flood risk maps being used widely and updated. In our country or in our department, the problem of maximizing the production and despising the management was always existed in past years. This resulted serious waste. According to the plan of MWR, large-scale mapping of flood risk will be launched in the near future, there will be much data and results. How to put these flood risk maps full functioned? It will be realized through the efficient management system and mode. In this paper, a kind of efficient Management system and mode for flood risk maps based on sharing mechanism will be raised and designed. Under the mode, three-levels management system will be built. The basic is province, the second is river basin and the third is national level. All the related data and results will be only saved, updated and managed by each province or river basin commissions themselves. In river basin level and national level system, no data are existed repeatedly. But all the flood risk maps can be shared by every user if authorized. And the other application system can be built based on the flood risk maps services. The most important difference with the traditional management mode is sharing results through services not data supplying. It has many advantages, such as high data safety, distributed saving, economical and concentrated management, opening service and so on. The goal is that all the flood risk maps will be efficiently managed and widely used.
Guiding Principles for Using Ifsar Aerial Survey for Low Cost Flood Mapping (PAP014404) - Abstract Only
Keywords: Flood Hazard Mapping, IfSAR, Hydraulic Modelling, Flood Modelling
Subject: Land use and Floods, landslides and erosion
Abstract:
Over the past 10 years, access to aerial survey (such as LiDAR and photogrammetry) has enabled practitioners to substantially improve the accuracy of flood models and associated flood mapping. The availability of these data is typically resulting in one-dimensional (1D) flood models being replaced by fully two-dimensional (2D) or integrated 1D/2D models. Consequently, there appears to be a greater dependence on access to high resolution, high accuracy aerial survey to be able to assess complex flood behaviour. Acquisition of highly accurate aerial survey such as LiDAR or photogrammetry can be prohibitively expensive for a project and, in some cases, can delay the commissioning of studies until funding is available. In many situations, this fails to meet the needs of flood prone communities, subjecting them to on-going flood risk. Therefore, lower cost alternative datasets, such as IfSAR, are often sought to make the flood mapping process viable. IfSAR data are captured from aircraft flown at high altitude, thus resulting in a lower cost for a given area. The lower cost is directly reflected in reduced accuracy of data, which itself affects the accuracy of the flood modelling. The adage, "any data is better than no data" has a strong place in the debate of whether or not IfSAR is appropriate for flood modelling application. If these lower accuracy data could be used for broadscale flood mapping, there is potential for flood prone areas to be identified earlier. Higher accuracy survey and modelling could then be targeted to specific areas. At the other extreme, some practitioners are actively using IfSAR survey as a basis for flood modelling and subsequent flood mitigation structure design. The risk here is that authorities and practitioners are placing too much confidence in IfSAR data, generating additional risk due to potential failure or under-design of infrastructure. It is imperative that practitioners draw attention to the limitations of flood maps to ensure they are used appropriately and for their intended use. Flood mapping derived from poor data can have serious, and even fatal, consequences. This is particularly relevant for the analysis and design of flood mitigation structures, such as levees. This paper will provide context to, and describe a set of guiding principles that have been developed for the use of different topographic datasets for flood mapping application. The paper identifies the limitations for different types of aerial survey data. It is intended that these guiding principles can be referenced by authorities worldwide when assessing the feasibility of flood mapping or flood mitigation projects. The guiding principles are based upon three case studies (in Australia and Malaysia) where IfSAR, LiDAR and photogrammetric datasets have been used for flood modelling and the resultant flood mapping and modelling output compared.
Application of Unscented Kalman Filter as Data Assimilation Method to Flood Prediction System of River Yoshii (PAP014405) - Abstract Only
Author(s): Kohji Tanaka
Keywords: flood prediction system, data assimilation, particle filter, distributed runoff model, flood forecasting system
Subject: Flood forecasting and early warning systems
Abstract:
The purpose of this study is to estimate the applicability of unscented Kalman filter, which is one of methods to optimize the state valuable in governing equations in order to fit the temporal water surface level from past time to current time. Unscented Kalman filter is a method to optimize the state valuable with using static two order valuable of the observation and the system noise. However particle filter, which is based on the Monte method, is effective to solve the optimization in inverse problem. In this study, we improved the accuracy of water surface level forecast system, which predicts 40km reach from river mouth in River Yoshii, Okayama prefecture in Japan. One dimensional hydrodynamics model was adopted as system equations. Water surface level at downstream and discharge at upstream and downstream were chosen as state variable, which were parameters in governing equations. These state variables were optimized by Unscented Kalman filter in order to fit water surface level at current time. Furthermore predict computation is performed with optimized state variable as the initial condition. The temporally discharges by solving with distributed runoff model was given to the boundary conditions at upstream was given. On the other hands, predicted water surface level before 6 hours was given to the boundary conditions at downstream. We estimated the accuracy of water surface level at 1, 3 and 6 hours after by comparing the predicted water surface level with the observed one. We judged the unscented Kalman filter to be proper as the technique that a flood prediction was available to. Moreover this data assimilation methods can suppose temporal discharges. As a result of having compared the conversion discharges for the observated water level with the estimated discharges, the error understood a certain around 10% of ranges. This technique was shown to be validity from compatibility to observation water level as the technique that was applicable to a flood prediction system.
What If the Dutch Started Worrying About Flood Risk? (PAP014414) - Abstract Only
Keywords: Risk allocation, Efficiency versus equity, Spatial computable general equilibrium
Subject: Impact of climate change on flood risk
Abstract:
The roles and responsibilities of the public sector in flood risk management are under debate. Partially allocating risk to the private sector can promote individual mitigation behaviour but it can also result in distributional effcts. In this paper we analyse the macroeconomic effcts from a public-private transfer of risk in the Netherlands using a Spatial Computable General Equilibrium model. We find that the a transfer of risk to the private sector leads to an up to 5 percent decrease in capital destruction but only to a negligible decrease in casualties in case of a flood. Long-term impacts from a flood on government finances are reduced by the risk transfer, but our results suggest that there are welfare losses among households residing in risky regions.
Prioritising Watersheds on the Basis of Regional Flood Susceptibility and Vulnerability in Mountainous Areas Through the Use of Indicators (PAP014416) - Abstract Only
Keywords: Susceptibility to floods, Vulnerability, Mountainous areas, Indicators, Morphometry
Subject: Floods in a changing climate
Abstract:
Settlements in peri-urban areas of many cities in mountainous areas such as in the Andes are susceptible to hazards such as flash floods and debris flows. Additionally these settlements are in many cases informal and thus vulnerable to such hazards, resulting in significant risk. Such watersheds are often quiet small, and generally there is little or no information from gauges to help characterise risk. To help identify watersheds in which flood management measures are to be targeted, a rapid assessment of risk is required. In this paper a novel approach is presented where indicators of susceptibility and vulnerability to flash floods were used to prioritise 106 mountain watersheds in Bogotá (Colombia). Variables recognised in literature to determine the dominant processes both in susceptibility and vulnerability to flash floods were used to construct the indicators. Susceptibility was considered to increase with flashiness and the possibility of debris flow events occurring. This was assessed through the use of an indicator composed of a morphometric indicator and a land use indicator. The former was constructed using morphological variables recognised in literature to significantly influence flashiness and occurrence of debris flows; the latter was constructed in terms of percentage of vegetation cover, urban area and bare soil. The morphometric indicator was compared with the results of a debris flow propagation algorithm to assess its capacity in identifying the morphological conditions of a watershed that make it able to transport debris flows. Propagation was carried out through the use of the Modified Single Flow Direction algorithm, following previous identification of source areas by applying thresholds identified in the area-slope curve of the watersheds and empirical thresholds. Results show that the morphometric variables can be grouped in four categories: size, shape, hypsometry and energy, with the energy the component found to best explain the capability of the watershed to transport debris flows. The combination of the morphometric and land use indicators resulted in a susceptibility indicator that was compared with the available records of past floods in the area. This showed that the use of the land use indicator significantly improves the susceptibility assessment. Vulnerability was assessed in terms of indicators representing physical exposure, fragility of the socio-economic system and lack of resilience to cope and recover. Principal component analysis was subsequently applied to reduce variables and provide a representation of each of their facets by a component. This resulted in a composite indicator of susceptibility and vulnerability for each of the 106 watersheds. The indicator was compared with the history of flash flood damage in the watersheds. Results show that the indicator is useful in applications at regional scales for preliminary assessment to differentiate at spatial level the degree of flood susceptibility and vulnerability. This provides an initial and qualitative risk outlook in the study area and can be used for planning and prioritisation of further more detailed studies.
Land Use and Climate Change Impact on Lake Hydrological Cycle: a Case Study (PAP014417) - Abstract Only
Author(s): Inga Ginfelde
Keywords: land use, hydrological cycle, lake hydrology
Subject: Land use and Floods, landslides and erosion
Abstract:
The monitoring of rivers and lakes hydrological regime has been made during past hundred years. There is strong evidence that there is long term changes of lake hydrological regime caused not only by climate change but also anthropogenic factors. Lake Usma in Latvia is unique with hundred years' old natural reserve and Natura2000 nature protection areas in one part of lake and developing tourism industry in other coast of lake. During last ninety years the water level of Lake Usma increased for approximately one meter, which caused coast erosion, flood risk and changed soil ground water level in large territories around it. To find sustainable management solution for Lake Usma there is need to understand causes of hydrological cycle changes. In this research work are analyzed Lake Usma water level cycle changes since year 1926 in annually, monthly, daily and hourly scales, to find natural and anthropogenic factors impacting Lake Usma hydrological cycle. The result shows significant impact of natural and anthropogenic factors. The significant climate impact started since late 80ties. However during last sixty years there are significant anthropogenic impact in case by land reclamation measures in Lake Usma basin and hydro technical buildings downstream of Usma Lake.
Multi Source Data Fusion Approach for Precise Flood Forecasting (PAP014419) - Abstract Only
Keywords: Data Fusion, Multi Source Data, Flood Forecasting
Subject: Flood forecasting and early warning systems
Abstract:
Flood, as more important natural water hazards, cause intense human and financial losses. Therefore, one of the main concerns of governmental agencies is flood monitoring and forecasting. Recently the use of multi-source data fusion in to the hydrologic estimation has raised accuracy and precision of forecasting. In this research, the technique of multi-source data fusion is applied to combine information received from different sources of data including CMORPH and TRMM as well as the recording gauges to calibrate real time storms for the purpose of flood forecasting and nowcasting in the Karoun basin in the western part of Iran. A multi-source data fusion scheme is used on data sources to determine amount of contribution for each of data sources. The results demonstrate the supremacy of the proposed dynamic approach of data fusion over the conventional approaches.
Prevention as Adaptation Measure Against Natural Disasters in a Non-Cooperative Game (PAP014421) - Abstract Only
Author(s): Oliver Fiala
Keywords: Adaptation, Prevention, Game theory
Subject: Urban Floods
Abstract:
After an increasing number of floods in different countries of Europe in the last years, the discussion about more effective adaption measures is of relevance to the present situation. Prevention measures have not only a damage-reducing effect for the region which enforce it, but also different effects on neighborly regions which can be seen as an externality. These externalities are analyzed in the present paper. We model a non-cooperative and simultaneous game where two actors decide about prevention measures and analyze possible equilibriums in dependence from the form of externality of the prevention measure. The individual decision as well as its influence on the other actor's effort crucially depends on the underlying externality of the prevention. Both positive and negative impacts of one's prevention effort on the prevention decision of the others are possible. In the case of a positive externality the prevention effort of one region provides particular protection for the other. In contrast, there is a negative externality, if the prevention effort of one individual increases losses of others. Dominant strategies and possible equilibriums are represented analytically and explained dependent on the form of the externality of the prevention.
Social Assessment to Housing Reconstruction Plan in Chile. the Case of Dichato Bay (PAP014423) - Abstract Only
Keywords: Flood, Social Assessment, Housing reconstruction plan, social perception
Subject: Urban Floods
Abstract:
After the catastrophe that affected Chile in 2010 a housing reconstruction plan, promoted by the national government, has been its focus to build a new and safe house, especially for improve the social vulnerability and expose to the flood risk. This research asses the satisfaction level of victims of tsunami flooded, linked with their social expectation and the comparison with the real actions implemented by the government. Regarding to data collection, we used the deep interview applied in the residents affected by tsunami and benefit with the housing reconstruction plan. The main result shows agree and disagree levels, that the community has respect the plan implemented, and we identified the main factors that the housing reconstruction plan did not include, according with their social perception.
Motivating the Public to Take Actions to Reduce Flood Risk - Best Practices (PAP014426) - Abstract Only
Keywords: risk communication, public education, flood mitigation
Subject: Flood resilient societies through community preparedness
Abstract:
Federal agencies in the United States, particularly the U.S. Army Corps of Engineers and the Federal Emergency Management Agency, communicate flood risk to their publics in order to increase awareness, build shared responsibility for the risk, and motivate communities and individuals to take steps to reduce their risk. Public education has long been used as a tool to influence behavior because it is perceived as relatively easy to execute; however, it is not necessarily effective in quickly motivating action. The other primary approaches for reducing risk include changing the risk through engineering infrastructure, or changing the rules of a system through changing zoning or mortgage laws. Such approaches still require public acceptability to implement, which means that public education continues to be an essential component of community-centered change. Current social psychology research provides many recommendations for how to conduct public education campaigns most effectively. For example, research shows that educating about the level of risk does not correlate to taking action. Factual information can be important for establishing a baseline of awareness, but can also trigger cognitive decision paralysis. Instead, sharing vivid descriptions of a past or potential flood event, or hearing testimonials from survivors of flood events, provide emotional triggers that instill motivation to act. However, building emotional connection is only the first step. For action to result, the individual or community still needs to know specifically what actions can be taken, how to prioritize those which are most effective for their situation, and how to move forward in implementing them. This information is delivered most effectively when the content is consistent and delivered from multiple sources, through multiple media channels, and over a considerable length of time. Therefore, agencies will be more effective if they partner and develop joint messages and coordinate on outreach programs. Public education remains an important tool for changing the status quo for flood risk management in the United States. Educators just need to have realistic expectations of its potential impacts, and to utilize best practices for developing key messages and engaging with the public.
High Speed Flood Modelling to Enhance Flood Forecasts and Improve Communication of Flood Warnings (PAP014430) - Abstract Only
Keywords: Flood Warning, Flood Forecasting, Hydraulic Modelling, Flood Response
Subject: Flood forecasting and early warning systems
Abstract:
The 'traditional' approach to floodplain management has been to artificially modify the passage of floodwaters through a catchment via structural means (e.g. levees or floodways) in an attempt to reduce the frequency and severity of flooding at certain locations within the catchment. Changes to floodplain management practices have seen a progressive transition from this structural approach towards a more planning and response based approach. There is increasing recognition that the traditional structural approach rarely removes the flood hazard altogether, and that floods will continue to occur across floodplains. Empowering communities to become more aware of, and resilient to, floods is now widely regarded as the most effective way to reduce the economic and social impacts of flooding. Flood forecasting and flood warning are two of the most effective flood management measures for reducing harm to the public and damage to property. In many countries throughout the world, government authorities are responsible for flood forecasting, often at a national level. Forecasts are presented to the community as a flood warning, typically with information limited to the expected peak level and time of occurrence. To most in the community, such predicted levels have little meaning and the consequences are not understood. Until now, the use of hydraulic models for flood forecasting has been limited to using simplified one-dimensional models, primarily due to computational speed and model stability. Recent advances in flood modelling software have seen the release of some two-dimensional hydraulic models that can simulate at an exceptional speed and reliability. Whilst this software has value to floodplain managers who need to model large areas (even on a country scale), the implications for flood forecasting and warning are twofold: 1. The computational speed now enables these models to be used to enhance flood forecasts; and 2. The use of two-dimensional hydraulic modelling allows the lateral flood extents and localised flood behaviour to be defined. The effect of the latter is that authorities will have the ability to provide more effective, targeted, flood warnings to the community, thus empowering the community to protect themselves and their belongings. Likewise, flood response personnel will be able to plan for and target areas where assistance is most needed. This paper includes two case studies where two-dimensional hydraulic models are used to enhance flood forecasts and have provided added value to flood warnings.
Flood Risk Analysis in Western Saudi Arabia (PAP014501) - Abstract Only
Author(s): Ali M. Subyani
Keywords: SCS hydrographs, Maximum Daily Rainfall, Floods, Western Saudi Arabia
Subject: Urban Floods
Abstract:
Western region of Saudi Arabia, is characterized by extremely arid conditions. This area is also subject to flash flooding that occurs immediately after heavy, short rainstorms, resulting in loss of life, infrastructure, and property. This valuable and important area requires the development of sustainable structures that can withstand such flooding. In this study, a runoff model adapted from the Soil Conservation Service was built for the catchment of five selected ungauged dry wadis in the study area. Data from 16 rain gauges that have been recording the annual maximum daily rainfall for over 30 year records were analyzed and used to derive the Gumbel extreme value distribution for 25-yr, 50-yr and 100-yr return periods. Hydrographs for different return periods were drawn. Regional maps of maximum probable precipitation and probable maximum flood were also produced for the study area. These results will be helpful when decisions are made regarding the planning, management, operation, and maintenance of flood occurrences in this important area.
Using Agent-Based Modelling With Inundation Predictions to Enhance the Resilience of Small Businesses (PAP014521) - Abstract Only
Keywords: agent-based, urban flood, linking, building
Subject: Urban Floods
Abstract:
Flooding affects different individuals, communities and organisation in different ways. All of these can suffer either directly or indirectly due to the impact on small businesses. These businesses are often vital to a community's well-being and economic success, but are also vulnerable due to the lack of time and resources to make themselves resilient to flooding. The UK's Engineering and Physical Sciences Research Council is funding a project on innovative solutions to flood risk and in this research is being carried out to understand and improve business response to and preparedness for flood events in urban areas. To achieve this aim, agent based modelling and inundation simulation are being combined to study organisational business continuity over time periods beyond the immediate flood impact (i.e. days rather than hours or minutes). This paper reports on the development of the virtual geographic environment (VGE) component of an agent based model along with how this has been combined with inundation modelling to identify businesses affected by flooding in urban areas. The VGE has been developed, using OS MasterMap©, to identify and classify the UK businesses affected by actual and hypothetical flood events. Inundation modelling based on 1D and 2D approaches combined then allows the identification of all flood affected organisations within the geographical area of interest. In the modelling careful attention has been paid to 1D-2D linking and correct representation of buildings in order to allow for the identification of individual properties at risk. Coupling the VGE with inundation predication provides credibility in modelling flood events in urban areas, even those not yet exposed to flooding. A case study of the Lower Don Valley in Sheffield, which was severely affected by flooding in June 2007, is presented leading to the identification and classification of businesses impacted. Further work will focus on the development of intelligent agents to model and simulate businesses during floods and in the aftermath of these events such that changes in their actions and behaviours can be investigated leading to improved operational response in the future.
Delivering and Evaluating Multiple Flood Risk Benefits in Blue-Green Cities (PAP014522) - Abstract Only
Author(s): Nigel Wright and Colin Thorne
Keywords: urban, blue green, resilience, cost benefit
Subject: Urban Floods
Abstract:
In the UK a research consortium has been funded to develop new strategies for managing urban flood risk as part of wider, integrated urban planning intended to achieve environmental enhancement and urban renewal in which multiple benefits of Blue-Green Cities are rigorously evaluated and understood. The Consortium's objectives are to: Put competent authorities, businesses and communities at the centre of the research by establishing feedback pathways between them and the FRM modellers, planners and decision makers to ensure co-production of knowledge; Model existing flood risks using coupled surface/sub-surface hydrodynamic models linked to semi-quantitative assessments of sediment/debris dynamics and habitats; Identify and assess candidate options for adaptive strategies combining hard and soft responses to flood risk that are capable of functioning as spatially-integrated, urban FRM systems; Use fieldwork to identify and understand the behavioural responses of individual and institutional stakeholders to the candidate options for FRM. Develop rules to represent these behaviours and employ agent-based modelling to simulate the responses to FRM options; Synthesise existing and novel performance measures to identify 'value added' at a range of scales and under flood/non-flood conditions, in an ensemble of contrasting, possible flood futures; Illustrate how this approach can be used to support learning from multiple feedback loops at every stage of FRM appraisal, decision making, implementation, evaluation and adaptation. In this paper we will present the initial outcomes of this project and discuss the future directions for the research.
Perfil Longitudinal Do Rio Tamanduateí E a Vegetação Ripária Remanescente: Análise Sob a Ótica Do Novo Código Florestal (PAP014557) - Abstract Only
Keywords: Rio Tamanduateí, Impactos Ambientais, Uso da terra, Novo Código Florestal, Vegetação Ripária
Subject: Land use and Floods, landslides and erosion
Abstract:
Diferentes sociedades humanas, ao longo de sua história, têm nos rios o registro de seu florescimento, e foram os grandes responsáveis pela sua fixação no lugar. Na antiguidade, os rios constituíram um meio de penetração do homem em direção ao interior dos continentes e, até hoje, muitos rios continuam exercendo esta função. A presente pesquisa analisou os usos e ocupação da terra sob a ótica do Novo Código Florestal ao longo da várzea do rio Tamanduateí, assim como a sua vegetação ripária remanescente. O rio Tamanduateí tem sua nascente na Serra do Mar, no município de Mauá e corta algumas cidades do ABC paulista, até desaguar na cidade de São Paulo, depois de percorrer 35km. O objetivo principal deste estudo foi identificar as diferentes formas de ocupação das margens do rio Tamanduateí e a sua relação com o Novo Código Florestal. Ainda, foram coletadas amostras de água na nascente, em diferentes pontos ao longo do canal e na foz, para assim identificar alguns parâmetros geoambientais do rio, como temperatura, condutividade e Ph.
Flood Disasters and Flood Warning in Urban Areas of Ukraine: Learned Lessons and New Challenges (PAP014640) - Abstract Only
Keywords: urban, flood, disasters, forecasting, warning
Subject: Flood forecasting and early warning systems
Abstract:
River floods and inundations connected with them are the most widespread and dangerous natural disasters in Ukrainian urban areas. A lot of cities, especially those located in the region of Carpathians mountains, are suffered from main four types of floods: regional floods (associated with large- or meso-scale weather patterns); spring-time floods (caused by the combination of melting snow and precipitation); ice floods (linked to ice phenomena on rivers); flash floods (caused by convective precipitation). The frequency and intensity of floods as well as the magnitude of damage caused have increased in many regions during the past decades. A large number of Ukrainian cities have been severely damaged from extreme floods which occurred in 1998, 2001, 2003, 2008, 2010 and 2012. Researches have shown the climate change and the irrational economic activities in the river basins are the major reasons of increasing the danger of flood hazards. Taking into account the fact that river floods affect large urban areas with intense economical development and high density of population the development of flood management is one of the most urgent task in the Ukrainian water-related policy. Among non-structural flood management measures a development of the Warning System is extremely important to be able to timely recognize dangerous situations in the flood-prone areas and to protect the societies against flood hazards. The flood disasters in different natural zones of Ukraine, present state, problems and new challenges in the development of different components of flood warning system in urban areas on national, local and international levels are considered in the paper. In particular, the following issues are considered: particularities of flood runoff formation in urban areas located in different natural zones, including, the impact of present and expected climate changes on the frequency and intensity of floods; assessment of socio-economic vulnerabilities (hazard to human life and health; a loss of city's lands; a shortage of water supply for different city's needs; a destruction of city's infrastructure) in major urban areas to flood hazards; institutional background of flood warning, including, the distribution of responsibility between central and local authorities in areas: monitoring and data collection; risk analysis, forecasting, warning decision and distribution, receipt and response; existing warning system, its main components and technical capabilities; flood monitoring and forecasting methods and technologies; international cooperation on transboundary rivers; major limitations and problems in the institutional, financial, technological and scientific support the flood warning system; new needs in the context of introducing the concept of the Integrated Flood Management and European principles of water-related legislation and standards; activities undertaken by central and local authorities, scientific community, non- governmental organizations to meet new challenges. The special attention is given to the development of the early flood warning system which is carry out by the State Emergencies Service in cooperation with the State Hydrometeorological Service. This development is based on integrating the hydrometeorological observation and forecasting with using the flood risk assessment approaches.
Aggregative Risk Evaluation in Regional Floodwater Utilization Based on Fuzzy Analytic Hierarchy Process (PAP014641) - Abstract Only
Keywords: region floodwater, floodwater utilization measures, aggregative risk rate, fuzzy analytic hierarchy process, model
Subject: Flood risk management in mega cities
Abstract:
According to the characteristics of regional floodwater utilization measures such as reservoirs, flood detention areas and canal storages etc. and risk generating mechanism of these floodwater utilization measures, the analysis method synthesizing grade of risk and grade of importance is used for computing flood risk from floodwater utilization sub-regions and various utilizing measures. Based on the relationship between the risk of regional floodwater utilization and risk from the floodwater utilizing measures of sub-regions, the mathematical model, which can consider the fuzzy property of flood risk assessment, is proposed for evaluating the aggregative risk of floodwater utilization by using Fuzzy Analytic Hierarchy Process (FAHP). The hierarchical structure and solving procedures of the model, synthesis analysis technique of grade of risk and grade of importance, as well as identifying method for the weights of fuzzy evaluating factors, are detailed. Finally, taking the Gaotang-Ahu Reservoir District in Xuzhou, Jiangsu Province as example, the aggregative risk rate is computed using the proposed model for evaluating risk in the regional floodwater utilization.
Assessing Direct and Indirect Economic Impacts of a Flood Event Through the Integration of Spatial and Computable General Equilibrium Modelling (PAP014687) - Abstract Only
Keywords: flood risk, indirect impacts, computable general equilibrium, economic losses
Subject: Floods in a changing climate
Abstract:
An integrated methodology for assessing direct and indirect economic impacts of flooding is developed and tested. The methodology combines a Geographic Information System spatial approach, with a general economic equilibrium approach using a downscaled modified version of a Computable General Equilibrium model at sub-national scale. The model is tested on a flood event that occurred along the Po river, in Northern Italy in October 2000. Given the level of uncertainty in the behavior of disaster-affected economies, a sensitivity analysis is performed including three disruption duration scenarios and two post-disaster recovery scenarios. Results confirm that indirect losses are significant, and the model is able to capture both positive and negative economic effects of a disaster in different areas of the same country.
Historical Assessment of Land Use Change Impact on the Urban Inundation Conditions (PAP014708) - Abstract Only
Keywords: histoircal assessment, land use change, urban inundation, flood
Subject: Urban Floods
Abstract:
In recent years, the urban flash floods are often occurred due to the extreme events. The flood inundation in urban area caused a lot of economic loss and death. Inundation simulation is very import for flood risk management to reduce the damage and economic loss and provide escape information of flood disaster. To analysis the long-term land use change in urban flood disaster, the paleo-inundation as a part of paleo-flood hydrology study is calculated under the historical events by using the historical information and modern methods. In this study, the main objectives are to reconstruct the paleo-inundation condition under the historical events and environment, link the grid-based rainfall-runoff model with the inundation model in the historical period, assess the effect of land use change on urban inundation, and give a discussion on the basic process of paleo-hydrology and paleo-inundation assessment. The results of the paleo-inundation plays an important role on reconstructing the flooding and damage conditions, evaluating the historical flood control policy, providing the experiences of historical flood risk management and escape technology.
Landslide Detection Using Polarimetric Sar Data and Genetic Programming (PAP014710) - Abstract Only
Keywords: landslides, genetic programming, sar, machine learning
Subject: Land use and Floods, landslides and erosion
Abstract:
We studied the utilization of polarimetric SAR information and machine learning algorithms to detect landslides. Decomposition methods of the scattering matrix were applied to L-Band SAR data from ALOS satellite and used as input for machine learning classification algorithm based on genetic programming. A case study of a landslide event triggered by rainfall in Brazil was conducted to evaluate and compare decomposition methods and its applicability for landslide detection. Obtained results were compared with manual classification using high-resolution satellite optical images.
Risk Assessment and Bidasoa Watershed Management Plan (PAP014712) - Abstract Only
Keywords: Flood Management Plan, Risk, Hazard
Subject: Urban Floods
Abstract:
The Bidasoa watershed has suffered many floods. The most destructive were: 1913, 1953, 1983, 2007 and we now have to add 2009 and 2011. Thus, it has been analyzed and evaluated on several occasions by various bodies, on different scale, scope and boundaries. This study seeks to analyze the flooding risks, and to establish measures to write the Management of Flooding Risks Plans (PGRI) of the 7 ARPSIs that the watershed encompasses, responding to the Royal Decree 903/2010 on watershed flooding risk assessment and management, transposing the Directive floods (2007/60/EC), while defining the legal zones of the Modification of the RDPH (RD 9/2008), i.e. DPH, Extreme Damage Zone, Intense Outflow Way and Preferred Flow Area, updating the Civil Protection Risk Areas, as well as the characteristic (defined by damages) flows, analyze the Risk Assessment by Zones according to the criteria set-out by the Navarra Government according to the flood characteristics for the Territorial Management Plans (POT), the analysis of other pending proposals as well as other structural and non-structural measures of local risk abatement such as enlargement of hydraulic capability. The study's scope are the main courses of the Bidasoa watershed on Navarra territory, totaling 104 km of river course, and 625 square km watershed. 1. Analysis of historical events and precedents All information in databases and GIS. 2. Geomorphological study, (orthophotos of 1929, 1956, 1984, 2010), 3. Pluviometric study: Regional analysis of the flood index on 60 pluviometers 4. Hydrological Study: Phoronomic study, total of 75 sub-watersheds, 5. Treatment of LIDAR cartography on flood zones. Course correction by batymetrics. 6. Hydraulic study: model used GUAD 2D. 7. Hazardousness analysis according to RD 903/2010 and characteristic flows. 8. Risk analysis according to POT criteria. 9. Management plan: Exposition of means: evacuation routes, SAT, etc... As a result maps, GIS, databases, documents, and others tools have been produced conducive to the goals. Main conclusions:  The influence of the hietogram, and the comparison between a unidimensional preliminary and a bidimensional study. Advantages and disadvantages.  Cartography's impact: advantages of LIDAR and the problems generated when it does not correspond to the hydraulic demands in breaklines and flood plains. This enquiry has produced essential information, and illuminated the need for calibration of the hydrological and hydraulic models.  The Bidasoa watershed is defined by steep slopes, where any significantly level terrain, sloped at less than 3%, lies in the lowest parts of the river valley, and is almost completely within the flood plain. Therefore population, infrastructure and services are concentrated in the alluvial.  The largest structural measures are already in place. The most efficacious to be considered will encompass the future planning of settlements, according to the criteria of the Navarra Government, the SAT SAD SAIH, and taking into account the concentration times of the river beds, and specific rain emergency thresholds, as well as the resiliency measures of buildings, conurbations and roads, and the surviving structures.
Frequency and Intensity of Extreme Rainfall Events From 1961 to 2010 in Distrito Federal, Brazil (PAP014715) - Abstract Only
Keywords: extreme rainfall, frequency, intensity, Distrito Federal, Brazil
Subject: Floods in a changing climate
Abstract:
Due to rapid and unplanned urbanization and changes in land use, the capital of Brazil is already experiencing a high risk to negative consequences caused by floods. The understanding of processes involved in risk reduction is essential to achieve the goals of reducing damages (i.e., life, food production, sanitation, transport, etc). The hazard is often inevitable and society is pushed to take actions on adaptation strategies to reduce vulnerability. However, reliable adaptation measures are based on information about the hazard, for instance the frequency and intensity of events. Potential changes in the variability of future regional precipitation may enhance impacts caused by floods; however, rainfall projections are still very uncertain. This in mainly due to the lack of capacity of global circulation models - GCMs in simulating the amount of rainfall influenced by convective systems. In order to provide valuable information about flood hazard in Distrito Federal, as well as interpret the results of GCMs, the assessment of rainfall extreme events is needed. Since rainfall is directly related to runoff, precipitation is one of the main drivers of flood hazard. For that, frequency and intensity of rainfall from 15 rain gauges are analysed. Rainfall extreme events can be measured by indices, such as the 95th percentile of the year, number of days for which precipitation rate exceeds 20, 40 and 60 mm; and maximum 5-day precipitation total. Results show that most of the rain gauges analysed present a fairly significant positive trend in the frequency and intensity of extreme rainfall. Independent on the causes of that, this information is valuable to support decision makers in taking action to minimize damages caused by flood events.
Principles of Sustainability for Stormwater Management (PAP014717) - Abstract Only
Keywords: Principles of Sustainability, Stormwater Management, Sustainable Urban Drainage
Subject: Land use and Floods, landslides and erosion
Abstract:
Sustainability is based on generic principles that can be used as guiding public policies, aimed at improving the planning and management as well as provides support to decision-making. Currently, the vast majority of urban drainage projects based on structural projects aimed at transferring through a process of fast flow rainwater downstream, transferring, at the same time, problems in time and space, fact that demonstrates unsustainable economically, socially and environmentally. This work was based on the general principles to develop thirteen specific sustainability principles in order to assist in the decision making and management of stormwater to reduce problems related to the topic and acting more sustainably.
Climate Change Impact on Flood Hazard and Adaptation Measures (PAP014722) - Abstract Only
Author(s): Mitja Brilly
Keywords: clima change, flood hazard, adaptation mesures, Sava River, Isonzo River
Subject: Floods in a changing climate
Abstract:
The flood risk determination we should put together flood hazard and vulnerability. Process develops analyzing exposure of human activity to flood hazard and consequences of it. For proper integration, we should develop a full picture of the flood hazard including climate change. The climate change impact on flood peaks estimate for the Sava River Basin and the Soča river basin, Climate change differ a lot even across relatively small river basin like The Soče River basin due to meteorological, geological and hydrological conditions. Downscaling, of maximum daily rainfall with 20 and 100 years return period from climate change models, was calculated by E-OBS data. Hydrological automatically calibrated model and simple correlation are used to calculate increase of flood discharges. Flood probability curves for periods of 30, 60 and 90 year ahead derived for different water stations. The frequency of flood discharges will increase significantly due the climate change. The impact differentiates according to hydrological and meteorological conditions. The increase is higher in mountainous regions and lower on alluvial plains and karst regions. Adaptation measures suggested according to future social development.
Impact of Climate Change on Large Catchment Hydrology of Yangtze River Basin (PAP014724) - Abstract Only
Keywords: Climate change, Extreme hydrologic event, Yangtze River Basin
Subject: Impact of climate change on flood risk
Abstract:
This paper presents estimates of water resources changes in Yangtze River Basin associated with climate change. The present climate (1970-1999) and future climate (2070-2099) at SRES A1B scenario are simulated by Regional Climate Model (RegCM4) at a spatial resolution of 50×50 km and used to force a large-scale hydrological model. The RegCM4 model shows good performance on not only the annual average but also the extreme events of temperature and precipitation. Most of the Yangtze River Basin in China stands out as "hotspots" of climate change, with an annual temperature increase of about 3° and an annual precipitation increase of 5-10% predicted, also with the strongest increase of daily rain intensity, maximum 5-day rain amount, and the number of consecutive dry days in China, suggesting increased risks of both floods and droughts. The climate scenario is based on model output from the European-Hamburg general climate model (ECHAM5). The Variable Infiltration Capacity model (VIC) is used to examine changes in stream flow at various locations throughout the Yangtze River Basin. Average stream flow, peak flows, low flows, and several water balance terms are evaluated for both the present and future period. The results reveal a distinct contrast between those periods. More floods and droughts are predicted at the end of 21st century.
Portuguese Flood Risk Assessment and Implementation of a Visualization Tool for Coordinated Actions and Collaborative Planning (PAP014727) - Abstract Only