Understanding the role of road networks in alteration of hydrological responses is crucial for maintaining the accessibility and durability of road infrastructures. Road construction is one of the most common man made disturbances to a landscape. However, still the quantitative role of road topographical and geo-morphological properties on the hydrological response of storms in catchments is only partially understood. The aim of this study was to use new methods to estimate and quantify the flood hazard probability with reference to the most influential physical catchment descriptors and road characteristics. In addition physical based modelling was used to estimate the effect of road topography on the hydrological responses of watersheds to storms with different intensities. A simple method was developed and discussed to address the most susceptible locations to flooding along the roads. Multivariate statistical analysis (PLS) employed to quantify the flood risk probability in the road-stream crossings concerning the correlation between the quantities of the physical catchment descriptors and occurrence/absence of flooding. The most influential factors in describing the probability of flooding along the roads were topographic wetness index, soil properties, road density and channel slopes. A detailed study of simulated flow duration curves showed differences between 20 watersheds for three different storms based on a digital elevation data with and without roads. An increase in peak flow and reduced delay occurred with increased storm intensity. However, the impact of the roads was much smaller and only possible to identify by detailed examination of statistical descriptors. / <p>QC 20140214</p>

Omställningen till förnyelsebara energikällor innebär att bland annat elproduktionen från vattenkraftverken måste utökas. I Sverige är vattenkraften redan etablerad och platser att bygga nya vattenkraftverk på är få. Därmed är det viktigt att ta vara på de vattenkraftverk som är i drift och om möjligt utöka elproduktionen i de kraftverken. En utökning av elproduktionen i ett vattenkraftverk kan bland annat genomföras genom att rensa och bredda utloppskanalen vilket ökar fallhöjden. Målet för den här studien var att finna den ekonomiskt mest optimala volymen att rensa i utloppskanalen från Rottnens vattenkraftverk för att utöka elproduktionen. Rottnadammen är placerad i anslutning till Rottnens vattenkraftverk och ska eventuellt rivas. En dammrivning medför miljökonsekvenser. Målet från studien var att undersöka vilka miljökonsekvenser en dammrivning medför. För beräkningen av elproduktionseffektiviseringen i Rottnens vattenkraftverk användes programvaran HEC-RAS. HEC-RAS användes för att simulera hur vatten- nivån i utloppskanalen förändras när olika volymer har rensats. För att undersöka miljökonsekvenser av en dammrivning genomfördes en litteraturstudie. Elproduktionsökning i Rottnens vattenkraftverk är möjlig genom rensningar i utloppskanalen i samband med att vattenintaget till Rottneros bruk flyttas från Rottnens vattenkraftverk till sjön Fryken. Det är ekonomiskt mest optimalt att rensa cirka 20 000 m3 vilket medför en elproduktionsökning på ungefär 1,1 GWh/år för ett statistiskt normalår. Inkomsten till följd av elproduktionsökningen är cirka 750 Kkr/år. Investeringskostnaden för en rensning på 20 000 m3 är ungefär 7 300 Kkr. Återbetalningstiden för investeringen är ungefär 16 år. Flytten av vattenintaget innebär att flödet som i dagsläget tas ut från bruket vid Rottnens kraftverk istället kan adderas till flödet som går genom vattenkraftverket och därmed utöka elproduktionen ytterligare. Med det extra flödet skulle elproduktionsökningen i Rottnens vattenkraftverk bli ungefär 1,7 GWh/år för rensning av volymen 20 000 m3 vilket skulle bidra till en inkomst på cirka 1 200 Kkr/år.Resultatet från litteraturstudien visar att det är viktigt att undersöka miljö- konsekvenser av en dammrivning för att kunna göra miljömedvetna val. För en eventuell rivning av Rottnadammen är det viktigt att ta hänsyn till vilken tid på året som rivningen sker för att minimera mängden organiskt material som flödar ut i sjön Fryken. Hastigheten av tömningen är också en viktig faktor för att dammrivningen ska medföra så liten påverkan som möjligt på ekosystemen i och omkring dammen.

Hydrology Modeling using HEC-HMS (Hydrological Engineering Centre-Hydrologic Modeling System) is accepted globally for event-based or continuous simulation of the rainfall-runoff operation. Similarly, Machine learning is a fast-growing discipline that offers numerous alternatives suitable for hydrology research's high demands and limitations. Conventional and process-based models such as HEC-HMS are typically created at specific spatiotemporal scales and do not easily fit the diversified and complex input parameters. Therefore, in this research, the effectiveness of Random Forest, a machine learning model, was compared with HEC-HMS for the rainfall-runoff process. In addition, Point gauge observations have historically been the primary source of the necessary rainfall data for hydrologic models. However, point gauge observation does not provide accurate information on rainfall's spatial and temporal variability, which is vital for hydrological models. Therefore, this study also evaluates the performance of satellite and radar precipitation products for hydrological analysis. The results revealed that integrated Machine Learning and physical-based model could provide more confidence in rainfall-runoff and flood depth prediction. Similarly, the study revealed that radar data performance was superior to the gauging station's rainfall data for the hydrologic analysis in large watersheds. The discussions in this research will encourage researchers and system managers to improve current rainfall-runoff simulation models by application of Machine learning and radar rainfall data.

No description available.

Presented in this thesis is a case study of two study watersheds located in south central Virginia. For each, a HEC-HMS event-based hydrologic model was constructed to simulate the rainfall-runoff response from the Probable Maximum Storm (PMS), the theoretical worst-case meteorological event that is capable of occurring over a particular region. The primary goal of these simulations was to obtain discharge hydrographs associated with the Probable Maximum Flood (PMF) at key locations in each of the watersheds. These hydrographs were subsequently used to develop flood inundation maps of the study areas and to characterize sediment transport phenomena in the study reaches under severe flooding conditions. To build the hydrologic basin models, ArcHydro, HEC-GeoHMS and ArcGIS were employed to assimilate the substantial amount of input data and to extract the pertinent modeling parameters required for the selected simulation methods. In this, the SCS Loss and Transform Methods, along with the Muskingum Routing Method, were adopted for the HEC-HMS simulations. Once completed, the basin models were calibrated through a comparison of simulated design storm flows to frequency discharge estimates obtained with regional regression techniques and a flood frequency analysis. The models were then used to simulate their respective PMS events, which were developed following recommendations from the Hydrometeorological Branch of the National Weather Service and the U.S. Army Corps of Engineers. Descriptions of each of the study sites, explanations of the modeling theory and development methodologies, and discussions of the modeling results are all detailed within. / Master of Science

A flood inundation study is presented for a watershed located in south central Virginia. A HEC-RAS hydrodynamic model of the main river network was developed to assess the impact of a number of hydrologic events, including the Probable Maximum Flood (PMF), in the area of interest. The primary goal of the study was to transform discharge hydrographs produced by HEC-HMS, an event-based hydrologic model, into water surface elevations and flood inundation spatial extents. Initially, a river terrain model was constructed using data from publicly available sources and filed survey campaigns. HEC-GeoRAS and ArcGIS were used to document and integrate the considerable amount of data required for building the model. Then, a calibration process was performed using stage-discharge predictor curves. The HEC-RAS unsteady flow component was employed for routing the discharge hydrographs through the modeled river network. Flood inundation maps, as well as longitudinal water surface elevation and channel velocity profiles were generated for the study reaches. As part of the flood inundation study, an uncertainty quantification analysis was carried out on the boundary roughness of the floodplains. The objective was to measure the extent to which flood inundated areas, water surface elevations, and channel velocities were influenced by variations on this empirically-based model coefficient. Finally, the impact of various hydraulic characteristics of the modeled river on the sediment transport process is examined. This characterization is intended to provide a better understanding of a subsequent sediment transport modeling effort to be performed under severe flooding conditions. / Master of Science

The primary objective of this thesis is to develop hydrologic and hydraulic models for the Soap Creek Watershed, IA for the evaluation of alternative flood mitigation strategies and the analysis of the differences between hydrologic and hydraulic routing methods. In 2008, the state of Iowa suffered a disastrous flood that caused extensive damage to homes, agricultural lands, commercial property, and public infrastructures. To reduce the flood damage across Iowa, the U.S. Department of Housing and Urban Development (HUD) awarded funds to the Iowa Flood Center and IIHR-Hydroscience &Engineering at the University of Iowa to conduct the Iowa Watersheds Project. The Soap Creek Watershed was selected as one of the study areas because this region has suffered frequent severe floods over the past century and because local landowners have organized to construct over 130 flood detention ponds within it since 1985. As part of the Iowa Watersheds Project, we developed a hydrologic model using the U.S. Army Corps of Engineers’ (USACE) Hydrologic Center’s hydrologic Modeling System (HEC-HMS). We used the hydrologic model to evaluate the effectiveness of the existing flood mitigation structures with respect to discharge and to identify the high runoff potential areas. We also investigated the potential impact of two additional flood mitigation practices within the Soap Creek Watershed by utilizing the hydrologic model, which includes changing the land use and improving the soil quality. The HEC-HMS model simulated 24-hour design storms with different return periods, including 10, 25, 50, and 100 year. The results from modeling four design storms revealed that all three practices can reduce the peak discharge at different levels. The existing detention ponds were shown to reduce the peak discharge by 28% to 40% depending on the choice of observed locations and design storms. However, changing the land use can reduce the peak discharge by an average of only 1.0 %, whereas improving the soil quality can result in an average of 15 % reduction. Additionally, we designed a hydraulic model using the United States Army Corps of Engineers’ (USACE) Hydrologic Engineering Center’s River Analysis System (HEC- RAS) to perform a comparative evaluation of hydrologic and hydraulic routing methods. The hydrologic routing method employed in this study is the Muskingum Routing method. We compare the historical and design storms between HEC-HMS, HEC-RAS, and observed stage hydrographs and take the hydrograph timing, shape, and magnitude into account. Our results indicate that the hydraulic routing method simulates the hydrograph shape more effectively in this case.

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2015-10-21T19:45:51Z No. of bitstreams: 2 Tese - FERNANDA POSCH CIAMB - 2015.pdf: 5434344 bytes, checksum: 36b420ce99a173b1c3ac6590942d2829 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-22T12:38:06Z (GMT) No. of bitstreams: 2 Tese - FERNANDA POSCH CIAMB - 2015.pdf: 5434344 bytes, checksum: 36b420ce99a173b1c3ac6590942d2829 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-10-22T12:38:06Z (GMT). No. of bitstreams: 2 Tese - FERNANDA POSCH CIAMB - 2015.pdf: 5434344 bytes, checksum: 36b420ce99a173b1c3ac6590942d2829 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-03-20 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The study began with a technical approach to the development of a methodology to determine the support capacity of urban streams exposed to erosion, based on the identification of the maximum limit flow, without the channel overflowing, as determining factor of drag stress and of processes of production, transport and deposition of sediments. During the first field work stage, we defined a longitudinal section of the Samambaia Stream, located in the city of Goiânia, Goiás State Capital, Brazil, to collect soil samples, perform infiltration tests and monitor the level of variation water, with the HOBO U20 equipment. The laboratory stage consisted of testing of physical characterization of soil and runoff simulation using the Inderbitzen apparatus, to determine sediment production rate. The information obtained in these two phases, together with the data coming from the bathymetric surveys of the cross sections and the topographic survey of margins and of the adjacent areas of said channel have been used as input parameters for the simulation performed with the use of the 1D model Hydrologic Engineering Center - River Analysis System (HEC-RAS), version 4.1, in order to know the support capacity of the Samambaia stream. Then was included in the research problem, an argument involving the social and environmental impacts caused by the activities of Civil Engineering, performing an epistemological reflection, extrapolating the focus exclusively technical, to the assimilation of new insights into the interactions between the Civil Engineer and nature, looking for evidence of a possible change to a paradigm that will contribute to the reduction of urban environmental vulnerability. Thus, qualitative research was carried out through semi-structured interviews with sample composed by by professionals working in the Engineering Civil and at the same time, teachers of federal institutions of higher education, forming new professionals in this area. Data analysis was referenced, especially in the works of Thomas Kuhn and also used the software Web Qualitative Data Analysis (WebQDA), by favoring the structuring and the categorization process. The results indicated that the current model adopted by the Civil Engineering is unable to simultaneously meet the expectation of the population, in relation to better living conditions in urban areas, and respond positively to social and environmental challenges. Up until today, conflicts in face of these challenges, constitute indicators of the appearing of anomalies, however, there isn’t a setup for a paradigmatic crisis. / O estudo sobre a capacidade de suporte de córregos urbanos foi iniciado com uma abordagem técnica para a formulação de uma metodologia capaz de determinar a capacidade de suporte de córregos urbanos sujeitos a processos erosivos, embasada na identificação da vazão máxima limite, sem extravasamento do canal, como parâmetro determinante da tensão de arraste e dos processos de produção, transporte e deposição de sedimentos. Durante a primeira etapa de trabalho de campo, definiu-se um trecho longitudinal do Córrego Samambaia, localizado na Cidade de Goiânia, Capital do Estado de Goiás, Brasil, para se coletar amostras de solos, realizar ensaios de infiltração e monitorar a variação de nível de água, com o equipamento HOBO U20. A etapa de laboratório constituiu-se da realização de ensaios de caracterização física do solo e de simulação de escoamento superficial com o uso do Aparelho de Inderbitzen, para se determinar as taxas de produção de sedimentos. As informações conseguidas nessas duas fases, somadas aos dados provenientes do levantamento batimétrico das seções transversais, e plani-altimétrico das margens e áreas adjacentes do referido canal, foram utilizadas como parâmetros de entrada para a simulação, realizada com o uso do modelo 1D Hydrologic Engineering Center – River Analysis System (HEC-RAS), versão 4.1, de modo a se conhecer a capacidade de suporte do Córrego Samambaia. A análise desses dados fez surgir uma nova problemática: os impactos socioambientais provocados pelas atividades da Engenharia Civil, que acendeu uma reflexão epistemológica, extrapolando o enfoque, exclusivamente técnico, sobre as interações entre o Engenheiro Civil o ambiente, em busca de indícios de uma possível mudança para um paradigma que venha colaborar com a redução da vulnerabilidade socioambiental urbana. Desse modo, foram realizadas pesquisas qualitativas, por meio de entrevistas semiestruturadas com um universo amostral constituído por profissionais atuantes na Engenharia Civil e, ao mesmo tempo, docentes de instituições federais de ensino superior, formadoras de novos profissionais desta área. A análise dos dados foi referenciada, principalmente, nas obras de Tomas Kuhn e, como instrumento de análise foi empregado o software Web Qualitative Data Analysis (WebQDA), por favorecer a organização dos dados e o processo de categorização. Os resultados indicaram que o atual modelo adotado pela Engenharia Civil não é capaz de, simultaneamente, atender a expectativa da população, com relação às melhores condições de vida no meio urbano, e responder, de forma positiva, os desafios socioambientais. Concluimos que os conflitos, perante os desafios ambientais, constituem-se indicadores do surgimento de anomalias, no entanto, não há, ainda, a configuração de uma crise paradigmática.

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-01-27T17:33:00Z No. of bitstreams: 2 Dissertação - Kamila Almeida dos Santos - 2015.pdf: 15571589 bytes, checksum: 4409744d6740773c19322b95c96e75cd (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-01-28T11:52:55Z (GMT) No. of bitstreams: 2 Dissertação - Kamila Almeida dos Santos - 2015.pdf: 15571589 bytes, checksum: 4409744d6740773c19322b95c96e75cd (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-01-28T11:52:55Z (GMT). No. of bitstreams: 2 Dissertação - Kamila Almeida dos Santos - 2015.pdf: 15571589 bytes, checksum: 4409744d6740773c19322b95c96e75cd (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-12-10 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The urbanization issues is taking place in Brazilian cities has proved disorganized and thus the floods are becoming a recurring phenomenon. The growth of waterproofing in urban land decreases the amount of infiltrated water in the soil during the rainy season, the rivers might otherwise not conform the water demand in the channels in addition to receive a lot of water runoff In this context the hydrodynamic modeling is an important tool to assess the drainage systems and predict the effects of flooding. This study was applied to the watershed of Ribeirão Anicuns in Goiania, where a considerable part of the basin is in an urban area. Using the hydrodynamic model HECRAS were created various flood scenarios with return periods of 15, 25, 50 and 100 years for the project rainfall; there was aid of a geographic information system, using ArcMap 10.0 to the high-resolution orthophoto city and DEM made from airborne laser scanner, with this material extracted the geometry of the basin. In hydrodynamic modeling crafted the model was run in unsteady flow considering the full Saint Venant equation. In addition to the hydrodynamic modeling was carried out a simulation on the INPE simplified model called HAND, which turned out to be an inexpensive tool, easily accessible and with quality results. With the results obtained (flood hydrograph and flood patches concerning the different return times) flood areas were shown in different scenarios created, and you can compare them. The results showed that the flood spot along the basin have become significantly larger as the return periods grow. In urbanized streams were no major changes than the changes that occurred in streams away from the urban area. Streams that are outside the urbanized area focuses on the alert, they are natural streams and showed that will not support the volume of water resulting from this work. / O processo de urbanização que está ocorrendo nas cidades brasileiras tem se mostrado desorganizado e com isso as inundações estão se tornando um fenômeno recorrente. O crescimento da impermeabilização no solo urbano diminui a quantidade de água infiltrada no solo durante o período de chuva, os córregos não conseguem suprir a demanda da água nos canais, além de receber do escoamento superficial uma grande quantidade. Nesse contexto a modelagem hidrodinâmica é uma ferramenta importante para avaliar os sistemas de drenagens e prever os efeitos da inundação. Dessa forma o presente trabalho foi aplicado na bacia hidrográfica do Ribeirão Anicuns, no município de Goiânia, onde uma parte considerável da bacia se encontra em área urbanizada. Utilizando o modelo hidrodinâmico HEC-RAS foram criados vários cenários de inundação com os tempos de retorno de 15, 25, 50 e 100 anos para a chuva de projeto; houve auxílio de um Sistema de Informações Geográficas, utilizando o programa ArcMap 10.0 a ortofoto do município de alta resolução e o MDT feito a partir de laser scanner aerotransportado, com esse material se extraiu a geometria da bacia hidrográfica. Na modelagem hidrodinâmica trabalhada o modelo foi executardo no regime não permanente, considerando a equação de Saint Venant completa. Além da modelagem hidrodinâmica foi realizada uma simulação no modelo simplificado HAND do INPE, onde se mostrou ser uma ferramenta barata, de fácil acesso e com resultados de qualidade. Com os resultados obtidos (hidrogramas de cheia e manchas de inundação referente aos diferentes tempos de retorno) foram mostradas áreas de inundação nos diferentes cenários criados, sendo possível compara-los. Os resultados mostraram que a mancha de inundação ao longo da bacia se tornaram significativamente maiores a medida que os tempos de retorno cresciam. Nos córregos urbanizados houve mudanças maiores do que as mudanças que ocorreram nos córregos afastados do perímetro urbano. Nos córregos que estão fora da área urbanizada foca o alerta, são córregos naturais e mostraram que não suportarão o volume de água resultante deste trabalho.

Expansion of cities and major infrastructure projects lead to changes in land use and river flows. The probability of flooding is expected to increase in the future as a result of these changes in combination with climate change. Hydraulic models can be used to obtain simulated water levels to investigate the risk of flooding and identify areas that might potentially be flooded due to climate change. Since a model is a simplification of the reality it is important to be aware of a model’s uncertainties. A part of this study is therefore aimed to perform a sensitivity analysis to determine which parameter has the largest impact on the model result and has to be treated more careful and accurately. In this study the 1-dimensional flow model Hydrologic Engineering Center-River Analysis System (HEC-RAS) were assed to simulate predicted water levels within the studied river. Topographic data was used to draw cross sections in Geographic Information Systems (GIS) with additional tools of HEC-GeoRAS, in order to get information about the streams geometry. The purpose of doing a sensitivity analysis was attained by investigating changes of the model results when changing different input parameters. This work is based on a reach along Mora river, in Södertälje, Sweden, as a case study. The sensitivity analysis indicate that the number of cross sections has a significant effect when simulating water levels of low flows and that the absolute error of simulated water levels increases as the average spacing between cross sections increases. The second part of the study aims to examine the effects of climate change and how it will affect water levels for the studied river. The results of the study showed that simulated water levels with flows of 100, 200 and 500 years return periods stay within the river channel and do not indicate flooded areas. The results also showed that a backwater effect due to sea level rise would affect the water levels in the stream up to a specific critical point along the studied reach. The lower reach indicated results to contain more uncertain region, where floodplain delineation changed easily as the number of cross section was changed. It is therefore important to identify the areas where uncertainties can be more critical for the results. Because of the uncertainties associated to the model used, it is important to notice that the results of this work correspond particularly to the case study in Mora River. / Studien genomförs inom Ostlänken, som är den första delsträckan av en ny höghastighetsjärnväg mellan Järna och Linköping. Bebyggelse och stora infrastrukturprojekt kommer förändra markanvändning och flöden i vattendrag. I följd av dessa förändringar, tillsammans med framtidens förändrade klimat, kommer risken för översvämningar kunna öka. För att undersöka riskerna för översvämningar och kartlägga områden som riskerar att översvämmas är en hydraulisk modell ett verktyg som kan användas. Då en modell endast är en förenkling av verkligheten och påverkas av flera olika parametrar är det viktigt att vara medveten om modellers osäkerheter. För att få modellen att efterlikna verkligheten så bra som möjligt kan det vara bra att veta vilka parametrar som har störst inverkan på modellens resultat och som bör bearbetas mer noggrant. Därmed är en del av studiens syfte att göra en känslighetsanalys för att utreda vilka modellparametrar och indata som påverkar modellresultaten, med fokus på att analysera simulerade vattennivåer. Känslighetsanalysen utförs genom en fallstudie över Moraån, där den endimensionella flödesmodellen HEC-RAS används för att beräkna vattendragets vattennivåer. Den andra delen av studiens syfte är att undersöka om hur framtidens klimatförändringar kommer kunna påverka det studerade området. En effekt av framtidens förändrade klimat är stigande havsnivåer som leder till ökad risk för översvämning vid kustnära områden. Till följd av dämningseffekter kommer de stigande havsnivåerna även ge ökade vattennivåer uppströms vattendragen, och beroende på vattendragens egenskaper och geometri kommer vattendrag längs med kusten att påverkas på olika sätt. För att undersöka riskerna för översvämningar i ett framtida klimat har modeller med olika klimatscenarios byggts upp där stigande havsnivåer kombinerats med flöden av varierande återkomsttider.