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Floodplain Risk Analysis Using Flood Probability and Annual Exceedance Probability MapsSmemoe, Christopher M. 18 March 2004 (has links) (PDF)
This research presents two approaches to determining the effects of natural variability and model uncertainty on the extents of computed floodplain boundaries. The first approach represents the floodplain boundary as a spatial map of flood probabilities -- with values between 0 and 100%. Instead of representing the floodplain boundary at a certain recurrence interval as a single line, this approach creates a spatial map that shows the probability of flooding at each point in the floodplain. This flood probability map is a useful tool for visualizing the uncertainty of a floodplain boundary. However, engineers are still required to determine a single line showing the boundary of a floodplain for flood insurance and other floodplain studies. The second approach to determining the effects of uncertainty on a floodplain boundary computes the annual exceedance probability (AEP) at each point on the floodplain. This spatial map of AEP values represents the flood inundation probability for any point on the floodplain in any given year. One can determine the floodplain boundary at any recurrence interval from this AEP map. These floodplain boundaries include natural variability and model uncertainty inherent in the modeling process. The boundary at any recurrence interval from the AEP map gives a single, definite boundary that considers uncertainty. This research performed case studies using data from Leith Creek in North Carolina and the Virgin River in southern Utah. These case studies compared a flood probability map for a certain recurrence interval with an AEP map and demonstrated the consistency of the results from these two methods. Engineers and planners can use floodplain probability maps for viewing the uncertainty of a floodplain boundary at a certain recurrence interval. They can also use AEP maps for determining a single boundary for a certain recurrence interval that considers all the natural variability and model uncertainty inherent in the modeling process.
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Diseño de pavimento y sistema de drenaje pluvial del centro poblado de Ciudad de Dios, San José, Lambayeque, Lambayeque, 2021Acosta Guerrero, Ricardo Willy Octavio January 2023 (has links)
El objetivo general de este proyecto es mejorar el tránsito vehicular en el casco urbano de Ciudad de Dios, distrito de San José, mediante el diseño de pavimentos y drenaje de aguas pluviales. Las malas condiciones de las calles en el área estudiada conducen a pérdidas económicas debido a que no cuentan con pavimentación y una adecuada evacuación de aguas de lluvia. Vale señalar que los residentes locales sufren problemas respiratorios debido a los desechos transportados por el aire, ante las inundaciones previstas en los últimos años por El Niño y El Niño Costero.
A partir de los datos de la estación de Lambayeque, se está llevando a cabo una investigación hidrológica para establecer la precipitación máxima diaria. Para la modelización hidráulica se utilizó la versión 5.2 del SWMM (Modelo de Gestión de Aguas Pluviales de la Agencia de Protección del Medio Ambiente) de la EPA. Este es un software para la planificación de un drenaje pluvial urbano que puede diagnosticar e identificar la dirección de las aguas pluviales y obtener cálculos más precisos y optimizar el tiempo y costos.
El proyecto contará con una estructura de pavimento rígido y otra de drenaje hidráulico que admita evacuar las aguas en tiempos de lluvia. Al realizar este proyecto tal cual está planteado mejorará la calidad de vida de los residentes y promoverá el crecimiento. Por ende, se llevan a cabo la búsqueda de datos preliminares, la investigación básica, el análisis de resultados, la presentación final, la observación final y para el término la sustentación del proyecto la cual son procesos claves para la aceptación y desarrollo. / The overall objective of this project is to improve vehicular traffic in the urban area of Ciudad de Dios, district of San José, through pavement design and stormwater drainage. The poor condition of the streets in the study area leads to economic losses due to the lack of paving and adequate rainwater drainage. It is worth noting that local residents suffer from respiratory problems due to airborne debris in the face of the flooding predicted in recent years by El Niño
and El Niño Costero.
Based on data from the Lambayeque station, a hydrological investigation is being carried out to establish the maximum daily rainfall. For the hydraulic modeling, version 5.2 of the EPA's Stormwater Management Model SWMM (Stormwater Management Model of the Environmental Protection Agency) was used. This is an urban storm drainage planning software that can diagnose and identify the direction of stormwater, obtain more accurate calculations, and optimize time and costs.
The project will have a rigid pavement structure and a hydraulic drainage structure to evacuate water in times of rain. By realizing this project as planned, it will improve the quality of life of the residents and promote growth. Therefore, preliminary data research, basic research, analysis of the results, final presentation, final observation, and finally the project presentation are key processes for the acceptance and development of the project.
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A abordagem da geomorfologia antropogênica e de modelagens hidrológica e hidráulica na bacia do Córrego Três Pontes (SP) para determinação de picos de vazão e da vulnerabilidade a inundações / The anthropogenic geomorphology approach and hydrologicalhydraulic modelling applied in stream Três Pontes basin (São Paulo) to determine peak flow and flood vulnerabilityVeneziani, Yuri 27 June 2014 (has links)
Os atuais e persistentes cenários de enchentes da Região Metropolitana de São Paulo, e suas consequências em seu espaço e cotidiano, evidenciam a complexidade dessa problemática. A recorrência das enchentes sugere que, mesmo diante da adoção de medidas de controle, combate e mitigação, tais ações demonstraram-se insuficientes, estando associadas a limitações das metodologias e dos modelos a serem abordados. Este estudo relaciona-se a esta última proposição, testando e aplicando formas de integração das abordagens geomorfológicas, às abordagens oriundas da hidrologia e da hidráulica. O objetivo foi analisar as variabilidades temporal e espacial dos resultados de simulações hidrológicas e hidráulicas e compará-los aos mapeamentos obtidos pela Geomorfologia Antropogênica a partir da cartografia geomorfológica evolutiva na bacia hidrográfica do córrego Três Pontes (SP), de modo a identificar potenciais de complementariedade e integração dessas metodologias. Primeiramente, realizou-se a fotointerpretação e reconstituição das morfologias originais (1962) e das formas antropogênicas (2011), gerando cartografias de perturbação que assumiram diferentes graus de susceptibilidades às inundações e ao escoamento superficial concentrado. Em seguida, modelos hidrológicos (Ven Te Chow SCS e Hidrograma Unitário SCS, pelo ABC6) e hidráulico (pelo HECRAS) foram aplicados nos cenários reconstituídos anteriormente, determinando o aumento da vazão de pico e das áreas inundadas entre os anos estudados para tormentas de diferentes tempos de retornos. Os resultados das modelagens hidrológicas e hidráulicas demonstraram aumento significativo da vazão de pico e uma ampliação expressiva da área inundada na BHTP entre 1962 e 2011. Comparados os limites de áreas inundadas obtidos pela modelagem hidráulica à cartografia de vulnerabilidade à inundação, constatou-se uma compatibilidade de resultados. Por um lado, foram identificadas e discutidas limitações relacionadas aos pressupostos, parâmetros e coeficientes de ambas as metodologias; por outro lado, foram assinalados potenciais de integração entre elas. De modo geral, pode-se afirmar que os resultados obtidos contribuem ao conhecimento hidrológico e geomorfológico urbanos, em especial à área de estudo, e constitui um esforço interdisciplinar de aproximar duas especialidades fundamentais ao planejamento territorial urbano. / The current and persistent flooding scenarios in the Metropolitan Region of São Paulo, and their consequences on its space and life, point out to the complexity of this issue. The recurrence of flooding suggests that, even though policies of control, ordering and mitigation were adopted, its measures demonstrated not to be enough, associated with limitations of the methodologies and hydrological and hydraulic forecast models. This research is related to this last proposition, testing and applying ways in which the approaches of geomorphology, hydrology and hydraulics, can be integrated. Therefore, the study aims to analyze the temporal and spatial variability of hydrologic and hydraulic simulations results and to compare them with the mappings obtained by Anthropogenic Geomorphology from evolutionary geomorphological mapping at the stream Três Pontes basin, in order to identify the dialogues and potentials of integration between these methodologies. Firstly, airphotos and satellite images were interpreted and the original morphologies (1962) and anthropogenic forms (2011) reconstructed and mapped, from which disturbance maps were produced considering different susceptibilities to flooding and concentration of discharges. Afterwards, hydrological models (Ven Te Chow-SCS and Unit Hydrograph-SCS using ABC6 ) and hydraulic models (using HEC-RAS ) were applied considering the same scenarios previously reconstituted and, as a result, the increase on peak discharge and of flooding areas, between 1962 e 2011, were determined for different recurrence intervals. When compared, the boundaries of flooded areas obtained through the hydraulic modeling and the flood susceptibility cartography, demonstrated the compatibilities between the results. Limitations of some parameters, coefficients and assumptions related to both methodologies were identified and discussed, as well as, the potential of integration between the two. As a whole, the obtained results contribute to the urban hydrological and geomorphological knowledge, especially in the studied area, and constitute an interdisciplinary effort to approximate two fundamental territorial planning fields.
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A abordagem da geomorfologia antropogênica e de modelagens hidrológica e hidráulica na bacia do Córrego Três Pontes (SP) para determinação de picos de vazão e da vulnerabilidade a inundações / The anthropogenic geomorphology approach and hydrologicalhydraulic modelling applied in stream Três Pontes basin (São Paulo) to determine peak flow and flood vulnerabilityYuri Veneziani 27 June 2014 (has links)
Os atuais e persistentes cenários de enchentes da Região Metropolitana de São Paulo, e suas consequências em seu espaço e cotidiano, evidenciam a complexidade dessa problemática. A recorrência das enchentes sugere que, mesmo diante da adoção de medidas de controle, combate e mitigação, tais ações demonstraram-se insuficientes, estando associadas a limitações das metodologias e dos modelos a serem abordados. Este estudo relaciona-se a esta última proposição, testando e aplicando formas de integração das abordagens geomorfológicas, às abordagens oriundas da hidrologia e da hidráulica. O objetivo foi analisar as variabilidades temporal e espacial dos resultados de simulações hidrológicas e hidráulicas e compará-los aos mapeamentos obtidos pela Geomorfologia Antropogênica a partir da cartografia geomorfológica evolutiva na bacia hidrográfica do córrego Três Pontes (SP), de modo a identificar potenciais de complementariedade e integração dessas metodologias. Primeiramente, realizou-se a fotointerpretação e reconstituição das morfologias originais (1962) e das formas antropogênicas (2011), gerando cartografias de perturbação que assumiram diferentes graus de susceptibilidades às inundações e ao escoamento superficial concentrado. Em seguida, modelos hidrológicos (Ven Te Chow SCS e Hidrograma Unitário SCS, pelo ABC6) e hidráulico (pelo HECRAS) foram aplicados nos cenários reconstituídos anteriormente, determinando o aumento da vazão de pico e das áreas inundadas entre os anos estudados para tormentas de diferentes tempos de retornos. Os resultados das modelagens hidrológicas e hidráulicas demonstraram aumento significativo da vazão de pico e uma ampliação expressiva da área inundada na BHTP entre 1962 e 2011. Comparados os limites de áreas inundadas obtidos pela modelagem hidráulica à cartografia de vulnerabilidade à inundação, constatou-se uma compatibilidade de resultados. Por um lado, foram identificadas e discutidas limitações relacionadas aos pressupostos, parâmetros e coeficientes de ambas as metodologias; por outro lado, foram assinalados potenciais de integração entre elas. De modo geral, pode-se afirmar que os resultados obtidos contribuem ao conhecimento hidrológico e geomorfológico urbanos, em especial à área de estudo, e constitui um esforço interdisciplinar de aproximar duas especialidades fundamentais ao planejamento territorial urbano. / The current and persistent flooding scenarios in the Metropolitan Region of São Paulo, and their consequences on its space and life, point out to the complexity of this issue. The recurrence of flooding suggests that, even though policies of control, ordering and mitigation were adopted, its measures demonstrated not to be enough, associated with limitations of the methodologies and hydrological and hydraulic forecast models. This research is related to this last proposition, testing and applying ways in which the approaches of geomorphology, hydrology and hydraulics, can be integrated. Therefore, the study aims to analyze the temporal and spatial variability of hydrologic and hydraulic simulations results and to compare them with the mappings obtained by Anthropogenic Geomorphology from evolutionary geomorphological mapping at the stream Três Pontes basin, in order to identify the dialogues and potentials of integration between these methodologies. Firstly, airphotos and satellite images were interpreted and the original morphologies (1962) and anthropogenic forms (2011) reconstructed and mapped, from which disturbance maps were produced considering different susceptibilities to flooding and concentration of discharges. Afterwards, hydrological models (Ven Te Chow-SCS and Unit Hydrograph-SCS using ABC6 ) and hydraulic models (using HEC-RAS ) were applied considering the same scenarios previously reconstituted and, as a result, the increase on peak discharge and of flooding areas, between 1962 e 2011, were determined for different recurrence intervals. When compared, the boundaries of flooded areas obtained through the hydraulic modeling and the flood susceptibility cartography, demonstrated the compatibilities between the results. Limitations of some parameters, coefficients and assumptions related to both methodologies were identified and discussed, as well as, the potential of integration between the two. As a whole, the obtained results contribute to the urban hydrological and geomorphological knowledge, especially in the studied area, and constitute an interdisciplinary effort to approximate two fundamental territorial planning fields.
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Ecological impacts of in-stream restoration in salmonid rivers:the role of enhanced structural complexityKoljonen, S. (Saija) 01 November 2011 (has links)
Abstract
Despite the great amount of in-stream restorations conducted in the past decades there is still a disturbing lack of knowledge about the outcome of these measures. The overall goal of this study was to assess the effect of enhanced streambed heterogeneity on the ecology of stream salmonids and stream retention efficiency. Substratum heterogeneity is often considered as one of the most important limiting factors for organisms living in running waters.
Winter ecology of rivers has not been broadly studied regardless of the general belief that wintertime conditions strongly influence the survival and population size of stream salmonids. In an experimental study, the paucity of wintertime habitat in simplified channels caused temporary mass loss in age-0 trout. In late spring, channelized stream trout performed catch-up growth with potentially negative effects on long-term fitness. A management implication of this study is that increasing cover availability by in-stream restoration structures may enhance the long term success of juvenile salmonids although the short term effects were minor.
Densities of salmon parr in the River Kiiminkijoki showed no response to streambed restoration. Suitable habitat area for salmon parr increased after restoration under summer conditions. However, restoration-induced benefits to winter habitats were marginal, with one study reach indicating even negative values. Most of the areas with good habitat values were located along river margins, indicating that restoration measures had only limited impact on the mid-sections of the river channel.
Dredging of small streams may have caused depletion of allochthonous organic matter due to the reduction of retentive structures. In a leaf release experiment, moss cover enhanced retentiveness as well as did various restoration structures (boulders, large wood). Only a very high amount of wood clearly enhanced retention capacity. This underlines the importance of wood as an effective retention structure in headwater streams.
This study indicates that habitat complexity as such may be less important than life-stage specific habitat requirements of fish (e.g. cover for overwintering salmonids). Importantly, restoration may only be successful if the measures used target the limiting factor(s) of the ecosystem or the species; for salmonids, habitat complexity does not seem to be this factor. / Tiivistelmä
Uiton jälkeisten kunnostustoimenpiteiden määrä Suomessa on ollut huomattava, mutta vaikutusten arviointi, pelkästään kalastonkin kannalta, on jäänyt vähäiselle huomiolle. Tässä työssä selvitettiin kunnostusten merkitystä lohen ja taimenen poikasvaiheille, huomioiden etenkin pohjan rakenteellisen monimuotoisuuden vaikutus. Työssä selvitettiin myös kunnostusten vaikutuksia lehtikarikkeen pidätyskykyyn, joka on erityisesti latvapurojen ekosysteemien tärkeimpiä perustoimintoja.
Lohikalojen talviekologinen tutkimus on viime aikoihin saakka ollut vähäistä, vaikka talviolosuhteiden uskotaan rajoittavan pohjoisten virtavesien eliöstön elinmahdollisuuksia. Kokeellisessa työssä rännimäisissä uomissa talvehtiminen aiheutti taimenenpoikasille tilapäisen painon alenemisen ja nopean kompensaatiokasvun loppukeväällä. Kompensaatiokasvu voi vaikuttaa negatiivisesti koko kalan eliniän, joten kunnostusten tuoma hyöty sopivien suojapaikkojen lisääntymisenä voi edesauttaa lohikalojen pitkäaikaista menestymistä.
Kiiminkijoella lohenpoikasten tiheydet eivät muuttuneet kunnostuksen myötä ja vuosien välinen vaihtelu oli kuuden vuoden seurantajaksolla huomattavan suurta. Elinympäristömallinnuksen perusteella soveltuvan elinympäristön lisäys ei ollut merkittävää, koska etenkin talviaikaisten alueiden puute jäi huomattavaksi. Suurin osa soveltuvasta elinympäristöstä sijaitsi joen reuna-alueilla, joten kunnostusvaikutus joen keskiosaan jäi odotettua pienemmäksi.
Uittoperkaus on voinut johtaa latvavesien ekosysteemien köyhtymiseen maalta tulevan orgaanisen aineksen pidättymiskyvyn vähentyessä. Kokeellisen työn perusteella kuitenkin nykypäivän tilanne vuosikymmeniä uiton loppumisen jälkeen osoittautui lähes yhtä pidättäväksi kuin nykyisin käytetyt kunnostusrakenteet (kivi tai puu). Kunnostusrakenteeseen tulisi lisätä huomattava määrä puuta, jotta lehtikarike pidättyisi korkeallakin virtaamatasolla.
Tulosten perusteella elinympäristöjen muuttaminen monimuotoisemmiksi ei takaa kunnostustoimien onnistumista, sillä etenkin kalapopulaatioita rajoittavat yleensä useat tekijät. Jos kuitenkin elinympäristö on populaatiota rajoittava resurssi ja sitä pystytään lisäämään (kuten talviaikaiset suojapaikat), voidaan kunnostuksella saada näkyviä tuloksia. On ilmeistä, että kunnostustoimien tulisi olla nykyistä kattavampia ja paremmin suunnattuja rajoittaviin tekijöihin, jotta tulokset näkyisivät.
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Återskapande av naturliga trösklar i mindre vattendrag och våtmarker : Modellutveckling för simulering av förändradeflödesregimer / Recreation of natural thresholds in small rivers and wetlands : model development for the simulation of changing water flowsCronander, Joel January 2017 (has links)
Sveriges markanvändning ser idag annorlunda ut än för 100 år sedan. Det senaste århundradet har våtmarker dikats för att öka mängden odlingsbar areal. I och med utdikning av våtmarker förändrades den kustnära miljön, där många fiskarter har sina lekområden.När en minskning av predatorfisk observerades i Östersjöns kustnära områden i slutet av 1900-talet ansågs att exploatering av fiskens lekområden kunde vara en möjlig orsak för minskningen. För att återskapa naturliga lek- och uppväxtområden diskuteras nu en implementering av naturliga trösklar i diken som avvattnar kustnära våtmarker. I samband med dessa restaureringsarbeten utfärdar man beslutsprocesser tillsammans med bland annat markägare. För att kunna uppskatta och kvantifiera hur närområdet påverkas av en naturlig tröskel behöver effekten av den tilltänkta tröskeln på vattenflöden modelleras.I denna studie har därför en hydraulisk modell utvecklats för att kunna simulera vattenflöden i tre våtmarker som ligger på Öland där implementeringen av naturliga trösklar är tilltänkt: Maren, Hyllekärr och Brokhål. Modellen användes framförallt för att kunna uppskatta hur våtmarkerna översvämmas vid olika vattenföring. Genom ett observerat starkt samband mellan avrinningsområdets yta och vattenföring kunde extrema flödesscenarion simuleras. En metod för att beskriva naturliga trösklars påverkan på uppströms flödesregimer har utvecklats med hydraulisk modellering i HEC-RAS. För att validera modellresultaten uppmättes vattenflöde under vårflod 2017.Modellsimuleringen visade att endast Brokhål visade förväntade resultat, Maren visade förväntade resultat vid högre flöden och Hyllekärr visade orimliga översvämningar. Validering av resultaten visade att höjdmodellen som använts har visat felaktig topografisk information för alla tre våtmarkerna. Avvikelser och felaktigheter i topografi och batymetri har pekats ut som den största bakomliggande felkällan till modellen.Studien visade att naturliga trösklar har ingen, eller extremt liten påverkan på uppströms flödesregimer. Det bör dock poängteras att modellen har kraftiga begränsningar, särskilt höjdmodellens upplösning. Fler försök med modellen samt utveckling av höjdmodellen rekommenderas och resultaten från denna studie bör endast ses som vägledande. / In the late 20th century a decrease in coastal predatory fish in the Baltic Sea has been observed. It has been suggested that exploitation of the fish’s spawning habitats, mainly through draining of coastal wetlands, was one reason for the fish decline. To recreate spawn and growth areas, natural thresholds can be installed in trenches draining coastal wetlands. To quantify the effects of a natural threshold on water discharge in the drainage area under various water flow regimes modeling is needed.In this study, a hydraulic model was developed to estimate the effect of changing water discharges of three wetlands when natural thresholds are implemented, i.e. Maren, Hyllekärr and Brokhål, located on northern Öland. The model was run under different water flow regimes. Through an observed strong relation between catchment area and discharge, extreme discharge situations could be simulated. A method for investigating the effects of natural thresholds on upstream flow regimes has been developed with hydraulic modeling in HEC-RAS. To validate the model results, a comparison with empirical data during the spring flood 2017 was made.Model simulations showed that only water discharges in Brokhål behaved as expected, Maren behaved as expected for large flows and results for Hyllekärr were considered not being reliable. Validation showed that the elevation model for topography and bathymetry deviated from reality in all three wetlands. The elevation model has been identified as the single largest source of error in the water discharge model.From the model results, it is concluded that natural thresholds have none, or very minor effects on the upstream water flow regimes. It should however be emphasized that the model has major limitations, in particular the elevation model’s resolution. It is highly recommended to further develop the elevation model before further simulations on water discharges are made. The results from this study should only be considered as a first approximation where more detailed studies are needed to confirm that natural thresholds won’t result in major changes in upstream water flows.
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Modelamiento hidráulico para el control y prevención de inundaciones mediante el uso de Hec-Ras 2d en la zona urbana del río Piura / Hydraulic modeling for flood control and prevention using hec-ras 2d in the urban area of the piura riverAlvarez Montero, Gabriela Fiamma, Moreno Cueva, Carlos Alvaro 15 July 2021 (has links)
Los desastres ocasionados por las inundaciones son cada vez más comunes alrededor del mundo, tal como ocurre en la parte Occidental de América del Norte y Sur, debido a la presencia del Fenómeno “El Niño” (FEN), que provoca un aumento de las precipitaciones y caudales de los ríos provocando inundaciones. Por este motivo, en el presente trabajo se ha realizado la simulación numérica de inundación frente a eventos extremos como El Niño, con la finalidad de disminuir el área y nivel de inundación ante probables y distintos eventos en zonas cercanas a los cauces de ríos. Se ha empleado datos hidrológicos de caudales promedios y máximos instantáneos de un periodo de 40 años.
Para la caracterización morfológica de la zona se ha empleado información de un modelo de elevación digital del terreno (DEM), obtenido del satélite SPOT-7, de resolución de 6x6m. La información hidrológica fue procesada mediante el método de Gumbel para obtener los caudales de simulación para periodos de retorno de 2, 5, 10, 50, 100 y 500 años. La modelación numérica fue realizada empleando HEC-RAS 5.0.7, con lo que se obtuvo el área de inundación para el FEN 2017 y se utilizó la imagen satelital SENTINEL-2 para validar el modelo.
Asimismo, se modeló eventos extremos con periodos de retorno mayores a 10 años, ya que sus resultados son relevantes para la implementación de obras de protección ribereñas, en lugares estratégicos identificados por su mayor vulnerabilidad. Finalmente, dichas obras lograron mitigar el impacto generado al disminuir en un porcentaje el área inundada en la zona de estudio, desde la represa “Los Ejidos” hasta el puente Bolognesi en la provincia de Piura. / Disasters caused by floods are increasingly common around the world, such as the case in the western part of North and South America, due to the presence of the “El Niño” phenomenon, which causes an increase in rainfall and flow rates. The rivers causing floods. For this reason, this present work has carried a numerical simulation of flooding in the face of extreme events such as El Niño, with the purpose of reducing the area and level of flooding before probable and different events in areas close to riverbeds. Hydrological data of average flows and instantaneous maximums over a period of 40 years has been used.
For the morphological characterization of the area, information has been used on a digital terrain elevation model (DEM), obtained from the SPOT-7 satellite, with a resolution of 6x6m. The hydrological in-formation was processed using the Gumbel method to obtain simulation flows for return periods of 2, 5, 10, 50, 100 and 500 years. The numerical modeling was carried out using HEC-RAS 5.0.7, the flood area for FEN 2017 was obtained and compared with the SENTINEL-2 satellite image for validation.
Likewise, extreme events were modeled with return periods greater than 10 years, since their results are relevant for the implementation of riverine protection structures, in strategic locations identified with greater vulnerability. Finally, these works managed to mitigate impact showing reduction in a percentage of the flooding area in the study area, from “Los Ejidos” dam to Bolognesi Bridge, in the province of Piura. / Tesis
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Kalibrace hydraulického modelu vodovodní sítě / Calibration of hydraulic model of water supply networkNáplavová, Eva January 2020 (has links)
This diploma thesis deals with calibration of hydraulic simulation models, especially with methods used for calibration and parameters that are modified during calibration. The literature review in the field of mathematical modeling, basic principles applied in hydraulic modeling and the current approach to calibration and data collection is done in theoretical part. In the practical part of the thesis, a hydraulic model of the group water supply system Horní Dunajovice is built and subsequently calibrated. The calibration is first performed manually for the normal operational status and then using a calibration software created for this purpose for a load case with high velocity.
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Tomographie hydraulique des milieux poreux hétérogènes à partir de traçage thermique : approches expérimentales / Hydraulic tomography of heterogeneous porous media using thermal tracing methods : experimental approachesDjibrilla Saley, Abdoulazizi 10 December 2018 (has links)
L'importance des enjeux liés à la qualité et à la connaissance de l'eau souterraine nécessite de caractériser le fonctionnement des nappes d’eaux souterraines. En hydrogéologie, les méthodes qui permettent de réaliser le modèle conceptuel d’un aquifère reposent généralement sur l’observation et la caractérisation du milieu, à partir notamment de la mise en place de forages et la réalisation de pompages d’essai. Cependant, ces méthodes présentent des limites pour caractériser la variabilité spatiale des aquifères hétérogènes. Dans cette thèse, nous nous sommes intéressés au développement d’approches expérimentales qui utilisent des informations issues de traçage thermique ou salin pour la caractérisation des paramètres hydrauliques des milieux hétérogènes poreux. Ce choix expérimental a été justifié 1) par les difficultés de prise en compte des hétérogénéités hydrauliques dans les milieux poreux naturels et 2) pour une meilleure compréhension des phénomènes mis en jeu en situation contrôlée. Dans les travaux réalisés, nous avons tout d’abord proposé d’utiliser des mesures thermiques ponctuelles, puis obtenues dans l'infrarouge thermique pour estimer les paramètres hydrauliques en milieux poreux hétérogènes. Cependant, les méthodes de traçage thermiques étant limitées dans les zones faiblement perméables, nous avons fait évoluer notre approche en la combinant avec une méthode géophysique (Potentiel Spontané). Cette méthode, sensible aux écoulements des fluides et aux processus thermoélectrique et électrochimique, nous a permis de collecter des données temporelles intéressantes pour surveiller des variations thermiques ou saline provoquées dans les milieux. Les mesures obtenues ont été par la suite utilisées dans des algorithmes d’inversion pour estimer les distributions spatiales des propriétés hydrauliques. Les résultats obtenus nous ont permis de montrer l’efficacité de ces approches pour la caractérisation des milieux hétérogènes et par conséquent pour la modélisation des écoulements des fluides dans ces milieux. / The importance of issues related to the quality of groundwater requires characterizing the operation of groundwater aquifers. Hydrogeological methods used to carry out conceptual model of an aquifer are generally based on the observation and characterization of the medium, by using boreholes and carrying out of pumping test operations. However, these methods present some limitations in characterizing the spatial variability of heterogeneous aquifers. In this thesis, we develop experimental approaches that use information from thermal or saline tracing for the characterization of hydraulic parameters in heterogeneous porous media. The choice of using experimental approaches was justified 1) by difficulties of taking into account hydraulic heterogeneities in natural porous media and 2) for a better understanding of the phenomena involved in a controlled situation. In this work, we first proposed the use of punctual thermal measurements, then measurements obtained by using thermal infrared to estimate hydraulic parameters in heterogeneous porous media. However, as thermal tracing methods are limited in low permeability areas, we improved our approach by combining it with a geophysical method (Spontaneous Potential). This method, sensitive to fluid flows and thermoelectric and electrochemical processes, has allowed us to collect interesting temporal data to monitor thermal or saline variations in the media. The measurements obtained were then used in inversion algorithms to estimate the spatial distributions of hydraulic properties. The results obtained allowed to demonstrate the effectiveness of these approaches for the characterization of heterogeneous media and consequently for the modelling of fluid flows.
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Analysis of the Resilience of Intermittent Water Supply Systems and the Disruption-Dynamics of StakeholdersSaad I Aljadhai (9029648) 27 June 2020 (has links)
<p>Millions of households around the world rely on intermittent water supply systems (IWS), where piped water supply is limited to specific hours during the day or on specific days during the week. Households relying on IWS systems, as their primary water source, often adapt to supply intermittency by installing in-house water storage and/or supplying water from non-piped sources (for instance, in the form of water tanker trucks). The piped water distribution network (WDN) in IWS systems is subject to short-term disruptions that cause dynamic behavior and interactions of the system’s stakeholders, including households, vendors of non-piped water, and the water utility. During disruptions of the WDN, households make decisions about obtaining water from different non-piped sources at different prices and wait times. These decisions, made by a large number of households, have an impact on the dynamics (in particular, the prices and availability) of the non-piped water market, which may in turn affect each household decision. Prior studies on the literature of the analysis of IWS systems focused on analyzing each of the components (namely the WDN, households, vendors of non-pied water, and the water utility) of the IWS in isolation, assuming static behavior of the other components.</p><p>The overreaching objective of this dissertation is to bridge the gap in knowledge and practice in analyzing the short-term dynamics within each component of the IWS system (focusing on the WDN and the households) and the interactions among all components of the IWS system when responding to physical disruptions of the WDN. First, a new framework for quantifying and analyzing the resilience of intermittent WDNs is presented. The framework incorporates the aspects of intermittent supply (including household storage and supply scheduling) into a hydraulic model that examines the network’s hydraulic performance and its topology to assess three resilience capacities: absorptive, adaptive, and restorative, against various types of physical disruptive events. The evaluation of the model, using the IWS network of a case study city in the Middle East, shows that household storage capacities, timing and length of the disruption, supply inequity, and the supply scheduling are significant factors in determining the resilience of the WDN, and the interactions of these variables result in different combinations of direct and post effects on households. The framework was also used to evaluate the impact of temporary modifications of the supply schedule on the network’s resilience. The results show that this short-term utility adaptive measure can significantly improve the resilience of the network. The proposed framework can assist utilities in the operation of the intermittent WDN under normal conditions and in the evaluation of the impact of different short- and long-term resilience enhancement strategies.</p><p>Next, based on empirical data from a survey of households in a city in the Middle East, the households’ decision-making in response to disruptions of the WDN was evaluated using econometric methods. A set of Binary Probit models were developed to model the decision of households regarding their risk attitudes toward running out of water (represented by the timing of their response actions), their willingness to pay for faster delivery of non-piped water, and their willingness to wait in-line to obtain water from a non-piped source. The results show how variables related to household characteristics, wealth, age and occupation of the household’s manager, knowledge of household manager about their households’ water situation, and prior experience with disruptions affect the households’ decisions when the piped-network is disrupted. The outputs of the econometric models can assist the city’s water managers in understanding the behavior of households that affect the demand and prices of different non-piped water sources.</p><p>The final component in this research integrates the two previous components into an Agent-Based Model (ABM) to evaluate the dynamics of the stakeholders’ interactions in response to disruptions of the WDN and to evaluate the impact of these interactions on the resilience of the whole system. The ABM examines the interactions between households and vendors of water tankers under utility’s policies that regulate the water tanker market while integrating variables that describe the response of the WDN to the disruption. The demonstration of the model using a representative subset of the IWS system in the case study city shows dynamic behavior patterns in: (a) the dynamics of households, and (b) the performance of the non-piped water market under different deterministic and stochastic scenarios of disruptions of the WDN.</p><p>The results of this research address many IWS systems in the Middle East and around the world that are characterized by household storage, as well as households’ dependency on the piped network as the main water supply. The models developed in this dissertation are expandable to adopt various systems’ configurations in terms of types and capacities of household storage, types and attributes of non-piped water sources, and attributes and preferences of households. The results of this doctoral research can assist water managers in cities in understanding the behavior of their IWS system (including the WDN and the system’s stakeholders), evaluating long-term resilience enhancement policies, and planning for short-term response to disruptions of the WDN.</p>
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