O desenvolvimento urbano altera significativamente o ciclo natural das bacias hidrográficas. Com o surgimento da drenagem urbana sustentável, o rápido escoamento das águas pluviais deu lugar à restituição das características naturais da bacia hidrográfica através do planejamento do desenvolvimento urbano aliado ao uso de técnicas compensatórias que promovem a infiltração e detenção de águas pluviais. Entretanto, em bacias urbanizadas, o uso das técnicas compensatórias tem alcance limitado, principalmente pelo alto grau de impermeabilização das bacias, pela falta de preocupação com a drenagem durante a expansão urbana, pela baixa disponibilidade de espaço e pelos altos custos de aplicação de medidas estruturais de drenagem urbana. Assim, os princípios de drenagem urbana sustentável são muitas vezes considerados inadequados a ambientes de urbanização consolidada. Desta forma, este trabalho teve por objetivo avaliar o desempenho do uso em conjunto de diversas técnicas compensatórias definidas através do desenvolvimento de mapas de adequabilidade de uma bacia hidrográfica urbana à aplicação das técnicas compensatórias e de simulação hidrológica. Foram avaliadas bacias de detenção, pavimentos permeáveis, jardins de chuva, telhados verdes, trincheiras de infiltração e microreservatórios individuais. O desempenho das técnicas compensatórias foi avaliado individualmente e trabalhando em conjunto. Mapas de adequabilidade foram criados para locação e quantificação das técnicas compensatórias na bacia hidrográfica. Os resultados mostraram que a aplicação extensiva de técnicas compensatórias em ambiente urbano pode provocar melhoras significativas na redução de vazão de pico e controle do volume de hidrogramas de cheia, com melhores desempenhos individuais de até 35,5% de redução de pico e 32,48% de redução de volume de hidrogramas (TR 2 anos) com o uso de trincheiras de infiltração e 12,77% de redução de vazão de pico e 9,57% de redução de volume (TR 100 anos) com o uso de telhados verdes. Simulando as técnicas compensatórias mais eficientes funcionando em conjunto, foram obtidas reduções de 59,00% de vazão de pico e 46,37% de redução de volume para precipitações de tempo de retorno de 2 anos e 25,66% de vazão de pico e 26,45% de redução de volume em precipitações de 100 anos de tempo de retorno. Assim, concluiu-se que a adaptação de regiões urbanizadas aos princípios da drenagem urbana sustentável é possível e eficiente, e bons resultados podem ser obtidos mesmo nos ambientes mais densamente ocupados. Entretanto, a falta de planejamento durante o desenvolvimento urbano e a pouca disponibilidade de espaço impede a otimização do arranjo espacial dos dispositivos e limita a eficiência de algumas técnicas compensatórias, principalmente aquelas de grande porte. / Urban development significantly alters the natural cycle of river basins. With the emergence of sustainable urban drainage, rapid stormwater runoff gave way to recovering the natural characteristics of the river basin through the urban development planning coupled with the use of compensatory techniques that promote the infiltration and detention of stormwater. However, in already urbanized basins, the use of compensatory techniques have limited reach, especially by the high impermeabilization of the basins, the lack of concern with drainage during urban sprawl, low space availability and high implementation costs of structural measures of urban drainage. Thus, the principles of sustainable urban drainage are often considered inadequate to consolidated urban environments. Therefore, this study aimed to evaluate the performance of the conjunction use of several compensatory techniques defined after developing suitability maps for the urban basin and hydrologic simulation. We evaluated detention basins, permeable pavements, rain gardens, green roofs, infiltration trenches and individuals cisterns. We assessed the performance of compensatory techniques working individually and working together. Suitability maps were created for positioning and quantification of compensatory techniques in the watershed. The results showed that extensive application of compensatory techniques in an urban environment could lead to significant improvements in peak flow reduction and control of hydrograms volume, with best individual performance up to 35.5% peak reduction and 32.48% hydrograms volume reduction (TR 2 years) using infiltration trenches and 12.77% peak flow reduction and 9 57% volume reduction (TR 100 years) using green roofs. Simulating the most efficient compensatory techniques working together, the results shown 59.00% of peak flow reductions and 46.37% of volume reduction to 2-years rainfalls and 25.66% peak flow reduction and 26.45% of volume reduction in 100-years rainfalls. Thus, we concluded that the adaptation of urbanized areas to sustainable urban drainage principles is possible and efficient, and good results can be obtained even in the more densely occupied environments. However, the lack of planning for urban development and the limited space availability prevents the optimization of devices spatial arrangement and limits the effectiveness of certain compensatory techniques, especially those large as detention basins.

Every year the Philippines get affected by a number of typhoons, which cause severe damage, sometimes due to flooding. The capital, Manila, is located on a flood plain that is partly at, and even below sea level and with several rivers crossing the area. These are some of the factors that contribute to that Manila often is affected by severe flooding. During ten weeks of the spring semester in 2014, this thesis was conducted as a completion of the bachelor program Geographic Information System (GIS) at Karlstad University, Sweden. Eight weeks were spent in Manila in the Philippines at the University of the Philippines Diliman, School of Urban and Regional Planning (UP SURP). The aim of the study was to investigate how hospitals in Manila City get affected during flooding. GIS was used to perform network analyses, in order to calculate the shortest route for the emergency service to travel from a station via a barangay to a hospital. The shortest alternative route during a 5-year flood was also calculated in order to compare the distance differences that might be due to flood. During a 100-year flood another type of analysis was performed, where suggestions for suitable locations for placing emergency service and temporary medical centre were presented. These suggestions on suitable locations were placed in an area that will not be affected during a 100-year flood. Results from the analyses showed that Manila City is a very exposed area during flood. During a 5-year flood some parts of Manila City will be highly exposed and about 1/4 of the population will be affected. The shortest alternative route for the emergency service to use during flood will generally be longer than in normal situations. Some hospitals cannot be accessed from some barangays due to impassable roads. During a 100-year flood the area gets gravely affected, almost 2/3 of the population will be affected and many roads become impassable, which limits the accessibility in Manila City.

Flooding has become a problem of national proportion and many scholars have started to take note of the human impacts in this area. This study will focus on the social vulnerability framework in tandem with the environmental justice theoretical frameworks being applied to Polk County Iowa so that information can be added to the body of works within a Midwestern U.S. context. This research will contribute to the current geographical knowledge in natural hazards, environmental justice, and vulnerability to flood hazards. Taking into consideration the scarcity of county or sub-county studies in the Midwest U.S. measuring spatial tendencies in hazards vulnerability, this thesis is fitting. This study examines Polk County Iowa for social vulnerability factors present today to the natural disaster of flooding and then looks longitudinally back to 1990 to see if similar individual variables were also prominent historically. This study utilizes block group census level data and creates from it a social vulnerability index (SoVI) following Cutter et al. (2003). The study then used FEMA flood risk level boundaries and the 100-year floodplain to create a comparison of vulnerability of higher flood risk areas and lower risk areas to see if exposure to flood prone areas coincides with an increase or decrease in social vulnerability. Findings of statistical tests and the bivariate choropleth map of the study area suggest that Polk County exhibits a spatial vulnerability paradox, where the persons most socially vulnerable do not necessarily always preside in the source area for flooding. Interestingly enough the study suggests that risk capable and risk resilient populations live in some of the most physically risky places. An examination of specific individual vulnerability factors from the present and historically in 1990 give the same picture of spatial paradoxical vulnerability, leading many variables to be inconclusive. However, four variables (QFAM, QMOBILE, QEXTRACT, and AVGTRVL) did show correlation to prolonged historical disenfranchisement within the flood boundaries. It is crucial to take this information and widen the spatial location of risk from the present immobile boundary set forth and perpetuated by government entities, to a realistic flexible range of spatial locations that consider historical cultural forces and formulate new mitigation policies from these understandings. This thesis further highlights the need to use multiple interdisciplinary methods to understand what is happening within our space, place, and time. This thesis adds to the ever-growing literature in social vulnerability, and environmental justice but in a U.S. Midwestern context instead of a U.S. coastal context to a flood hazard situation.

O problema das inundações em Eldorado foi abordado integrando disciplinas e assuntos das áreas de Geociências, de Urbanismo, e de Arquitetura e de Defesa Civil, incluindo também a interação com diversas instituições e grupos acadêmicos, com o propósito de verificar os presentes esforços institucionais e comunitários na abordagem da crescente questão dos desastres. O estudo, aproveitando metodologias de cartografia e SIG, procurou contribuir com o desenvolvimento de meios para concretizar medidas de prevenção, mitigação, resposta e recuperação nas áreas mais sujeitas aos desastres relacionados aos processos hidrológicos ou geológicos na bacia hidrográfica em estudo. A urbanização no Vale do Ribeira de Iguape ocorreu historicamente em estreita relação com as condições que a hidrografia permitiu inicialmente ao transporte fluvial de pessoas e materiais. Este fato condicionou em grande medida a localização dos principais assentamentos e é possível vinculá-lo a períodos pré-cabralinos, quando outros grupos culturais já teriam iniciado a ocupação que hoje vemos sob o espectro de um processo de industrialização, implicando em uma intensificação da ocupação e do uso dos recursos do meio ambiente. No caso de Eldorado-SP, se a proximidade dos corpos d\'água trazia benefícios ao desenvolvimento e manutenção dos núcleos assentados, a expansão e adensamento da ocupação, sem a devida integração urbanística às condições do meio ambiente, tem incrementado as vulnerabilidades da cidade. Nas cheias do Rio Ribeira de Iguape e seus afluentes, muitas famílias estão sujeitas a riscos à vida, às condições de saúde e de perdas de recursos materiais e econômicos. / Floods in Eldorado (SP) was approached integrating disciplines and subjects of the Geosciences, Urban Planning, Architecture and Civil Defence, also including the interaction with various institutions and academic groups, in order to verify the present institutional and community efforts in facing growing issue of disasters. The study, taking advantage of cartography and GIS methodologies, sought to contribute to the development of means to implement prevention, mitigation, response and recovery in susceptible areas to disaster related to geological or hydrological. Urbanization in the Ribeira do Iguape Valley occurred historically in close relationship with the hydrographic conditions that initially allowed the fluvial transport of people and materials. This fact, conditioned the location of the major settlements and we can relate it to pré-cabralinosperiods when other cultural groups have already begun the occupation that we see today under of an industrialization process, resulting in increased occupancy, whitout urban integration to environmental conditions, has increased the vulnerability of the city. In the floods of Ribeira and its tributaries, many families are subject to risks to life, health conditions, material losses and economic resources losses.

In 2008 flooding occurred over a majority of Iowa, damaging homes, displacing residents, and taking lives. In the wake of this event, the Iowa Flood Center (IFC) was charged with the investigation of distributed flood mitigation strategies to reduce the frequency and magnitude of peak flows in Iowa. This dissertation is part of the several studies developed by the IFC and focused on the application of a coupled physics based modeling platform, to quantify the coupled benefits of distributed flood mitigation strategies on the reduction of peak flows in an agricultural watershed. Additional investigation into tile drainage and terraces, illustrated the hydrologic impact of each commonly applied agricultural practice. The effect of each practice was represented in numerical simulations through a parameter adjustment. Systems were analyzed at the field scale, to estimate representative parameters, and applied at the watershed scale. The impact of distributed flood mitigation wetlands reduced peak flows by 4 % to 17 % at the outlet of a 45 km2 watershed. Variability in reduction was a product of antecedent soil moisture, 24-hour design storm total depth, and initial structural storage capacity. The highest peak flow reductions occurred in scenarios with dry soil, empty project storage, and low rainfall depths. Peak flow reductions were estimated to dissipate beyond a total drainage area of 200 km2, approximately 2 km downstream of the small watershed outlet. A numerical tracer analysis identified the contribution of tile drainage to stream flow (QT/Q) which varied between 6 % and 71 % through an annual cycle. QT/Q responded directly to meteorological forcing. Precipitation driven events produced a strong positive logarithmic correlation between QT/Q and drainage area. The addition of precipitation into the system saturated near surface soils, increased lateral soil water movement, and reduced the contribution of instream tile flow. A negative logarithmic trend in QT/Q to drainage area persisted in non-event durations. Simulated gradient terraces reduced and delayed peak flows in subcatchments of less than 3 km2 of drainage area. The hydrographs were shifted responding to rainfall later than non-terraced scenarios, while retaining the total volumetric outflow over longer time periods. The effects of dense terrace systems quickly dissipated, and found to be inconsequential at a drainage area of 45 km2. Beyond the analysis of individual agricultural features, this work assembled a framework to analyze the feature at the field scale for implementation at the watershed scale. It showed large scale simulations reproduce field scale results well. The product of this work was, a systematic hydrologic characterization of distributed flood mitigation structures, pattern tile drainage, and terrace systems facilitating the simulation of each practices in a physically-based coupled surface-subsurface model.

The planet is currently experiencing a massive shift in the migration of people towards highly populous metropolitan regions which offer a better quality of life, which has resulted in rapid development and expansion. Meanwhile, the recent studies on climate change have shed light on precipitation events becoming increasingly wetter and intense. This rapid change in the land use patterns coupled with the climate change has increased the risk of flooding and puts the massive investment in the infrastructure, economy, and human life at a greater risk than ever before. This study aims to analyze the impacts of the stormwater infrastructure on the hydrology and hydraulics of highly urbanized environments. Traditional flood modeling approaches of independent hydrologic and hydraulic models have progressed into more complex models which can integrate the surface and sub-surface along with their interactions as the understanding of these physical processes and the availability of computational power has increased. A fully integrated hydro-systems model based on a distributed modeling approach is developed for a portion of the City of Minneapolis in Minnesota, USA which incorporates the surface hydraulics, stormwater infrastructure, vadose zone and a dynamic water table which realistically represents all the hydrologic and hydraulics processes. The result of this study shows the incorporation of the stormwater infrastructure in the integrated model leads to lower flood inundation areas, reduced vadose zone storage and lowered groundwater table for design flows as well as real events. The model displayed consistent results for the impact of stormwater infrastructure when tested across varied antecedent soil conditions. Ultimately this study proposes the implementation of a fully integrated hydro-systems modeling approach which link the hydrology and the hydraulics of the surface, sub-surface and stormwater infrastructure systems for a better representation of the flood hydrodynamics in urbanized regions.

>Magister Scientiae - MSc / Somerset West and Strand in the Western Cape, South Africa, were developed on the Lourens River floodplain. This hardened the catchment and reduced the capacity of the river to transport and store floodwaters. The result was recurrent flooding of residential and industrial areas and a fear that this could lead to loss of human life. In response to these concerns, the City of Cape Town implemented flood alleviation measures with a ‘soft’ engineering approach that incorporated geomorphological and ecological principles into their design. This was one of the first engineer/ecologist collaborations in South Africa, which attempted to make better decisions for the river ecosystem within the constraints imposed on it by urban development; and in so doing to create a self-sustaining river that requires little ongoing manipulation. The aim of this dissertation was to assess the extent to which ecological considerations were incorporated into the flood alleviation works on the Lourens River and whether this improved physical habitat and the diversity of riverine biota. Physical habitat was mapped from 1:50 000 topographic maps and aerial imagery in a GIS, and cross-sectional profiles, diversity of hydraulic biotopes and subtsrate composition were surveyed in the field.

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Flood severity and frequency have grown over the years as a result of urban development and climate change. Floods in cities cause major challenges such as property and infrastructure damage, transportation congestion, loss of life, environmental threats, and health concerns. To relieve the load on the urban drainage system and prevent flooding, effective measures to strengthen its resilience are required. Traditional design methods, which rely on past performance trends and long lifespans, usually result in infrastructure that is inflexible and unable to adapt to changing situations. Those traditional studies focused on drainage design, such as pipe slope and diameter optimization, coupling design cost limitation. Furthermore, various terminologies for the overall concept of green/grey infrastructure have been proposed in the literature. Some studies have been focused on the optimization of the suitable locations for storage tanks, which would be one of the most efficient approaches. Building storage facilities such as retention or detention basins are a cost-effective and efficient structural option to improve the resilience of urban sewerage system, reducing peak runoff in existing drainage systems in urban areas, especially compared to traditional methodologies such as increasing pipe diameter or slope providing sufficient hydraulic capacity. The basic concept is to create an optimization framework using Non-dominated Sorting Genetic Algorithm II (NSGA II), coupling with hydraulic model SWMM, and use it to change a number of drainage system-related variables such pipe diameter, slope, and storage unit size. The main idea of the optimization framework in thesis is to combine different methods into one framework, which is a challenge in a complex system due to the dilemma between the resilience objective and financial limitation. Literature review would shows that the recent research in terms of sewerage system resilience optimization utilizing different methodologies. Application of the system would shows that optimization model has the capability to improve the resiliency of urban sewerage system. The main objective of the thesis are (i) develop a new framework to optimize volume and location of storage units in urban drainage systems; (ii) develop a two-stage multi-objective optimization framework; (iii) develop the new index to make the optimization process feasible.