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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Řešení protipovodňové ochrany obcí / Flood protection of municipalities

JÍLKOVÁ, Kateřina January 2017 (has links)
The thesis is focused on the issue of floods and the different types of flood protection measures that help to reduce human and material losses during floods. The thesis is divided into theoretical part where the basic concepts and possible solutions to flood control measures in the countryside and in the municipalities are defined. In the practical part there are described and assessed the examples of the flood protection measures in the selected locations. Individual measures are evaluated and compared with other flood control measures in different areas. The thesis also contains photographs depicting the true state of individual flood control measures in the area concerned, where some photographs show these measures also during floods.
232

Optimization/Simulation Model for Determining Real-Time Optimal Operation of River-Reservoirs Systems during Flooding Conditions

January 2015 (has links)
abstract: A model is presented for real-time, river-reservoir operation systems. It epitomizes forward-thinking and efficient approaches to reservoir operations during flooding events. The optimization/simulation includes five major components. The components are a mix of hydrologic and hydraulic modeling, short-term rainfall forecasting, and optimization and reservoir operation models. The optimization/simulation model is designed for ultimate accessibility and efficiency. The optimization model uses the meta-heuristic approach, which has the capability to simultaneously search for multiple optimal solutions. The dynamics of the river are simulated by applying an unsteady flow-routing method. The rainfall-runoff simulation uses the National Weather Service NexRad gridded rainfall data, since it provides critical information regarding real storm events. The short-term rainfall-forecasting model utilizes a stochastic method. The reservoir-operation is simulated by a mass-balance approach. The optimization/simulation model offers more possible optimal solutions by using the Genetic Algorithm approach as opposed to traditional gradient methods that can only compute one optimal solution at a time. The optimization/simulation was developed for the 2010 flood event that occurred in the Cumberland River basin in Nashville, Tennessee. It revealed that the reservoir upstream of Nashville was more contained and that an optimal gate release schedule could have significantly decreased the floodwater levels in downtown Nashville. The model is for demonstrative purposes only but is perfectly suitable for real-world application. / Dissertation/Thesis / Doctoral Dissertation Civil Engineering 2015
233

Natural Flood Management applications (NFM) : the role of local institutions

Ripiye, Ndenyangnde January 2016 (has links)
Natural Flood Management (NFM) is promoted as part of sustainable flood management (SFM) in response to climate change adaptation. Stakeholder engagement is central to this approach, and current trends are progressively moving towards a collaborative learning approach where stakeholder participation is perceived as one of the indicators of sustainable development. Within this methodology, participation embraces a diversity of knowledge and values underpinned by a philosophy of empowerment, equity, trust and learning. To identify barriers to NFM uptake, there is a need for a new understanding on how stakeholder participation could be enhanced to benefit individual and community resilience within SFM. This is crucial in the light of climate change threats and scientific reliability concerns. In contributing to this new understanding, this research evaluated eight (8) UK NFM case studies towards improving understanding of opportunities in involving communities in catchment-based working. An NFM strategy for participatory planning was developed from literature, findings from the UK studies and refined through a scenario development for a case study application in Taraba state, Nigeria using the constructivist model. Stakeholder and inter-agency collaboration for flood management in Taraba were investigated through interview methodology: 8 governmental agencies and 32 community leaders in Potentially Vulnerable Areas (PVA’s) of the state. Findings show some institutional weaknesses, which are seen to inhibit the development of adequate, flood management solution locally with damaging implications for vulnerable communities. The existences of weak institutional structures with poor coordination of the lead agency to effect change are identified as problematic within this context. Findings highlight a dominate top-bottom approach to management with very minimal public interactions. Current approaches are remedial with less emphasis on prevention and mitigation. The targeted approach suggested by the constructivist risk model is set against adaptive flood management and community development. The finding of the study suggests different agencies have different perspectives for “community participation”. It also shows communities in the case study area appear to be least influential, denied a real chance of discussing their situations and influencing the decision. This is against the background that the communities are located in the most productive regions, contributing massively to national food supplies. Stakeholder engagement and resilience planning underpin this research. The study explores dimensions of participation using the self-reliance and self –help approach to develop a methodology that facilitates reflections of currently institutionalised practices and the need to reshape spaces of interactions to enable empowered and meaningful participation. The results are discussed concerning practical implications for addressing interagency partnerships and conducting grassroots collaborations that empower local communities and seek solutions to development challenges.
234

Enhancing situational awareness and communication during flood crisis events using social media framework : the case of Bosnia and Herzegovina

Matar, Šadi Abdul Wahab January 2017 (has links)
The current thesis approaches the issue of using social media for the case of Bosnia and Herzegovina for the recurring flood crisis events. The current status of using and interacting with social media , through studying the literature of the previous facts and results towards using social media by governmental and public representatives have been investigated. Different experiences were found related to countries that are experiencing flood events and their uses of social media. On the other hand it was found that little or no information were presented for the uses of social media for crises events in Bosnia and Herzegovina case. It was found that the reasons for not having current implementation of a solution is related to the complex governmental structure that are present in the Bosnian state government, entities of Bosnia and Herzegovina, Brčko District, cantons and regions. Further investigations were initiated to identify the current uses, needs and obstacles towards the use of social media tools and services as a medium for increasing situational awareness and communication in Bosnia and Herzegovina. The considerations of the previous investigation were with respect to governmental complex structure and public needs. The results of the investigation managed to outline the current challenges with respect for each investigated sector. The outputs of the previous investigations have been used as inputs to direct and guide the system design of the proposed new system framework that is aiming for enhancing situational awareness and communication during flood crisis events using social media framework. The system design and functionalities have focused on providing sharing environment for the complex government structure and public needs with a direct focus on not distracting the current used structure and public ethnical segregations. The system framework has been tested and the reflection of governmental attitude and public results has been encouraging towards adopting this framework for future flood events in Bosnia and Herzegovina.
235

Non structural flood mitigation in Canada : linking the resources of today with a strategy for tomorrow

Slater, Alyson 05 1900 (has links)
Flooding poses one of the greatest natural hazard dangers to Canadians. As human populations increase and concentrate in areas vulnerable to floods, and uncertainty about future flood risk increases with the possibility of a changing climate, major urban communities, coastal settlements and communities located within floodplains are faced with an even greater risk of floods in the coming years. Canada's policies and practices towards flood control are best described as ad hoc, and have developed over the years in response to experiences with floods. No national scale flood damage reduction program exists, and there is currently no opportunity for Canadian homeowners to purchase flood insurance. This study specifically examines how a national mitigation strategy, focused mainly on non structural techniques could help decrease damages from floods in Canadian communities. The strategy proposed here is theoretically based in EPC and IBC suggestions for a greater national mitigation strategy, as well as IDNDR research, and federal, provincial and municipal goals for sustainable development and sound land use planning objectives. Ideally, a successful non structural flood mitigation strategy for Canada would address issues at the national scale, yet be implementable at the local level in accordance with community needs, risk characteristics, and local expertise. The strategy proposed here would maximize the efficiency of federal resources and private industry as well as allow local expertise and existing mitigation schemes to be formalized, bolstered and improved. There are three major components of the non structural flood mitigation strategy. Risk avoidance measures such as early warning systems, land use and resource planning and ecological conservation all work towards reducing the chances of a dangerous flood occurring. Risk spreading measures help communities deal with flood risks by improving equity and accountability, they include tax incentives, disaster financial assistance, and flood insurance. Lastly, vulnerability reduction measures help reduce damages if a flood were to strike, and these include enforcement of building codes and the maintenance of existing protective infrastructure. An integrated, non structural flood mitigation strategy would require basin-wide cooperation between all levels of government, citizens and the private sector. This strategy is also an opportunity for communities and individuals to meet goals of environmental conservation and sustainable development. The focus in this study lies on the mitigation tools, although it is the overall process of inserting the premise of mitigation into all land use and planning decision making processes that will be the key to successful flood mitigation strategies in Canadian communities. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate
236

Gestion supervisée de systèmes étendus à retards variables : cas des réseaux hydrographiques / Supervisory control of large scale system with varying time delay : hydrophical network case study

Nouasse, Houda 04 March 2015 (has links)
De part et d’autre de la Terre, on observe de plus en plus de phénomènes naturels dévastateurs, parmi lesquels les inondations constituent l’une des catastrophes les plus fréquentes. Ces dernières décennies d’importantes inondations ont été induites par les crues de rivières. Ces crues, dues à des pluies excessives ou aux eaux de ruissellement, causent sans cesse des pertes de vies humaines et des dégâts matériels importants. Pour remédier à ces problèmes, les réseaux hydrographiques sont de plus en plus équipés de moyens de détection de crues. Un facteur essentiel à la gestion de tels phénomènes est la réactivité. En effet, les gestionnaires des réseaux hydrographiques, dans ce genre de situation, doivent prendre rapidement des décisions importantes dans un contexte incertain, car la plupart de ces crues sont le fruit de phénomènes climatiques brusques, dont l’ampleur est difficile à évaluer avec précision. Nous proposons, dans ce mémoire, une méthode de gestion des crues dans des réseaux hydrographiques équipés de zones inondables contrôlées par des portes gravitationnelles. Dans un premier temps, nous avons modélisé notre méthode de gestion à l’aide d’un réseau de transport statique. Dans un second temps, nous l’avons enrichi en utilisant les réseaux de transport à retards dans le but de prendre en compte les temps de déplacement de la ressource gérée. Afin de pallier le problème de la taille importante des réseaux de transport à retards, nous avons élaboré un mécanisme de substitution combinant un réseau de transport statique réduit et une matrice de temporisation. De plus, ce mécanisme autorise la prise en compte des temps de transfert variables dépendant des débits, sans modification ni du réseau de transport, ni de la structure de la matrice de temporisation. Ce mécanisme permet donc une gestion simplifiée des temps de transferts, variables ou non. Avec ce mécanisme, l’évaluation du flot maximal à coût minimum, nous a permis, suivant les stratégies de gestion considérées, de consigner l’ouverture des portes des zones inondables afin d’écrêter la crue mais aussi afin de restituer cette eau stockée au moment opportun. Finalement, afin d’évaluer les apports de cette gestion, la méthode a été appliquée sur un cas d’étude basée sur un tronçon de rivière équipé de trois zones inondables et modélisé à l’aide de simulateurs hydrauliques combinant les approches de modélisation 1D et 2D. Les résultats de simulation obtenus ont montré que l’approche proposée permettait de réduire de manière significative les inondations en aval des cours d’eau. / On either side of the Earth, we observe more and more devastating natural phenomena. Amon these phenomena, floods are one of the most frequent and devastating natural disasters. During these last decades extensive flooding were caused by the flood of rivers. These floods due to excessive rainfall or runoff induce invariably the loss of human lives and material damages. To overcome these problems, water systems are increasingly equipped with means for detecting floods. A key factor in the management of such phenomena is responsiveness. Indeed, managers of river systems, faced to this kind of situation should quickly take important decisions in an uncertain context, as most of these floods are induced by abrupt climate events, whose magnitude is difficult to assess accuracy. We propose in this dissertation, a method of flood management in river systems equipped with flood zones controlled by gravitational gates. At first, we modeled our management method using a static transportation network. In a second step, we enriched it by using transportation networks with delays in order to take into account the travel time of the managed resource. The main difficulty of transportation networks with delays is their oversize. To overcome this problem, we developed an alternative mechanism combining a static reduced transportation network with a temporization matrix. Furthermore, this mechanism allows the consideration of variable time transfer depending on flows, without modification either on the transportation network, or on the structure of the temporization matrix. This mechanism allows simplified management of the transfer times, variable or not. With this mechanism, the evaluation of the minimum cost maximum flow allowed us, according to the management strategies considered, to compute the gate opening for floodplains in order to mitigate the flood but also to restore the water stored at the relevant time. Finally, to evaluate the contributions of this management, the method was applied to a case study based on a section of river equipped with three flood control reservoirs areas modeled using hydraulic simulators combining 1D and 2D models. The simulation results showed that the proposed approach allowed reducing significantly the floods downstream watercourses.
237

Návrh protipovodňové ochrany na vybrané části toku / Design of flood protection on selected location of the river

Filípková, Monika January 2019 (has links)
The master’s thesis deals with the hydraulic analysis of the water flow capacity for the flood flow on the river Litava in the river kilometres 11,550 – 18,315 using the HEC-RAS 5.0.5 specifically 1D-2D numerical model. On the basic of flood areas, depths and speeds the results were evaluated and subsequently was created own proposal flood protection.
238

Forecasting Inundation Extents in the Amazon Basin Using SRH-2D and HAND Based on the GEOGloWS ECMWF Streamflow Services

Edwards, Christopher Hyde 02 August 2021 (has links)
Floods are the most impactful natural disasters on earth, and reliable flood warning systems are critical for disaster preparation, mitigation, and response. The GEOGloWS ECMWF Streamflow Services (GESS) provide forecasted streamflow throughout the world. While forecasted discharge is essential to flood warning, forecasted inundation extents are required to understand and predict flood impact. In this research, I sought to expand GESS flood warning potential by generating inundation extents from streamflow forecasts. I compared Height Above Nearest Drainage (HAND), a method beneficial for flood mapping on a watershed scale, to a 2D hydrodynamic model, specifically Sedimentation and River Hydraulics – Two Dimension (SRH-2D), a method localized to specific areas of high importance. In three study areas in the Amazon basin, I validated HAND and SRH-2D flood maps against water maps derived from satellite SAR imagery. Specifically, I analyzed what features of an SRH-2D model were required to generate more accurate flood extents than HAND. I also analyzed the practicality of using SRH-2D for forecasting by comparing flood extents generated from simulating a complete forecast hydrograph to flood extents precomputed at predetermined, incremental flowrates. The SRH-2D models outperformed HAND, but their accuracy decreased at flowrates different than those used for calibration, limiting their reliability for forecasting and impact analysis. Based on this study, the key features necessary for a reliable SRH-2D model for forecasting include (1) a high-resolution DEM for an accurate representation of the floodplain, (2) correct representation of channel flow control, and (3) a channel bathymetry approximation and exit boundary rating curve that correctly predict water levels at a range of input flowrates. For forecasting practicality, the precomputed flood extents had accuracies comparable to the complete hydrograph simulations, showing their potential for estimating forecasted inundation extents. Future research should include (1) a more comprehensive analysis using existing SRH-2D models in areas with more bathymetry information and calibration data, (2) further assessment of the reliability of precomputed flood maps for forecasting applications, and (3) quantifying the effect of error in the streamflow forecasts on the accuracy of the resulting flood extents.
239

Hodnocení efektivnosti protipovodňových opatření v lokalitě Břeclav / Evaluation of flood protection measures effectiveness in the locality of Břeclav

Kozubík, Jiří January 2013 (has links)
Master´s thesis deals with the evaluation of the effectiveness and efficiency of the proposed flood protection measures in the affected area between the low Nové Mlýny reservoir and Pohansko weir at the Dyje river. The evaluation was done using the multicriteria decision analysis. The analysis was based on hydraulic calculations using 2D hydrodynamic model.
240

Studie proveditelnosti protipovodňových opatření / Feasibility study of the flood protection measures

Kacálek, Tomáš January 2014 (has links)
This diploma thesis deals with assessment of flood protection measures in Břeclav. Hydraulic calculations of proposal flood events were carried out using 2D numerical model of water flow. Several simulations took account of construction phases and different values of proposal discharge. The hydraulic calculations were computed for river Thaya including its relief branch. The results were processed in the form of inundation maps, depth maps and they were recorded in longitudinal profiles of rivers.

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