The aim of this thesis is to map an anti-flooding protection in locality Dobrá Voda near Hořice and to create suitable plan of a water retention reservoir. Retention reservoir works as a system for holding and transformation of flood wave and thus for dealing with floods. First part of this thesis covers general description of issues of floods, current legislature, anti-flooding measures and a description of flood wave transformation. Methods for determination of retention seepage of the reservoir are described in this part as well. Computer programmes (HEC-RAS, Transformwave) were used for the purpose of above mentioned determination. In the second part of this thesis the given locality is described including all the possible risks and plans of convenient anti-flooding measures. The results of appropriate software determinations are compared in this part of the thesis as well. A final plan of a suitable retention reservoir is based on the results of comparison.

Climate change results to more extreme and frequent flood events that induce extra risk to flood protection structures such as levees. Thus, estimation of the probability of levee failure is of utmost importance when it comes to structural safety and flood risk assessment. This master thesis focuses on the estimation of the probability of levee failure owing to backward erosion at the foundation of the levee. For the estimation of the probability of failure three breach models of different complexity were developed and site-specified data were used from the Paglia river area and an assessment of the results followed. Besides the breach models, a 2-D hydraulic model was also built where breach scenarios were used to assess the associated flood risk. The results showed that the complexity of the breach model plays significant role to the estimated probability of failure. The simplest model estimated the lowest probability, while the complex the highest. Consequently, the associated to the complex model flood risk was higher than the other two. / Klimatförändringarna är ett allmänt problem som bland annat resulterar i ökad risk för extrema hydrologiska händelser. Av dessa extrema händelser är översvämningar bland de mest förekommande. För att tackla problemen med översvämningsriskerna används skyddsvallar som en av de vanligaste anläggningarna bland olika översvämningsskydd. Vid ett tillräckligt högt flöde kan dock den ökade belastningen på skyddsvallen orsaka att skyddsvallen havererar. En skyddsvall kan haverera på grund av flera fysikaliska fenomen, varav de vanligaste är inre erosion, otillräcklig släntstabilitet samt överspolning. Risken för att en skyddsvall havererar, det vill säga brottrisken, kan beräknas med olika metoder. Sannolikhetsbaserade metoder har nyligen växt fram som ett allt viktigare tillvägagångssätt. Det här examensarbetet handlar om brottsannolikhetsberäkningar för skyddsvallar i syfte att kartlägga översvämningsrisker. Arbetet fokuserar på fenomenet med inre erosion i skyddsvallars grundläggning. Det praktiska exemplet i examensarbetet studerar nybyggda skyddsvallar utmed den italienska floden Paglia längs en flodsträcka om 4,5 km mellan städerna Ciconia och Orvieto Scalo i regionen Umbria i centrala Italien. Ur ett hydrogeologiskt perspektiv karaktäriseras regionen av fint jordmaterial, med inslag av slutna akviferer. Sannolikhetsberäkningar med hjälp av ramverket för Monte Carlo-analys genomfördes för tre olika modeller för att beskriva inre erosion i skyddsvallarna till följd av ett 200-årsflöde. De tre olika numeriska modellerna kännetecknades av olika grad av komplexitet. Den enklaste modellen baserades på en metod av Mazzoleni et al. (2015) och tog endast hänsyn till skyddsvallens porositet. Den mellankomplexa modellen var baserad på metoden ifrån Khilar et al. (1985). Den mest komplexa modellen var tidsberoende och baserades på metoderna från Sellmeijer et al. (2011) och Scheuermann (2005), för att ta hänsyn till de två ömsesidigt beroende fenomenen bakåterosion, så kallad ”piping” och läckage, så kallat ”seepage”, vilka tillsammans ger upphov till inre erosion. Resultaten visar att graden av komplexitet i den numeriska modellen spelar en viktig roll när det gäller brottsannolikheten för skyddsvallars grundläggning. Den enklaste modellen beräknade en lägre brottsannolikhet än de andra två modellerna, och den mest komplexa modellen beräknade högst brottsannolikhet av de tre modellerna. Vidare visar resultaten på att några parametrar har en stor inverkan på brottsannolikheten. Dessa är bland annat partikeldiametern som påverkar skjuvhållfastheten i materialet, permeabiliteten, jordlagrets tjocklek under skyddsvallen samt strömningsvaraktigheten. Parametern strömningsvaraktighet kan endast beaktas i tidsberoende modeller, vilket är en av fördelarna med den mest komplexa modellen i denna studie. Förutom de numeriska brottsannolikhetsmodellerna byggdes en tvådimensionell hydraulisk modell upp för att kartlägga de resulterande översvämningsriskerna. Tre olika haveriscenarier studerades för att representera de tre brottsannolikhetsmodellerna. Dock visade det sig att den enklaste av de tre modellerna beräknade så låg brottsannolikhet att det inte var meningsfullt att studera de resulterande översvämningsriskerna enligt den enklaste brottsannolikhetsmodellen i den hydrauliska modellen. Av de två mer komplexa brottsannolikhetsmodellerna visade det sig att den mest komplexa av de två gav mer omfattande haverier i skyddsvallarna och dessutom haverier i flera av skyddsvallarna. Vidare gav den mest komplexa modellen upphov till högst vattennivåer bakom de havererade skyddsvallarna. Slutligen kan det nämnas att staden Scalo Orvieto är utsatt för en högre översvämningsrisk än staden Ciconia enligt resultaten i denna studie.

This study addresses flood risk assessment in the Catalpa Creek watershed, located in northeast Mississippi, USA. Employing the Hydrological Modeling System (HEC-HMS) and the River Analysis System (HEC-RAS), integrated models were developed and calibrated, to predict flood behavior within the watershed. The study conducted flood frequency analyses for return periods ranging from 2 to 100 years and generated flood inundation maps, pinpointing flood-prone areas. Mitigation measures for flood risk management were recommended. The results underscore the effectiveness of the integrated modeling approach for simulating and understanding the complex dynamics of flood events. The research identified critical flood-prone zones, emphasizing the importance of proactive flood risk management. The calibrated hydrological model serves as a valuable tool for stormwater management, water resource planning, and watershed assessment. The study provides insights into flood risk in the Catalpa Creek watershed, offering valuable guidance to regional decision-makers. This study lays the foundation for future investigations in floodplain encroachment, sediment transport, stream restoration, and flood inundation hazard mapping.

No description available.

No description available.

A presente pesquisa concentra-se no estudo hidrológico utilizando o potencial das geotecnologias na modelagem do escoamento na bacia do rio Bengalas, cujo rio principal de mesmo nome, corta o município de Nova Friburgo, RJ, no sentido Sul-Norte. Esse município, um dos mais importantes da região serrana, sofre frequentemente com inundações e deslizamentos, onde, dados históricos e acontecimentos recentes mostram que a ocupação inadequada de encostas e calhas dos rios são as áreas destacada e negativamente afetadas. A metodologia tem suporte no uso de um SIG, extraindo informações, que por sua vez, serão entrada de dados na fase de modelagem, e reforçando a apresentação dos resultados das simulações através de mapas. Ela está divida basicamente em três etapas: "SIG", "Modelagem" e "Suporte à Tomada de Decisão/Simulação". Esse primeiro estudo permitiu compor um banco de dados geográfico com as características fisiográficas da bacia; a seleção criteriosa de uma modelagem matemática e encadeamento de seus parâmetros com os componentes do ciclo hidrológico; realizar a calibração do modelo de transformação chuva-vazão, Soil Conservation Service (CN); e simular a passagem dos volumes gerados pela precipitação efetiva na calha do rio Bengalas, com o objetivo de identificar e analisar as áreas suscetíveis a inundações na porção central da cidade de Nova Friburgo. Modelagem dessa natureza vem sendo empregada, principalmente, no gerenciamento de recursos hídricos, onde a tomada de decisões embasada nos resultados de simulações computacionais, contribuem para evitar prejuízos materiais e financeiros, e ainda, perdas de vidas humanas em áreas de risco, neste caso, aquelas suscetíveis a inundações. Analisando os resultados encontrados temos que a área suscetível à inundação para uma chuva com tempo de recorrência de 50 anos, o mais crítico estudado, seja de aproximadamente 1,0 km, distribuídos nos seus 8,5km na região central de Nova Friburgo-RJ, sendo está, ora delimitada, prioritariamente edificada. / This research focuses on the hydrological study using the potential of geotechnology into runoff modeling of the Bengalas Basin, whose main river, with same name, crosses the city of Nova Friburgo - RJ, in a south-north orientation. This city, one of the most important in "Região Serrana", suffers often with floods and landslides, which, historical data and recent events show that the inappropriate occupation of hillsides and margins of rivers are the highlighted and negatively affected areas. The methodology has basis in a GIS application, extracting information, which in turn, are input in the modeling phase, and enhancing the presentation of simulation results through maps. It is basically divided into three stages: "SIG", "Modelagem" and "Suporte à Tomada de Decisão/Simulação." This first study allowed to compose a geographic database with the physiographic features of the basin; the careful selection of a chain of mathematical modeling and its parameters with the hydrological cycle components, perform the calibration of the rainfall-runoff transformation model, Soil Conservation Service (CN) and simulate the transition of volumes generated by an effective precipitation in the Bengalas river, in order to identify and analyze the susceptible flooding areas in the central part of Nova Friburgo. A kind of this modeling has been used, mainly, in the water resource management, in which decision-making are based on results of computer simulations, helps to avoid a range of losses, such as material, financial and, especially, humans, that in this case, people who lives in areas susceptible to flooding. Analyzing the results, it was found that an area susceptible to flooding by a rainfall with a recurrence time of 50 years, the most critical studied, results in approximately 1.0 km, distributed in its 8.5km (central part of Nova Friburgo - RJ) which this bounded area has a great part with buildings.

A presente pesquisa concentra-se no estudo hidrológico utilizando o potencial das geotecnologias na modelagem do escoamento na bacia do rio Bengalas, cujo rio principal de mesmo nome, corta o município de Nova Friburgo, RJ, no sentido Sul-Norte. Esse município, um dos mais importantes da região serrana, sofre frequentemente com inundações e deslizamentos, onde, dados históricos e acontecimentos recentes mostram que a ocupação inadequada de encostas e calhas dos rios são as áreas destacada e negativamente afetadas. A metodologia tem suporte no uso de um SIG, extraindo informações, que por sua vez, serão entrada de dados na fase de modelagem, e reforçando a apresentação dos resultados das simulações através de mapas. Ela está divida basicamente em três etapas: "SIG", "Modelagem" e "Suporte à Tomada de Decisão/Simulação". Esse primeiro estudo permitiu compor um banco de dados geográfico com as características fisiográficas da bacia; a seleção criteriosa de uma modelagem matemática e encadeamento de seus parâmetros com os componentes do ciclo hidrológico; realizar a calibração do modelo de transformação chuva-vazão, Soil Conservation Service (CN); e simular a passagem dos volumes gerados pela precipitação efetiva na calha do rio Bengalas, com o objetivo de identificar e analisar as áreas suscetíveis a inundações na porção central da cidade de Nova Friburgo. Modelagem dessa natureza vem sendo empregada, principalmente, no gerenciamento de recursos hídricos, onde a tomada de decisões embasada nos resultados de simulações computacionais, contribuem para evitar prejuízos materiais e financeiros, e ainda, perdas de vidas humanas em áreas de risco, neste caso, aquelas suscetíveis a inundações. Analisando os resultados encontrados temos que a área suscetível à inundação para uma chuva com tempo de recorrência de 50 anos, o mais crítico estudado, seja de aproximadamente 1,0 km, distribuídos nos seus 8,5km na região central de Nova Friburgo-RJ, sendo está, ora delimitada, prioritariamente edificada. / This research focuses on the hydrological study using the potential of geotechnology into runoff modeling of the Bengalas Basin, whose main river, with same name, crosses the city of Nova Friburgo - RJ, in a south-north orientation. This city, one of the most important in "Região Serrana", suffers often with floods and landslides, which, historical data and recent events show that the inappropriate occupation of hillsides and margins of rivers are the highlighted and negatively affected areas. The methodology has basis in a GIS application, extracting information, which in turn, are input in the modeling phase, and enhancing the presentation of simulation results through maps. It is basically divided into three stages: "SIG", "Modelagem" and "Suporte à Tomada de Decisão/Simulação." This first study allowed to compose a geographic database with the physiographic features of the basin; the careful selection of a chain of mathematical modeling and its parameters with the hydrological cycle components, perform the calibration of the rainfall-runoff transformation model, Soil Conservation Service (CN) and simulate the transition of volumes generated by an effective precipitation in the Bengalas river, in order to identify and analyze the susceptible flooding areas in the central part of Nova Friburgo. A kind of this modeling has been used, mainly, in the water resource management, in which decision-making are based on results of computer simulations, helps to avoid a range of losses, such as material, financial and, especially, humans, that in this case, people who lives in areas susceptible to flooding. Analyzing the results, it was found that an area susceptible to flooding by a rainfall with a recurrence time of 50 years, the most critical studied, results in approximately 1.0 km, distributed in its 8.5km (central part of Nova Friburgo - RJ) which this bounded area has a great part with buildings.

Negative effects on water quality are created by eutrophication of the world’s water resources. Mitigation measures have been implemented, but poor improvements in water quality have been observed. Two-stage ditches have the possibility to increase nutrient and sediment retention to reduce eutrophication in receiving water bodies. A two-stage ditch has floodplain terraces on each side of the ordinary main channel. The terraces are available for flooding during high water flows and enables decreases in flow velocities. However, more knowledge is needed about the two-stage ditch and its effect in Swedish landscapes. The aim of the project was to study the two-stage ditch design with focus on water retention. Optimization of the two-stage ditch design was made by modeling and simulating design parameters and vegetation in the software Hydrologic Engineering Center’s River Analysis System (HEC-RAS). An existing two-stage ditch in Sweden was used as base and comparison to the theoretical model. In addition, a climate change scenario was studied to evaluate the impact of increased storm events in a two-stage ditch. Results showed that increased retention time of water, nutrients, and sediments theoretically can be given by designing two-stage ditches with maximum terrace width and minimum terrace height, and with terraces angled away from the main channel. Vegetation should also be kept on both terraces and in the main channel of the two-stage ditch to increase retention time. The study also showed that the two-stage ditch design has the possibility to decrease peak water levels during storm events, which can be expected to increase in the future. The impact on transport of nutrients and sediments from more future extreme hydrological events needs further studies. / Negativa effekter i vattenkvalitet skapas av övergödning i världens vattenresurser. Åtgärder för att begränsa övergödningen har genomförts, men svaga förbättringar i vattenkvalitet har noterats. Tvåstegsdiken har möjligheten att öka retentionen av näringsämnen och sediment för att minska övergödning. Ett tvåstegsdike har terrasser på vardera sida om den vanliga mittfåran. Terrasserna är tillgängliga för översvämning vid höga vattenflöden, vilket möjliggör minskning av flödeshastigheter. Dock krävs mer kunskap för tvåstegsdiken och dess effekt i svenska landskap. Syftet med projektet var att studera designen av tvåstegsdiken med fokus på retention av vattenflöde. Optimering av tvåstegsdikens design genomfördes via modellering och simulering av designparametrar och vegetation i programvaran Hydrologic Engineering Center’s River Analysis System (HEC-RAS). Ett befintligt tvåstegsdike i Sverige användes som bas och jämförelse mot den teoretiska modellen. Ett scenario för klimatförändring studerades även för att utvärdera effekten i ett tvåstegsdike då fler stormevent sker. Resultaten visade att ökad retentionstid for vatten, näringsämnen, och sediment teoretiskt kan ges genom att designa tvåstegsdiken med maximal terrassbredd och minimal terrasshöjd, samt med terrasser vinklade bort från mittfåran. Vegetation bör även behållas på terrasser och i mittfåran av tvåstegsdiket för att öka retentionstiden. Studien visade även att tvåstegs- dikets design har möjligheten att minska toppflöden vid stormevent, vilka kan förväntas öka i framtiden. Påverkan på transport av näringsämnen och sediment från fler framtida extrema hydrologiska event kräver ytterligare studier.

Diploma thesis deal with the issue revitalization of water stream. Assessment and design of revitalization is done for watercourse Osoblaha, situated in the cadastral territory Osoblaha nad Studnice by Osoblaha. In diploma thesis were designed several of revitalization measures such as stone backfill, willow fence, groyne, casting willow cuttings to supplement the vegetation on river‘s banks, fish shelter and wirestone baskets (gabions). In the given section was designed pool and also was there designed boulder slip, which will replace present downflow step. After designing was made hydrotechnical calculations to demostrate preservation runoff conditions of present stream condition.

This thesis is aimed at assessment of drainage conditions at the river Loucna in the cadastral area of Dasice. The examined section is 3,88 km long and runs through out of the city and in the city of Dasice. On the left bank of the river there are several historic buildings that are potentially at risk for 100 years of flow. Capacity assessment is performed using the 1D mathematical program HEC - RAS in which the flow model is created and the calculation of the flow rates for individual N - year flows. On the basis of the results of the program is conducted conceptual desing of flood protection measure. At the same time is conducted conceptual desing of fish ladder on the weir and a sluice closure on the intake for the race.