Inundações são eventos cada vez mais freqüentes e a cada ano os prejuízos são maiores. Inicialmente o combate dos prejuízos das inundações se deu na forma de evitá-las através de medidas estruturais. Hoje esta forma de combate vem sendo substituída, ou complementada, por medidas chamadas resilientes, geralmente medidas não estruturais, onde o objetivo é evitar as conseqüências e prejuízos da inundação, e não a própria inundação. Índices para avaliação do risco e conseqüências de inundações são ferramentas importantes para o gerenciamento do risco, eles permitem avaliar o risco, suas conseqüências, e auxiliam no desenvolvimento de planos de combate. Neste trabalho é proposto um índice de perigo (IP) e um índice de resiliência (PWRI): o primeiro lida com a vulnerabilidade de pessoas expostas à corrente de água devido inundação, e o segundo tem o objetivo de avaliar a resiliência de uma região com relação a eventos extremos hidrológicos, onde o risco de inundação e a capacidade de gerenciamento de suas conseqüências são determinados. O índice de resiliência (PWRI), que avalia qualitativamente a resiliência de uma região, é composto por seis fatores: o evento natural causador do risco (Ameaça), a probabilidade de inundação devido ao evento natural (Vulnerabilidade), a quantidade de pessoas expostas (Exposição), avaliação das medidas de prevenção e preparação contra a inundação e suas conseqüências (Antes), medidas de combate direto (Durante) e medidas de reconstrução após o evento (Depois). Os fatores são agrupados em dois grupos, o primeiro envolve a avaliação do Risco (Ameaça, Vulnerabilidade e Exposição) e o segundo a avaliação do Gerenciamento do Risco (Antes, Durante e Depois). Os fatores Ameaça, Vulnerabilidade e Exposição são obtidos a partir da previsão de escoamento superficial, modelo digital de elevação e densidade populacional. Os fatores Antes, Durante e Depois são obtidos a partir de hipóteses estabelecidas para o ano em questão. Os resultados são apresentados em uma nova forma de visualização do índice e são realizadas comparações dos resultados obtidos com eventos de inundação recentes. O índice de resiliência identifica pontos com problemas de inundações, e sugere novos pontos que podem sofrer inundação e perdas com o aumento da impermeabilização do solo e alteração do padrão de precipitação. Para o índice de perigo (IP) é desenvolvido um modelo teórico, onde os resultados são comparados e validados com dados experimentais encontrados na literatura. São apresentadas algumas recomendações e formas de utilização para o índice de perigo. Esta pesquisa forma parte do projeto temático Assessment of Impacts and Vulnerability to Climate Change in Brazil and Strategies for Adaptation Options, FAPESP 2008/58161-1 pela componente Mitigation and adaptation measures of vulnerable communities to cope with water-related risks derived from climate change scenarios at river basins of Sao Carlos. / Floods are becoming more frequent and each year the losses are greater. Initially it was used structural measures to avoid the floods and consequently avoid the losses. Today this is being replaced or supplemented by resilient measures generally in form of non-structural measures where the goal is to avoid the losses and damages and not the flood itself. Indexes for assessing the hazard and flooding losses are important tools in the risk management and allow the assessment of the flooding consequences and development of action plans. This work proposes the hazard index and the resilience index: the first one deals with the vulnerability of people exposed to flooding water flow and the second evaluates the resilience of a region with respect hydrological events. The resilience index (PWRI) is formed by six factors: a natural event which causes the threat (Hazard), the flooding probability due the hazard (Vulnerability), exposed people (Exposure), assessment of pre-flood measures (Before), emergency management (During) and post flood reconstruction measures (After). These factors are grouped into two groups: Risk assessment (Hazard, Vulnerability and Exposure) and the Risk Management (Before, During and After). The Hazard, Vulnerability and Exposure factors are obtained from the predicted runoff, digital elevation model and population density. Before, During and After factors are obtained from hypothesis. The resilience index is developed and compared with known flooding points map. It is shown that new flooding points are expected with the increase of the urbanization and land impermeabilization. The second part of the work is the hazard index (IP). A theoretical model is developed to evaluate the forces and limit conditions where people are dragged by water flow. The critical points of velocity and water depth are determined with the model and compared to experimental data found in the literature. In the end some suggestion and recommendation are present.

Les risques naturels en montagne font l'objet de mesures de prévention, souvent liées à des démarches de prévision. Dans certaines situations, la prévision de la survenue d'évènements liés à ces risques, voire la simple connaissance des processus physiques qui leur est associé, constitue un enjeu scientifique important compte-tenu de la grande complexité et de la forte hétérogénéité de ce milieu. La connaissance des mécanismes de formation des crues rapides sur les petits bassins versants englacés, ainsi que la perspective de leur prévision, est un exemple de ces risques difficilement maitrisables. La diversité des facteurs influençant les débits des rivières, leur complexité individuelle ainsi que celle de la manière dont ils interagissent, la forte variabilité spatio-temporelle des conditions météorologiques de la montagne ainsi que les modifications ayant lieu sur le long terme en raison du changement climatique font que ce phénomène nécessite une étude approfondie mobilisant des compétences pluri-disciplinaires, allant de la mesure de terrain au développement de modèles numériques prenant en compte les divers phénomènes liés à ce risque. Cette thèse s'inscrit dans le cadre d'un projet mis en oeuvre en partenariat avec les collectivités locales oevrant dans la vallée de Chamonix, voué à apporter un appui scientifique à la maitrise de ce risque. Au sein de ce projet, cette thèse porte sur le développement et le déploiement d'un modèle hydrologique prenant en compte la neige et les glaciers. Ce modèle se veut avoir deux objectifs : 1) servir d'outil de recherche permettant par exemple d'exploiter les mesures de terrain réalisées, en les confrontant aux résultats produits par ce modèle, et plus généralement de servir d'outil d'étude et de compréhension du fonctionnement de ce bassin, et 2) servir d'outil d'aide à la prévision des crues, en étant en mesure de fournir une prévision des débits de l'Arve à Chamonix à partir des données de prévision météorologique. L'exploitation des possibilités toujours grandissantes de la modélisation à bases physiques fait également partie des objectifs de cette thèse. En particulier, l'utilisation d'un modèle de neige à bilan d'énergie permettant notamment une représentation détaillée de l'interaction neige-glace a été mise en oeuvre, associée à l'exploitation des nombreuses mesures de terrain pour une évaluation en profondeur des résultats du modèle. Enfin, un déploiement expérimental de ce modèle en prévision a eu lieu à la fin de cette thèse. / Natural hazards in mountain are subject to prevention measures, which often partly rely on a forecasting component. In some situations, forecasting these hazards and understanding their underlying physical processes is a major scientifical issue, considering the great complexity and the strong heterogeneity of these backgrounds. Knowing underlying mechanisms of flash-floods on little catchments with glacier cover, and the perspective to forecast be able to forecast it, is an example of these risks difficult to master. The diversity of contributions to river discharge, their individual complexity and the one of the way they interact, the strong spatio-temporal variability of meteorological conditions of mountain and long-terms modifications occuring due to climate change make that this phenomenon needs to be deeply studied within a plury- disciplinary work, going from terrain measurement to development of computationnal models taking into account the diversity of physical phenomenons relating to this risk. This thesis belongs to a research project conducted in collaboration with local authorities operating in the Chamonix Valley. The goal is to provide a scientific support to help managing this hazard. The role of this thesis in this research project is to develop, test and deploy an hydrologic model taking snow and ice into account. This model is intended to be used as a research tool among other research tools of this projects (terrain measurements for example) and also to be able to help forecasting floods, when being driven by forecast meteorological data. This thesis benefitted from the continuous development of new possibilities from physically-based simulation. We have used an energy-balance multi layer snowpack model that permits a detailled representation of glacier accumulation and melt, and snow-ice interaction. It was possible to perform a multi-criteria evaluation of the model, thanks to the numerous in-situ field measurements in the Arve valley, especially glaciers mass balance measurements. Finally, this model has been deployed and tested as a pre-operationnal forecast tool.

Inundações são eventos cada vez mais freqüentes e a cada ano os prejuízos são maiores. Inicialmente o combate dos prejuízos das inundações se deu na forma de evitá-las através de medidas estruturais. Hoje esta forma de combate vem sendo substituída, ou complementada, por medidas chamadas resilientes, geralmente medidas não estruturais, onde o objetivo é evitar as conseqüências e prejuízos da inundação, e não a própria inundação. Índices para avaliação do risco e conseqüências de inundações são ferramentas importantes para o gerenciamento do risco, eles permitem avaliar o risco, suas conseqüências, e auxiliam no desenvolvimento de planos de combate. Neste trabalho é proposto um índice de perigo (IP) e um índice de resiliência (PWRI): o primeiro lida com a vulnerabilidade de pessoas expostas à corrente de água devido inundação, e o segundo tem o objetivo de avaliar a resiliência de uma região com relação a eventos extremos hidrológicos, onde o risco de inundação e a capacidade de gerenciamento de suas conseqüências são determinados. O índice de resiliência (PWRI), que avalia qualitativamente a resiliência de uma região, é composto por seis fatores: o evento natural causador do risco (Ameaça), a probabilidade de inundação devido ao evento natural (Vulnerabilidade), a quantidade de pessoas expostas (Exposição), avaliação das medidas de prevenção e preparação contra a inundação e suas conseqüências (Antes), medidas de combate direto (Durante) e medidas de reconstrução após o evento (Depois). Os fatores são agrupados em dois grupos, o primeiro envolve a avaliação do Risco (Ameaça, Vulnerabilidade e Exposição) e o segundo a avaliação do Gerenciamento do Risco (Antes, Durante e Depois). Os fatores Ameaça, Vulnerabilidade e Exposição são obtidos a partir da previsão de escoamento superficial, modelo digital de elevação e densidade populacional. Os fatores Antes, Durante e Depois são obtidos a partir de hipóteses estabelecidas para o ano em questão. Os resultados são apresentados em uma nova forma de visualização do índice e são realizadas comparações dos resultados obtidos com eventos de inundação recentes. O índice de resiliência identifica pontos com problemas de inundações, e sugere novos pontos que podem sofrer inundação e perdas com o aumento da impermeabilização do solo e alteração do padrão de precipitação. Para o índice de perigo (IP) é desenvolvido um modelo teórico, onde os resultados são comparados e validados com dados experimentais encontrados na literatura. São apresentadas algumas recomendações e formas de utilização para o índice de perigo. Esta pesquisa forma parte do projeto temático Assessment of Impacts and Vulnerability to Climate Change in Brazil and Strategies for Adaptation Options, FAPESP 2008/58161-1 pela componente Mitigation and adaptation measures of vulnerable communities to cope with water-related risks derived from climate change scenarios at river basins of Sao Carlos. / Floods are becoming more frequent and each year the losses are greater. Initially it was used structural measures to avoid the floods and consequently avoid the losses. Today this is being replaced or supplemented by resilient measures generally in form of non-structural measures where the goal is to avoid the losses and damages and not the flood itself. Indexes for assessing the hazard and flooding losses are important tools in the risk management and allow the assessment of the flooding consequences and development of action plans. This work proposes the hazard index and the resilience index: the first one deals with the vulnerability of people exposed to flooding water flow and the second evaluates the resilience of a region with respect hydrological events. The resilience index (PWRI) is formed by six factors: a natural event which causes the threat (Hazard), the flooding probability due the hazard (Vulnerability), exposed people (Exposure), assessment of pre-flood measures (Before), emergency management (During) and post flood reconstruction measures (After). These factors are grouped into two groups: Risk assessment (Hazard, Vulnerability and Exposure) and the Risk Management (Before, During and After). The Hazard, Vulnerability and Exposure factors are obtained from the predicted runoff, digital elevation model and population density. Before, During and After factors are obtained from hypothesis. The resilience index is developed and compared with known flooding points map. It is shown that new flooding points are expected with the increase of the urbanization and land impermeabilization. The second part of the work is the hazard index (IP). A theoretical model is developed to evaluate the forces and limit conditions where people are dragged by water flow. The critical points of velocity and water depth are determined with the model and compared to experimental data found in the literature. In the end some suggestion and recommendation are present.

No description available.

In a changing climate with an increasing risk of flooding, developing a sustainable approach to flood management is paramount. Sustainable Drainage Systems (SuDS) present a change in thinking with regards to drainage; storing water in the urban environment as opposed to rapidly removing it to outflows. The Non-Statutory Standards for SuDS (DEFRA 2015a) presented a requirement for all developments to integrate SuDS in their design to reduce runoff. This research models the impact on water quantity of combining different SuDS devices to demonstrate their success as a flood management system, as compared to conventional pipe based drainage. The research uses MicroDrainage®, the UK industry standard flood modelling tool which has an integrated SuDS function, to simulate the role of SuDS in a management train. As space is often cited as the primary reason for rejecting SuDS, determining the most effective technique at reducing runoff is critical. Detention basins were concluded as being highly effective at reducing peak flow (150 l/s when combined with swales), however Porous Pavement Systems (PPS) was nearly twice as effective per m3, reducing peak flow by up to 0.075 l/s/m3 compared to 0.025 l/s/m3. This therefore suggests that both detention basins and PPS should be high priority devices when developing new sites, but that no matter what combination of modelled SuDS are installed a reduction in runoff in comparison to conventional drainage can be achieved. A SuDS decision support tool was developed to assist design in MicroDrainage® by reducing the time spent determining the number of SuDS required for a site. The tool uses outputs from MicroDrainage® to rapidly predict the minimum and maximum peak flow for a site, in comparison to greenfield runoff, based on the site parameters of area, rainfall rate, infiltration, combined with the planned SuDS. The tool was underpinned by a model analysis for each site parameter and each SuDS device, which produced r2 values >0.8, with 70% above 0.9. This ensured a high level of confidence in the outputs, enabling a regression analysis between runoff and each site parameter and SuDS device at the 99% confidence level, with the outputs combined to create the tool. The final aspect of the research validated MicroDrainage® to analyse the accuracy of the software at predicting runoff. Using field data from Hamilton, Leicester, and laboratory data for PPS and filter drains, a comparison could be made with the output from MicroDrainage®. The field data created a Nash-Sutcliffe Efficiency (NSE) of 0.88, with filter drains and PPS providing an NSE of 0.98 and 0.94 respectively. This demonstrates the success with which MicroDrainage® predicts runoff and provides credibility to the outputs of the research. Furthermore, it offers SuDS specialists the confidence to use MicroDrainage® to predict runoff when using SuDS.

Master of Science / Department of Geology / Matthew Brueseke / It is generally accepted that beneath flood basalt provinces, Cu-Ni-PGE sulfide deposits may be found (Ridley, 2013). The focus of this study is the Steens Basalt, a mid-Miocene flood basalt from the northern Great Basin (USA) which contains between ~5-400 ppm copper and is characterized by large plagioclase phenocrysts, some of which can contain primary inclusions of copper despite the chalcophile nature of Cu (Hofmeister and Rossman, 1985; Johnston et al., 1991). The purpose of this project is to identify the distribution of Cu among coexisting phases in Steens Basalt, test whether plagioclase crystals in Steens lavas can host Cu, even when Cu is not visible, and test whether sulfide minerals/droplets are present in Steens Basalt samples with low Cu concentrations. Samples of Steens lavas were examined for sulfide minerals via reflected light microscopy, Raman spectroscopy, and X-ray diffraction with a molybdenum tube. Using an electron microprobe, silicate minerals, oxides, glass, and sulfides were analyzed for their Cu concentration, as well as other major and trace element chemistry. Glass did not contain detectable Cu which precluded partition coefficient (Kd) calculations. Based on average Cu concentration for the non-sulfides, magnetite contains the most Cu, followed by (forsteritic) weathered olivine, pyroxene, olivine, plagioclase, and ilmenite. Copper sulfides were discovered in samples MB97-19 and MB97-76C with additional non-copper sulfides in MB97-76B. In conclusion, these results lay the groundwork for further investigation into potential copper sulfide reserves in the magma plumbing as with other flood basalt packages linked to economically important mineral deposits.

<p>Doktorska disertacija razrađuje metodologiju izrade modela upravljanja poplavama na velikim ravničarskim rekama korišćenjem preciznih digitalnih modela terena (DTM) i kombinacije 1D/2D hidrauličkih modela nestacionarnog tečenja. Za razradu modela korišćena je reka Dunav na teritoriji Srbije sa svojim pritokama. Dužina hidrauličkog modela je 715 km i postignuta tačnost modela, poređenjem izračunatih i izmerenih nivoa na devet vodomernih stanica, je ispod 10 cm. Dosadašnja strategija odbrane od poplava na velikim rekama, kao što je Dunav, bazirala se na &quot;pasivnim merama&quot; izgradnje nasipa i kejskih zidova. U radu je prikazana mogućnost primene nove strategije upravljanjem poplavnog talasa preko uređenih retenzija. Rezultati disertacije su omogućili i rekonstrukciju poplavnog talasa iz 1965. g.</p> / <p>The dissertation elaborates a methodology for flood management model on<br />large lowland rivers using precision digital terrain models (DTM) and<br />combined 1D/2D unsteady flow model. For the development of the model,<br />the river Danube on the territory of Serbia was used with its tributaries. The<br />length of the hydraulic model is 715 km and the achieved accuracy of the<br />model, by comparing the calculated and observed levels on 10 water<br />stations, is below 10 cm. Оur current defense against floods in big lowland<br />rivers is relied on passive defence with building and overhanging existing<br />levees and walls. In dissertation is shown the possibility of applying a new<br />strategies of flood management with retentions. The results of the<br />dissertation also enabled the reconstruction of the 1965. flood wave.</p>

The central United States is a region of the country plagued by frequent catastrophic flooding (e.g., flood events of 1993, 2008, 2011, 2013, and 2014). In the twentieth and twenty-first centuries, flooding has taken a devastating societal and economic toll on the central United States, contributing to dozens of fatalities and causing billions of dollars in damage. Moreover, previous studies have shown that flood damage has been increasing over the past century across this region, and seems to foreshadow a future increase in flood activity. Despite these large repercussions, the use of historical records to ascertain the changes over time in flooding has thus far proved inconclusive. It is therefore of paramount importance to examine whether the characters (i.e., magnitude and frequency) of recent flooding are different from the long-term averages over the central United States. The results of this thesis are based on long-term discharge records at 774 U.S. Geological Survey sites and show limited evidence suggesting increasing or decreasing trends in the magnitude of flood peaks over the study region. In contrast, there is much stronger evidence of increasing frequency of flood events. While the detection of changes in flood characteristics is essential, it is also of critical importance to start exploring what caused these changes. Therefore, in addition to the aforementioned investigation on the stream flow records, precipitation records were used to inspect whether possible changes in flood characteristics can be linked to the changes in heavy precipitation characteristics. The results indicate that there is a stronger signal of change in the frequency rather than in the magnitude of heavy precipitation events, similar to what found for the discharge records. Given that heavy precipitation is responsible for the observed changes in flooding, further analyses were performed to examine the climatic driving forces that are responsible for the observed changes in the frequency of precipitation, and consequently flooding at the seasonal scale; particular emphasis was paid to the role played by the Atlantic and Pacific Oceans. The results of this dissertation indicate that changes in the climate system play a significant role in explaining the variations in the frequency of heavy precipitation and flooding over the central United States at both the seasonal and sub-seasonal scales. The Pacific North American (PNA) teleconnection pattern was found to play a particularly prominent role. Therefore, these results suggest that recent observed changes in the frequency of flood events over the central United States can be largely attributed to changes in the frequency of heavy precipitation events, which were in turn driven by changes in the climate system.

Modeling the movement of flood waters can be accomplished using many different methods with varying degrees of physical detail. Numerical models utilizing simple routing methods or simplified versions of the Navier-Stokes equations can be used to improve the public's flood preparedness. Three numerical models are used in this thesis to investigate flood preparedness: (1) an existing HEC-ResSim model of Coralville Reservoir, (2) an existing one-dimensional HEC-RAS model of the Iowa River through Coralville and Iowa City, and (3) a coupled one/two-dimensional hydraulic MIKE Flood model of the Cedar River through Cedar Falls/Waterloo. The HEC-ResSim model of Coralville Reservoir, provided by the United States Army Corps of Engineers, requires reservoir elevation-storage curves, inflow hydrographs and user-defined operation rules. This model utilizes level pool routing to determine changes in reservoir water levels and attenuation of hydrographs. The Muskingum routing method is used to route controlled releases downstream and determine satisfaction of constraints. The model is used to determine the impact of operational changes and sedimentation effects on historic flood events. Simulations indicate sedimentation has no effect on peak discharges of extreme events, but more aggressive operations plans may provide additional storage prior to extreme events. The existing HEC-RAS of the Iowa River through Iowa City is used to develop a library of inundation maps to be hosted on the National Weather Service Advanced Hydrologic Prediction Service's river forecast website. The modeling method assumes steady gradually varied flow. Post-processing and visualization of simulation results are completed using a digital elevation map of the study area developed using topography, bathymetry, and structural elevations. A coupled one/two-dimensional MIKE Flood model is developed for the Cedar River through Cedar Falls/Waterloo using topography, bathymetry, land use, and structural data. The river channel is modeled using MIKE 11, a one-dimensional unsteady hydraulic model, while the flood plain is modeled using MIKE 21, a two-dimensional hydraulic model utilizing depth-averaged Navier-Stokes equations. The model is used to develop a sequential levee closure plan for downtown Waterloo and will also be used to develop a library of inundation maps.

Numerical modeling of extreme flooding in an urban area in eastern Iowa is presented. Modeling is performed using SRH-2D, an unstructured grid, finite volume model that solves the depth-averaged shallow-water equations. Data from a photogrammetric stereo compilation, contour maps, a hydrographic survey and building records were used to create a digital elevation model depicting the river channel and floodplain. A spatially distributed Manning coefficient based on land cover classification, derived from aerial photography is also used. The model is calibrated with high-resolution inundation depth data derived from a 1 m light detection and ranging survey, collected during the falling limb of the flood hydrograph, and discrete global positioning system measurements of water surface elevation at a bankfull condition. The model is validated with discrete high water marks collected immediately after the flood event. Results show the model adequately represents the water surface elevation in the main channel and floodplain and that exclusion of the discharges from minor creeks did not affect simulation accuracy. Reach scale results are not affected by the presence of buildings, but local inconsistencies occur in shallow water if buildings are not removed from the mesh. An unsteady hydrograph approximates flood hydrodynamics better than a steady-state simulation, but extreme computation time is not feasible for most investigations. The two-dimensional model was also compared to a comparable one-dimensional model of the study reach. The 1D model suffered from an inability to accurately predict inundation depth throughout the entire study area.