Thesis (MA)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: This study was conducted in the Cuvelai Basin in Northern Namibia to assess vulnerability and socio-economic impacts of flooding on local residents, and to suggest ways to counteract the consequences of flooding in rural areas of the Basin. This followed severe flooding in 2009, 2011 and 2012. These combined flooding episodes had a substantial impact on local residents and the Namibian economy, with estimated losses of approximately US$136.4 million (NAD1364 million) in direct damage and US$78.2 million (NAD780 million) in indirect losses. The consequences of flooding amounted to ~1% of the country’s 2009 Gross Domestic Product (GDP). Rural residents in the Cuvelai Basin live predominantly on small farm holdings (‘ekove’) allocated by local village leadership, and depend heavily on subsistence farming for their livelihoods. Since higher-lying ground with soil best suited for crop production becomes scarcer, residents are allocated land in low-lying areas which are smaller and more susceptible to floods. The destruction of crops, farm and grazing land, trees and livestock, by floods and similar disasters is of a huge concern. The study sought to assess the impacts of flooding, geographical or physical circumstances that place residents at risk, and socio-economic conditions that lead to vulnerability. The study also attempted to assess whether traditional leaders (headmen) and village residents can use flood risk maps to create plans to reduce flood vulnerability. Over the past flood years, initiatives by the government to cope with floods have been response (relief), short-term and heavily donor dependent. To cope with floods and agro-climatic changes in their basin, rural residents have evolved their practices, some of which are traditional, to help lessen the impacts of floods on their livelihoods. Unfortunately such knowledge is not fully acknowledged by policy, decision makers and disaster risk managers. As a result of this knowledge gap, the study’s objective of compiling these practices, serves as a means to document localized traditional flood response, mitigation and adaptive measures. Moreover, the study will suggest contemporary adaptive measures as recommended by the local rural residents. Residents in 314 households were interviewed during August to November 2012. The households were selected following recommendations by village headmen, and consisted of 273 flooded homes, 42 village leaders, and 35 homes that were not flooded from 45 randomly selected villages. The qualitative data was captured, pre-coded, processed and analysed in Microsoft Excel, SPSS and STATISTICA to derive descriptive and inferential statistics. Following consultations with village headmen and residents, recommendations were made on practical adaptive strategies to flooding. The study found that there is a need to foster community level participation, buy-in and involvement in disaster risk management strategies in order to reduce the gap between technical early warning mechanisms and indigenous knowledge. Results revealed that households with coinciding socio-economic and geographic vulnerability are heavily impacted by flood disasters. However, these two vulnerabilities are not directly proportional to each other. Other vulnerable groups in society were outlined and structural and non-structural mitigation and preparedness measures at household level were recommended by the residents. It is the study’s intention that this will assist in strengthening local residents adaptive capabilities during events of flooding, thereby mitigating their impacts. The project’s intention of documenting this technical and indigenous knowledge, will serve as a knowledge base that can be compiled and integrated into an effective village friendly flood early warning system. It is further hoped that this initiative will garner support at the policy level and contribute to the prioritization of flood response to pending disasters being placed at the centre of development planning and execution. / AFRIKAANSE OPSOMMING: Hierdie studie is uitgevoer in die Cuvelai-opvangsgebied om die kwesbaarheid en sosio-ekonomiese impak van vloede op die plaaslike inwoners te bepaal ten einde maniere te vind om die gevolge van oorstromings in die landelike gebiede van die Cuvelai teen te werk. Ernstige oorstromings in 2009, 2011 en 2012 het 'n aansienlike impak op die Namibiese ekonomie gehad met geraamde verliese van ongeveer US$136.4 million (NAD1364 million) in direkte skade en US$78.2million (NAD780 million) in indirekte verliese vir die land. Ongeveer een persent (1%) van die land se 2009 bruto binnelandse produk (BBP) is benut om die gevolge van hierdie oorstromings aan te spreek. Landelike inwoners in die Cuvelai-opvangsgebied woon op kleinhoewes, plaaslik bekend as ekove, wat toegeken word deur plaaslike gemeenskapsleierskap. Hulle is hoofsaaklik afhanklik van bestaansboerdery. Aangesien hoër-liggende gebiede met goeie landboupotensiaal toenemend skaarser word, word nuwe kleinhoewes toegeken in laer-liggende gebiede, waar die negatiewe gevolge van oorstromings op inwoners erger kan wees. Skade aan gewasse, landbougrond en weiding, boorde en vee deur oorstromings en soortgelyke rampe is dus kommerwekkend. Die doelstelling van die studie was dus om die impak van oorstromings te bepaal, die geografiese of fisiese omstandighede wat plaaslike inwoners in gevaar stel te evalueer, en sosio–ekonomiese toestande wat lei tot kwesbaarheid te bepaal. Verdere doelwitte was om vas te stel of gemeenskapleiers en plaaslike inwoners vloedrisikokaarte kan gebruik om vloedkwesbaarheid te bepaal, in oorleg met plaaslike owerhede en inwoners alternatiewe praktiese aangepaste strategieë vir oorstromings vas te stel en aanbevelings aan die nasionale rampsbestuursbeleid en praktyk waar toepaslik te maak. Tydens die afgelope oorstromings was regeringsinisiatiewe om oorstromings te hanteer korttermyn vloedverligting, grootliks afhanlik van skenker. Om vloede en landbou-klimaatsveranderinge the hanteer, het landelike inwoners nuwe praktyke ontwikkel, sommige van tradisionele aard, om die impak van oorstomings op hulle lewensbestaan the verminder. Ongelukkig word sodanige kennis nie ten volle erken deur beleid, besluitnemers en ramprisikobestuurders nie. As gevolg van hierdie kennisgaping, dien die studiedoelwit om hierdie praktyke saam te stel die doel om gelokaliseerde tradisionele maatreëls aangaande vloedreaksie, versagting en aapasbaarheid te dokumenteer. Verder sal die studie onlangse maatreëls voorstel soos aanbeveel deur die plaaslike landelike inwoners. Ten einde kwalitatiewe data van die gemeenskappe wat in die Cuvelai woon te bekom is daar vir vier maande (Augustus tot November 2012) opnames gedoen by 314 huishoudings, gekies op aanbeveling van die plaaslike owerhede wat insluit 273 vloedslagoffers, 42 gemeenskapsleiers, en 35 huishoudings wat nie deur vloede beïnvloed is nie, vanuit 45 verskillende gemeenskappe. Die kwalitatiewe data is opgeneem, vooraf-gekodeer, verwerk en ontleed in Microsoft Excel, SPSS en STATISTICA om beskrywende en inferensiële statistieke te bekom. Die studie het bevind dat daar 'n behoefte is om die vlak van gemeenskapsdeelname te bevorder, inkoop en betrokkenheid by die ramp risikobestuurstrategieë te verkry ten einde die tegniese gaping tussen vroeë waarskuwingsmeganismes en inheemse kennis te verminder. Die studie het ook getoon dat huishoudings met ‘n gekombineerde sosio-ekonomiese en geografiese kwesbaarheid groter newe-effekte ondervind van vloedrampe. Die twee kwesbaarhede is egter nie direk eweredig aanmekaar nie. Ander kwesbare groepe in die samelewing is uitgewys, en strukturele en nie-strukturele versagting en paraatheidsmaatreëls op huishoudelike vlak is deur die inwoners aanbeveel. Die studie se doelwit is om die aanpasbaarheid van die plaaslike inwoners tydens oorstromings te bevorder, en sodoende die impak te verminder. Dokumentasie van hierdie tegniese en inheemse kennis sal dien as 'n kennisbasis wat saamgestel en geïntegreer kan word in 'n effektiewe gemeenskapsvriendelike vroeë vloedwaarskuwingstelsel. Indien hierdie inisiatief ondersteuning vind op beleidsvlak, kan dit bydra tot die prioritisering van vloed- en rampreaksie in ontwikkelingbeplanning en uitvoering.

The Diploma thesis on the theme "Assessment of flood control measures to protect the population in selected communities of the South Bohemia region in the catchment area of the river Lužnice" is divided into theoretical part and the research part. The theoretical part is a general whole, which in the sections refers to the relevant legislation of the flood problems, it explains the flood as the concept and everything associated with it. In particular it introduces the readers with flood characteristics of the territory of the Czech Republic and with the characteristics of the catchment area of the river Lužnice. It describes the selected municipalities by its flow, which are the subject of the research. It explains the difference between a natural and an extraordinary flood, describes the historic and contemporary floods and their damage. It deals with the protection from natural disasters, characterizes the activities of the relevant organs of the protection flood. In the context of the protection of the population it defines the summary measures that help to ensure the protection of life and health of the people, property and environment in emergencies, which are warning, evacuation, hide and emergency survival of the population and other measures to ensure the protection of life, health and property. The aim of this work is to evaluate the effectiveness of flood control measures from the perspective of the number of the protected inhabitants on the territory. In order to achieve the goals, it was necessary to make several consecutive steps. On the basis of assessed results it could be returned to the research question, whether the built flood protection measures are effective in relation to the protected values of the life, health, property and the environment. For the fulfillment of the objectives of the work and verification of research questions,it was need to be familiar with the relevant legislation of the subject, then with the implemented measures, flood protection plans of the municipalities including analysis of their substantive and organisational components. After that to perform the qualitative processing of the survey, the respondents of which were the statutory representatives of the municipalities, who are in charge of the flood protection, and other charged people (e.g. crisis management staff, officers of the Department of the environment or Building office, etc.). The found facts served to the description, evaluation, comparison and analysis of the flood control measures in relation to the number of the protected inhabitants within the catchment area of the river Lužnice. In this way the concrete results were obtained and discussed in the comments of this Diploma thesis. The submitted Diploma thesis in its research part assesses the effectiveness of the flood control measures in the framework of the protection of the population in the South Bohemia municipalities - Bechyně, Tábor, Planá nad Lužnicí, Soběslav, Dráchov, Veselí nad Lužnicí by the flow of river Lužnice, that touches the ranked in the river kilometres from 10,6 to 77,3 km lines. The inspiration for the processing of this Diploma thesis there were the consequences of disastrous floods in 2002, 2006 and 2013 in these areas, which have caused enormous damage and even loss of life. Then the personal interest of the author, as a resident of the town Veselí nad Lužnicí and respectively the member of the crisis management of this town. The research question and the methodology of the research were designed to be filled the objectives of this thesis, it means the evaluation of the effectiveness of the flood control measures from the perspective of the number of the protected inhabitants on the territory. The thesis evaluated the current status of flood protection, description, comparison and analysis were made. There were designed some of the other possible measures that would, in my opinion, led to the improvement of flood protection...

Since 1971, a number of flood frequency models have been developed for river basins in Malawi for use in the design of hydraulic structures, but the varied nature of their results have most often given a dilemma to the design engineer due to differences in magnitudes of calculated floods for given return periods. All the known methods for flood frequency analysis developed in country so far have not used a homogeneity test for the river basins from which the hydrological data has been obtained. This study was thus conducted with a view to resolving this problem and hence improve the design of hydraulic structures such as culverts, bridges, water intake points for irrigation schemes, and flood protection dykes. In light of the above, during the course of this study the applicability of existing methods in the design of hydraulic structures was assessed. Also, the study investigated how land use and land cover change influence the frequency and magnitude of floods in the study area, and how their deleterious impacts on the socio-economic and natural environment in the river basins could be mitigated / Environmental Sciences / M. Sc. (Environmental Management)

O crescimento populacional aliado à migração tem aumentado a pressão sobre o uso do solo urbano perpetuando sucessivos problemas de assentamentos informais e saneamento ambiental nos grandes centros. Esta situação se agrava ainda mais em épocas de chuvas intensas devido à ocorrência de enchentes. Este projeto faz parte de um conjunto de ações integradas de cidadania e inclusão social na região hidrográfica da baixada de Jacarepaguá, especificamente envolvendo a Comunidade da Vila Cascatinha, em Vargem Grande, a fim de gerar subsídios para políticas públicas em áreas de assentamentos informais, integrado ao projeto HIDROCIDADES (CNPq/CTHIDRO/CTAGRO), que visa a conservação da água em meios urbanos e periurbanos associado à cidadania, inclusão social e melhoria da qualidade de vida nas grandes cidades. Este projeto utilizou uma tecnologia adaptada dos telhados verdes para edificação popular (telhado de fibrocimento), com o objetivo de verificar aspectos construtivos, possíveis espécies com potencial de geração de renda, custos, efeitos no retardo do escoamento superficial das águas pluviais e outros benefícios associados a questões climáticas locais e de conforto do ambiente interno. Os resultados gerados demonstraram, entre outros, o estabelecimento de metodologia para implantação dos telhados verdes em habitações populares, o valor dos custos e resultados preliminares de espécies com potencial para geração de renda. Ainda, a implantação dos telhados verdes demonstrou ser promissora no controle do escoamento superficial, na aplicação do sistema de irrigação. Na simulação das chuvas, observou-se uma retenção de até 56% do volume precipitado. Observou-se o retardo da ocorrência do pico de até 8 minutos no telhado vegetado em relação ao telhado testemunho (convencional telhas fibrocimento). Foi observada a eficiência tanto no comportamento térmico interno como também no externo, uma redução da amplitude térmica interna em dia característico de verão (35,9 C), sendo capaz de r eduzir a temperatura interna em cerca de 2,0 C nos períodos mais quentes do dia e cerca de 4,0 C no ambiente externo em comparação com o telhado-testemunha (sem plantio), com potencial de modificação do microclima local. / The population growth and migration has increased the pressure on land use and urban occupation, increasing the problems of informal occupation (urban settlements) and environmental sanitation in large cities. This is even worse when urban floods occur. This project is part of a set of citizenship and social inclusion integrated actions in Jacarepaguá low-land hydrographic region, involving the Community of Vila Cascatinha, Vargem Grande, Rio de Janeiro, Brazil, in order to propose new public policies for informal settlements. This study is part of HIDROCIDADES project (CNPq / CTHIDRO / CTAGRO), which focus on water conservation in the urban and peri-urban environment associated to citizenship, social inclusion and life quality improvements in large cities. This project applied an adapted technology for green roofs on social interest buildings (fiber-cement tiles), in order to verify constructive aspects, possible crops to with income raising potential, costs, the effects on surface flow control and other benefits, such as buildings thermal comfort improving, microclimate. Results, demonstrated, among others, the establishment of a methodology for implementing green roofs for social interest buildings, costs and preliminary crops. In addition, the establishment of the green roof showed effects on controlling surface runoff. During the application of the irrigation system for rainfall simulation it was observed up to 56% retention of the total precipitation. It was observed a delay up to 8 minutes to runoff peak when comparing to the flow over tiles roof. It was verified the external thermal behavior, reducing the internal temperature range of typical days in summer (35.9 C), being able to reduce internal temperature by 2.0 C durin g warmer periods of the day and about 4.0 C in the external environment, compared with the tiles roof, being efficient on the local microclimate modification.

O crescimento populacional aliado à migração tem aumentado a pressão sobre o uso do solo urbano perpetuando sucessivos problemas de assentamentos informais e saneamento ambiental nos grandes centros. Esta situação se agrava ainda mais em épocas de chuvas intensas devido à ocorrência de enchentes. Este projeto faz parte de um conjunto de ações integradas de cidadania e inclusão social na região hidrográfica da baixada de Jacarepaguá, especificamente envolvendo a Comunidade da Vila Cascatinha, em Vargem Grande, a fim de gerar subsídios para políticas públicas em áreas de assentamentos informais, integrado ao projeto HIDROCIDADES (CNPq/CTHIDRO/CTAGRO), que visa a conservação da água em meios urbanos e periurbanos associado à cidadania, inclusão social e melhoria da qualidade de vida nas grandes cidades. Este projeto utilizou uma tecnologia adaptada dos telhados verdes para edificação popular (telhado de fibrocimento), com o objetivo de verificar aspectos construtivos, possíveis espécies com potencial de geração de renda, custos, efeitos no retardo do escoamento superficial das águas pluviais e outros benefícios associados a questões climáticas locais e de conforto do ambiente interno. Os resultados gerados demonstraram, entre outros, o estabelecimento de metodologia para implantação dos telhados verdes em habitações populares, o valor dos custos e resultados preliminares de espécies com potencial para geração de renda. Ainda, a implantação dos telhados verdes demonstrou ser promissora no controle do escoamento superficial, na aplicação do sistema de irrigação. Na simulação das chuvas, observou-se uma retenção de até 56% do volume precipitado. Observou-se o retardo da ocorrência do pico de até 8 minutos no telhado vegetado em relação ao telhado testemunho (convencional telhas fibrocimento). Foi observada a eficiência tanto no comportamento térmico interno como também no externo, uma redução da amplitude térmica interna em dia característico de verão (35,9 C), sendo capaz de r eduzir a temperatura interna em cerca de 2,0 C nos períodos mais quentes do dia e cerca de 4,0 C no ambiente externo em comparação com o telhado-testemunha (sem plantio), com potencial de modificação do microclima local. / The population growth and migration has increased the pressure on land use and urban occupation, increasing the problems of informal occupation (urban settlements) and environmental sanitation in large cities. This is even worse when urban floods occur. This project is part of a set of citizenship and social inclusion integrated actions in Jacarepaguá low-land hydrographic region, involving the Community of Vila Cascatinha, Vargem Grande, Rio de Janeiro, Brazil, in order to propose new public policies for informal settlements. This study is part of HIDROCIDADES project (CNPq / CTHIDRO / CTAGRO), which focus on water conservation in the urban and peri-urban environment associated to citizenship, social inclusion and life quality improvements in large cities. This project applied an adapted technology for green roofs on social interest buildings (fiber-cement tiles), in order to verify constructive aspects, possible crops to with income raising potential, costs, the effects on surface flow control and other benefits, such as buildings thermal comfort improving, microclimate. Results, demonstrated, among others, the establishment of a methodology for implementing green roofs for social interest buildings, costs and preliminary crops. In addition, the establishment of the green roof showed effects on controlling surface runoff. During the application of the irrigation system for rainfall simulation it was observed up to 56% retention of the total precipitation. It was observed a delay up to 8 minutes to runoff peak when comparing to the flow over tiles roof. It was verified the external thermal behavior, reducing the internal temperature range of typical days in summer (35.9 C), being able to reduce internal temperature by 2.0 C durin g warmer periods of the day and about 4.0 C in the external environment, compared with the tiles roof, being efficient on the local microclimate modification.

The recent high profile flooding events – that have occurred in many parts of the world – have drawn attention to the need for new and improved methods for water resources assessment, water management and the modelling of large-scale flooding events. In the case of the Zambezi Basin, a review of the 2000 and 2001 floods identified the need for tools to enable hydrologists to assess and predict daily stream flow and identify the areas that are likely to be affected by flooding. As a way to address the problem, a methodology was set up to derive catchment soil moisture statistics from Earth Observation (EO) data and to study the improvements brought about by an assimilation of this information into hydrological models for improving reservoir management in a data scarce environment. Rainfall data were obtained from the FEWSNet Web site and computed by the National Oceanic and Atmospheric Administration Climatic Prediction Center (NOAA/CPC). These datasets were processed and used to monitor rainfall variability and subsequently fed into a hydrological model to predict the daily flows for the Zambezi River Basin. The hydrological model used was the Geospatial Stream Flow Model (GeoSFM), developed by the United States Geological Survey (USGS). GeoSFM is a spatially semi-distributed physically-based hydrological model, parameterised using spatially distributed topographic data, soil characteristics and land cover data sets available globally from both Remote Sensing and in situ sources. The Satellite rainfall data were validated against data from twenty (20) rainfall gauges located on the Lower Zambezi. However, at several rain gauge stations (especially those with complex topography, which tended to experience high rainfall spatial variability), there was no direct correlation between the satellite estimates and the ground data as recorded in daily time steps. The model was calibrated for seven gauging stations. The calibrated model performed quite well at seven selected locations (R2=0.66 to 0.90, CE=0.51 to 0.88, RSR=0.35 to 0.69, PBIAS=−4.5 to 7.5). The observed data were obtained from the National Water Agencies of the riparian countries. After GeoSFM calibration, the model generated an integration of the flows into a reservoir and hydropower model to optimise the operation of Kariba and Cahora Bassa dams. The Kariba and Cahora Bassa dams were selected because this study considers these two dams as the major infrastructures for controlling and alleviating floods in the Zambezi River Basin. Other dams (such as the Kafue and Itezhi-Thezi) were recognised in terms of their importance but including them was beyond the scope of this study because of financial and time constraints. The licence of the reservoir model was limited to one year for the same reason. The reservoir model used was the MIKE BASIN, a professional engineering software package and quasi-steady-state mass balance modelling tool for integrated river basin and management, developed by the Denmark Hydraulic Institute (DHI) in 2003. The model was parameterised by the geometry of the reservoir basin (level, area, volume relationships) and by the discharge-level (Q-h) relationship of the dam spillways. The integrated modelling system simulated the daily flow variation for all Zambezi River sub-basins between 1998 and 2008 and validated between 2009 and 2011. The resulting streamflows have been expressed in terms of hydrograph comparisons between simulated and observed flow values at the four gauging stations located downstream of Cahora Bassa dam. The integrated model performed well, between observed and forecast streamflows, at four selected gauging stations (R2=0.53 to 0.90, CE=0.50 to 0.80, RSR=0.49 to 0.69, PBIAS=−2.10 to 4.8). From the results of integrated modelling, it was observed that both Kariba and Cahora Bassa are currently being operated based on the maximum rule curve and both remain focused on maximising hydropower production and ensuring dam safety rather than other potential influences by the Zambezi River (such as flood control downstream – where the communities are located – and environmental issues). In addition, the flood mapping analysis demonstrated that the Cahora Bassa dam plays an important part in flood mitigation downstream of the dams. In the absence of optimisation of flow releases from both the Kariba and Cahora Bassa dams, in additional to the contribution of any other tributaries located downstream of the dams, the impact of flooding can be severe. As such, this study has developed new approaches for flood monitoring downstream of the Zambezi Basin, through the application of an integrated modelling system. The modelling system consists of: predicting daily streamflow (using the calibrated GeoSFM), then feeding the predicted streamflow into MIKE BASIN (for checking the operating rules) and to optimise the releases. Therefore, before releases are made, the flood maps can be used as a decision-making tool to both assess the impact of each level of release downstream and to identify the communities likely to be affected by the flood – this ensures that the necessary warnings can be issued before flooding occurs. Finally an integrated flood management tool was proposed – to host the results produced by the integrated system – which would then be accessible for assessment by the different users. These results were expressed in terms of water level (m). Four discharge-level (Q-h) relationships were developed for converting the simulated flow into water level at four selected sites downstream of Cahora Bassa dam – namely: Cahora Bassa dam site, Tete (E-320), Caia (E-291) and Marromeu (E-285). However, the uncertainties in these predictions suggested that improved monitoring systems may be achieved if data access at appropriate scale and quality was improved.

Översvämningar till följd av skyfall har blivit allt vanligare och förväntas att öka i takt med klimatförändringarna. Översvämningar kan ställa till stora skador för ett samhälle, framförallt när de samhällsviktiga verksamheterna blir drabbade. För att undvika att detta sker bör samhället vara byggt för att tåla stora volymer vatten som faller vid ett skyfall. Ett steg för att nå dit är att göra en skyfallskartering där flödesvägar, vattenvolymer och översvämningens utbredning tas fram genom hydraulisk modellering. Utifrån skyfallskarteringen kan sårbara områden upptäckas och förebyggande åtgärder kan utföras för att minska översvämningens negativa påverkan. Akademiska sjukhuset i Uppsala är en samhällsviktig verksamhet och har tidigare haft problem med översvämningar. I den här studien har en skyfallskartering utförts på Akademiska sjukhusets område för att ta reda på översvämningens utbredning vid ett skyfall och vilka åtgärder som lämpar sig för att förhindra översvämningar. Skyfallskarteringen utfördes i det tvådimensionella (2D) hydrauliska modelleringsprogrammet MIKE 21 Flow Model. Eftersom en skyfallskartering baseras på många generaliseringar finns det vissa osäkerheter kring valet av parametrar. Därför har även en känslighetsanalys utförts kring valet av regntyp (Chicago Design Storm (CDS) jämfört med ett blockregn), regnets varaktighet, grönytornas avrinningskoefficient och markens infiltrationshastighet. Indata till modellen baserades på olika kartdata som bearbetades i GIS-programmet ArcMap. Flera olika regn med varierande återkomsttid simulerades. Resultaten visade att det blir översvämning inne på sjukhusområdet vid ett 100-årsregn som förvärras när återkomsttiden ökar. Åtgärdsanalysen utfördes genom att lägga in förändringar i höjdmodellen för att se hur det påverkar översvämningens utbredning. Analysen visade att åtgärder som jordvallar och höjdsättning av marken kan tillämpas på området för att minska översvämningsrisken. Resultatet från känslighetsanalysen visade att ett CDS-regn ger större översvämningskonsekvenser i modelleringen än om ett blockregn av samma återkomsttid och varaktighet används. Känslighetsanalysen av varaktigheterna visade att en lång varaktighet kan leda till låga flödestoppar som inte representerar ett skyfall väl. En avrinningskoefficient på 0,4 beskriver infiltrationen i området väl och när en större avrinningskoefficient används tenderar översvämningen att bli större på grönytorna. Till sist visade resultatet att infiltrationshastigheten är en känslig parameter som bör väljas efter mer noggrann analys av marken i modelleringsområdet. / Flooding as a cause of cloudbursts have become more common and is expected to increase with climate change. Floods can cause substantial damage to a society, especially when the critical societal functions are affected. To avoid this the city should be built to tolerate large volumes of water from cloudbursts. As a step on the way to accomplish this, a cloudburst mapping could be made where flow paths, water volumes and the extent of the flooding are studied through hydraulic modelling. Through the cloudburst mapping, vulnerable areas can be spotted, and flood prevention measures can be taken to lessen the extent of the floods negative impact. Uppsala University Hospital serves a critical societal function and has previously had problems with flooding. In this project a cloudburst mapping has been made in the two dimensinoal (2D) hydraulic modelling program, MIKE 21. This was done to find out the extent of a flood caused by a cloudburst event and what measures that can be taken to prevent floods. A cloudburst mapping is based off many generalized assumptions and there are some uncertainties when selecting the parameters. Because of this, a sensitivity analysis was performed on the selection of rain-type (Chicago Design Storm (CDS) vs. block-rain), rain duration, the runoff coefficient and the soil's infiltration capacity. The inputs of the model were based off different geographic data and then constructed in the GIS-program ArcMap. Several different rain events with varying duration and return periods were simulated. The results showed that there is considerable flooding in the area after a rain with a 100-year return period and it gets worse when the return period increases. The flood prevention analysis was made by editing the terrain to mimic flood prevention measures and study how the extent of the flood responds to the edits. The analysis showed that measures like soil barriers and changes in elevation were effective in lessening the risk of flooding. The results from the sensitivity analysis showed that a CDS-rain causes a more significant flooding compared to a block-rain of the same return period and duration. The sensitivity analysis of the rain duration proved that a long duration can lead to flat flow curves that doesn't resemble a flow curve from a cloudburst event. A runoff coefficient of 0.4 describes the infiltration in the area well and with a larger coefficient the flooding on greenery tend to grow. Lastly, the infiltration capacity proved to be a sensitive parameter that needs to be selected carefully, preferably after a thorough soil analysis.

The main aim of the thesis is an appraisal of the stream Oslava which belongs to the Náměšť nad Oslavou region with the focus on flood control of the town. The thesis asseses current state of the stream with respect to the state of riverbed, bulwark of the stream and evaluation of the capacity of the stream channel. Calculation water surface profiles have been made by usage of the 1D mathematical model HEC-RAS for selected N-year flows. The capacity of flows and objects in the given period has been detected. There is also a map of the water runoffs included and possible solutions of how to protect the area surrounding the stream are proposed. The thesis was complemented with hydroecological monitoring of the stream channel - the HEM analysis 2014.

MSc (Statistics) / Department of Statistics / Haulage trucks and cross border traders cross through Beitbridge border post from landlocked countries such as Zimbabwe and Zambia for the sake of trading. Because of global warming, South Africa has lately been experiencing extreme weather patterns in the form of very high temperatures and heavy rainfall. Evidently, in 2013 tra c could not cross the Limpopo River because water was owing above the bridge. For planning, its important to predict the likelihood of such events occurring in future. Extreme value models o er one way in which this can be achieved. This study identi es suitable distributions to model the annual maximum heights of Limpopo river at Beitbridge border post. Maximum likelihood method and the Bayesian approach are used for parameter estimation. The r -largest order statistics was also used in this dissertation. For goodness of t, the probability and quantile- quantile plots are used. Finally return levels are calculated from these distributions. The dissertation has revealed that the 100 year return level is 6.759 metres using the maximum likelihood and Bayesian approaches to estimate parameters. Empirical results show that the Fr echet class of distributions ts well the ood heights data at Beitbridge border post. The dissertation contributes positively by informing stakeholders about the socio- economic impacts that are brought by extreme flood heights for Limpopo river at Beitbridge border post

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