This thesis deals with a proposal for flood area in cadastral district of a town Hluk. Proposed area is defined from 12,805 to 15,495 rkm, total lenght of proposal is 2,69 km. Data for the creation of flood area of Hluk were provided by The Moravia River Basin, s.e. Brno. The analysis of flood area was done by using the computer program HEC - RAS. The final flood area for proposed flow Q100 was done in the computer program AutoCAD. The thesis is complemented by drawing documentation and photografic documentation. Key words: flood, HEC - RAS, transverse profile, the river Okluky

This thesis is focused to flood protection in Bělá nad Radbuzou. Flood protection is designed only for central part of this town, there are, in the central part, most interesting buildings, like city office, shopes, hotel. Protection of buildings, situated in pheriphery in this town are not solved, because of economic and esthetic reasons. Purpose of this work is solution of flood protection in downtown, in range of documentation for area project. This thesis is focused in the first step to detected floods lines and submersion of buildings. In this work are solved suitable grounds for find correct trace of flood protection. Next step is hydrotechnical modelling of water surface for Q5, Q20, and mainly for Q100. Then are solved height and direction of flood protection. In this work are solved statics paramerters of flood protection and separately is created designing part. Economic part and calculating acreage is solved too. In conclusion is complex valorization of flood defences and calculating of total costs. This work were solved on foundations of hydrologic and geodetic data. Data were proces in softwares HEC-RAS, ArcGis, Kros plus and AutoCad. Contribution of this thesis si solving and calculating range flood protection for this town. The main purpose is solved direction and height of flood protection and calculating finance part of this construction. The results of this thesis shows a comprehensive summary about flood protection in Bělá nad Radbuzou.

During the past decade, a series of record flood stages have occurred along the Tisza River, resulting in extensive damage and displacing the local floodplain population. Previous research on the Tisza River in Hungary showed increases in flood stages for fixed discharges (above bankfull). These results suggest that a loss of conveyance has taken place on the Tisza River, contributing to recent record flood levels. In order to assess the potential causes of flood conveyance losses, new hydrological and geospatial data were obtained from the Hungarian Federal Hydrological Authority (VITUKI) in order to develop hydrodynamic models for two reference conditions, 1979 and 1999, along two study reaches on the Middle Tisza River. In addition to these models of actual conditions at each time step (i.e., "retro-models"), four "scenario models" were developed in order to test the individual impacts of each of the hypothesized causal mechanisms: 1) channel geometry, 2) levees, 3) floodplain roughness (land cover), and (4) channel roughness. Comparison of the models for actual conditions ("retro-model") and the scenario models allows for quantitative assessments of the impacts of each of these parameters on flood conveyance. In addition to these four scenario models, an additional land cover scenario-model was created to further assess the impact of floodplain roughness on stage. Assessment of the two retro-models showed changes in flood stage along both study reaches over the 20-year time step. Along the upper study reach, changes in stage ranged between 0.64 and 1.64 m. On the lower study reach, changes in stage ranged from 0 to 1.75 m. These changes in stage were larger on average than changes in stage previously detected by Venzcel, 2008. Contributions from the channel geometry scenario model were significant on the upper study reach where channel geometry decreased flood stage by up to 0.58 m at Kisköre over the 20-year time step. This was attributed to the dam that was constructed immediately upstream from the Kisköre gauge on the upper study reach. Construction of a dam would cause incision downstream, and therefore, a decrease in flood stage over time due to channel geometry. On the lower study reach, change in stage due to channel geometry was negligible. Contributions from the levee scenario model were negligible on both the upper and lower study reach with a maximum change in stage over the 20-year time step at only 0.11 m. However, during the time step analyzed, no significant change in levee configuration occurred. Changes in stage due to changes in land cover were also negligible along both study reaches. An additional land cover scenario model was created to assess the impact of land cover change on modern flood levels. This scenario model set Manning's n values for floodplain roughness to 0.04, which approximates roughness for pasture and cropland. This scenario model showed that flood stages will decrease by 0.34-0.40 m, but only if the entire floodplain is converted from woodland to pasture/cropland. Channel roughness accounted for the majority of change in stage during the 20-year time step. Along the upper study reach, channel roughness accounted for an average of 1.51 m of change over the 20-year time step. On the lower study reach, channel roughness accounted for 1.03 m of change. Change in the stage/discharge relationship is the best explanation for changes in stage due to channel roughness. Most likely, the channel did not experience such a large change in roughness during the 20-year time step. Instead, the two flood years used in this analysis were different "types" of floods (with differing degrees of hysteresis), and the stage/discharge relationships could not be easily compared. Comparing these two floods may have exaggerated the total change in stage between the two retro-models. Backwater effects are a likely explanation for the change in hysteresis between the two flood years.

Dam failure mechanism produces the rapidly varied unsteady flow situation and the appropriate analysis to determine the flow condition is necessary. Over the world, more than 80,000 dams were constructed. There have been more than 200 distinguished dam failures occurred within the twentieth century. The history of dam construction exists together with the probability of dam failure causing casualties and catastrophic situations. As climate change effect has caused the change in flow situations, the safety concern in the dam is also necessary. Casualties and damages due to dam break events depend upon the depth, flow velocity, population distribution as per geography and warning time related to the time to reach the peak flow to the downstream areas. Prediction of actual breaching scenario is not certain and is related to the geographical and geological features of the site, embankment type, type of breach, reservoir storage and flow conditions. Estimating the accurate breaching scenarios and modeling of the dam break situation to characterize the hydrodynamic risk is necessary. Among the numerous techniques of modeling dam break situation, this study focused on the use of HEC-RAS for analyzing the dam break situation. Most of the simulation of a dam break situation used one-dimensional analysis to solve flow conditions after the break of the dam. The Latest development of HEC-RAS 2D capabilities is also used in conjunction with 1D HEC-RAS dam break analysis to compare and explore both analysis capabilities of HEC-RAS. The effect of HEC-RAS simulation altering the breaching conditions is analyzed for the dam failure case of Big Bay dam located in Lamar County, Mississippi. The study area is chosen to obtain the simulation of piping dam failure, which was the real cause of the dam failure event. In addition, the overtopping failure parameters established by the different breaching regression equations were analyzed. Results obtained with both one- dimensional and two- dimensional analysis is compared along with the modeling procedure and concept of analysis. From the analysis, it is found that the time of peak water surface elevation and its magnitude is responsible in determining the extent of vulnerable areas to the dam break scenarios. The present study showed the variation in peak flow condition between different breach parameters. Breach bottom width found to be more sensitive parameters in dam failure events. HEC-RAS analysis is found to be suitable to predict the uncertain hydraulic behavior of dam break situation.

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Baigiamąjame darbe analizuojama galimybė netradiciniais Lietuvoje metodais (naudojant hidraulinį modelį) įvertinti reguliuoto upelio deformacijų įtaką jo pralaidumui, kadangi dažnai atsitinka taip, kad numatomos nemažos lėšos remontui, kai tuo tarpu upelio pralaidumo charakteristikos dar pakankamai geros. Modelio kalibravimui ir hidrauliniam modeliavimui naudojami realiai išmatuoti ir projektiniai duomenys. Hidrodinaminis modelis sudaromas tuo tikslu, kad būtų galima patikrinti pasirinkto upelio ruožo vagos ir tame ruože esančios pralaidos matmenis kaip pakraštines sąlygas, naudojant iš projekto paimtais hidrologiniais skaičiavimais nustatytus debitus ir įvertinti tėkmės sąlygas esant projektinėms geometrinėms charakteristikoms ir realiai išmatuotoms dabartinėje upelio būklėje. Atliekant natūrinius tyrimus buvo nustatinėjamos šios reguliuoto upelio charakteristikos: debitas, vandens lygiai, vandens paviršiaus nuolydis, šiurkštumo koeficientai; griovyje esančių pralaidų būklė. Darbo tikslas - panaudojant programą HEC-RAS sukurti pasirinkto reguliuoto upelio ruožo hidrodinaminį modelį ir patikrinti griovio ir pralaidos pralaidumo pokyčius lyginant projektinius ir natūroje išmatuotus parametrus. Tyrimo uždaviniai: 1. Literatūros apžvalgoje išnagrinėti atvirų vagų hidraulinio modeliavimo metodus, programinę įrangą ir praktinio taikymo atvejus. 2. Išmokti dirbti su programine įranga HEC-RAS. 3. Sukurti pasirinkto upelio ruožo hidrodinaminį modelį ir atlikti... [toliau žr. visą tekstą] / Final work analyzes the possibility to evaluate the impact of deformations of regulated stream on its capacity by the methods that are non-traditional in Lithuania (using a hydraulic model), as often is the case when substantial funding is provided for repair, while the stream capacity characteristics are still good enough. The actual measured and projected data is used for model calibration and hydraulic modelling. Creation of hydrodynamic model aims to verify the dimensions of bed and culverts in the selected stream section using the discharges based on the project hydrological calculations as peripheral conditions and to evaluate the flow conditions at the projected geometric characteristics and at those measured in the current state of the stream. Field research determined the following characteristics of the stream: yield, water levels, water surface slope, roughness coefficients; condition of the equipment in the ditch: state of culverts. Aim of the work – by modelling the established flow to determine the longitudinal water level profiles for the both cases and to evaluate the differences. Results of the work allow stating that lateral trench deformations have negligible impact on the flow conditions. Objectives of the research: 1. to analyze the hydraulic modelling techniques of open beds, software and cases of practical application; 2. to learn working with the software HEC-RAS; 3. to create hydrodynamic model of the selected stream... [to full text]

Made available in DSpace on 2015-05-14T12:09:20Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2940613 bytes, checksum: c2ca77347eb4c70d77a6a159866db8b4 (MD5) Previous issue date: 2013-06-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The intense population growth of the last decades has shown the lack of urban planning of brazilian cities. The disordered urbanization process involves directly in increased impervious areas, changing natural conditions and interfering in hydrological cycle. The metropolitan area of the João Pessoa city, Paraíba, has suffered from urban expansion without urban planning and has seen various impacts, such as floods. In the region of the river Cuiá basin, located in southern coastline of Paraíba, in the municipality of João Pessoa, between the UTM coordinates 9.210.000N/302.000E e 9200.00N/292.000E, such events have been repeated in periods of heavier rainfall. In this sense, the application of hydrological models has been recommended for prediction of impacts on water resources and assists in the decision making of managers. Thus, this study aims to estimate the impacts of urbanization on flooding in the river Cuiá basin. For this, we used the hydrological models IPH II and HEC-RAS and considered three urbanization scenarios (current, trend and critic), defined based on certain percentages of soil sealing and urban occupation. The rainfall-runoff simulations were performed considering rainfall with return period of 10, 50 and 100 years allowed us to estimate the impacts on the flows generated, on peak times and on floodplains of the basin. With the simulation results, it was found that the lower frequency rainfall results in peak flow up to 80% higher than the highest frequency. Under the same conditions, peak times were reduced on average by 10% when compared to the critical and current scenarios. The flood simulations generated information that allowed create the flood maps. Considering the potencial of flood scenarios more critical and less frequent events, floodplains can be as much as 13% higher than in the current scenario. / O intenso crescimento populacional das ultimas décadas tem evidenciado a falta de planejamento urbano das cidades brasileiras. O processo de urbanização desordenado implica diretamente no aumento de áreas impermeáveis, modificando condições naturais do meio e interferindo no ciclo hidrológico. A região metropolitana da cidade de João Pessoa, Paraíba, tem sofrido com a expansão urbana sem planejamento e, por consequência, visualizado vários impactos, como as inundações e os alagamentos. Na bacia hidrográfica do rio Cuiá, localizada no sul do litoral paraibano, no município de João Pessoa, entre as coordenadas UTM 9.210.000N/302.000E e 9200.00N/292.000E, eventos desse tipo são constantemente verificados nos períodos de chuvas mais intensas. Nesses casos, a aplicação de modelos hidrológicos tem sido recomendada para previsão dos impactos sobre os recursos hídricos e auxiliar no processo de tomada de decisão por parte dos gestores. Nesse sentido, este estudo tem como objetivo estimar os impactos da urbanização sobre as inundações urbanas na bacia hidrográfica do rio Cuiá. Para isso, utilizou-se os modelos hidrológicos IPH II e HEC-RAS, considerando três cenários de urbanização (atual, tendencial e crítico), definidos com base em percentuais de impermeabilização do solo e de áreas de ocupação urbana. As simulações chuva-vazão foram realizadas considerando chuvas com tempos de retorno de 10, 50 e 100 anos e permitiram estimar os impactos sobre as vazões geradas, sobre os tempos de pico e sobre áreas inundáveis da bacia. Com os resultados das simulações, verificou-se que as vazões máximas foram até 80% maiores quando resultantes de chuvas de menor frequência, do que de maior frequência. Nessas mesmas condições, o tempo do pico foi reduzido, em média, em 10% quando comparados os cenários crítico e atual. As simulações das inundações geraram informações que permitiram confeccionar os mapas de inundações. Ao se considerar o potencial das inundações nos cenários mais críticos e para eventos menos frequentes, as áreas inundáveis podem chegar a ser até 13% maiores do que no cenário atual.

The water level at Hjälta power station in Faxälven varies depending on the water flow that passes through the power station. The varying water level causes head losses, lesser energy generation and loss of income. The varying water level is caused by a short but narrow and shallow part of the river, known as Klockarforsen. To increase the water flow and decrease the resulting head losses, it is possible to dredge the stream bed in Klockarforsen in order to achieve a greater depth.  By using a sonar to map the bathymetry in Klockarforsen, it has been possible to create a model of this part of the river. The model has been constructed and processed in ArcGIS and HEC-RAS, in order to examine how a dredging would affect the water level, head losses, energy generation, income and retention water levels.  The results show that a dredging to a depth of four or six meters could raise the water level and the head height at Hjälta power station with an average of 0.32 and 0.41 meters, respectively. During the period between 2014-2019, 1.11-3.84 GWh more energy would have been generated annually if Klockarforsen had been dredged. Which means that the income for the power station would have increased by between MSEK 0.39-1.3 per year. The increased energy generation and income are considerable, but in terms of how much energy and income is generated annually, the figures are more modest. The energy production and income increase by between 0.13-0.3 percent annually.

Dams and power plants in watercourses pose a serious threat to diversity and aquatic species as they fragment habitats and create barriers. New legislation aims to facilitate the restoration of watercourses and in many places, various fish passages have been built. Evaluations of these are important in order to ensure that the desired function has been achieved. At Näkten regulation dam in Jämtland, Sweden, a combined technical and natural fishway has been built to enable migration for trout and grayling. The purpose of the study is to find out whether the technical solution has had suitable flows and gate settings for the fish that one wanted to enable migration for. To investigate this, unsteady flow analyzes were performedin HEC-RAS and then compared to field measurements as well as information from the dam owner. The results show that the gate during the study period has not been set according to recommended settings and that the flows at times have been too high to be suitable for migration. However, comparison with field measurements and previous calculations suggest that the modeled flows do not match reality but are too high in the model. The conclusion is therefore that further modeling and a more thorough comparison with field measurements is recommended to create reliable results and that one then possibly can adjust the settings on the gates. / Dammar och kraftverk i vattendrag utgör ett allvarligt hot mot diversiteten och vattenlevande arter då den fragmenterar livsmiljöer och skapar hinder. Nya lagstiftningar ska underlätta för återställning av vattendrag och på många platser har olika fiskpassager byggts. Utvärderingar av dessa är viktiga så att man kan säkerställa att önskad funktion är uppnådd. Vid Näktens regleringsdamm i Jämtlands län har ett kombinerat tekniskt oc hnaturlikt omlöp byggts för att åter möjliggöra vandring för öring och harr. Studiens syfte är att ta reda på om den tekniska lösningen har haft lämpliga flöden och luckinställningar för de fiskar som man velat möjliggöra vandring för. För att undersöka detta har flödesmodelleringar gjorts i programmet HEC-RAS och fältmätningar samt uppgifter från dammägaren har använts som referens. Resultaten visar att luckan under studieperioden inte varit inställd efter rekommenderade inställningar och att flödena ha varit för höga för att vara lämplig för vandring. Dock tyder jämförelse med fältmätningar och tidigare beräkningar att flödena inte stämmer överens med verkligheten utan blir för höga i modellen. Slutsatsen blir därför att ytterligare modellering och en grundligare jämförelse med fältmätningar rekommenderas för att skapa tillförlitliga resultat och att man därefter eventuellt kan justera inställningarna på luckorna. / <p>2023-06-02</p>