Dissertations / Theses on the topic 'Extreme floods in Bangladesh'
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1
Hofer, Thomas. "Floods in Bangladesh : a highland-lowland interactions ? /." Berne : University of Berne Institute of Geography, 1998. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Melone, Anthony Michael. "Extreme floods in the Pacific coastal region." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/27143.
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The research program developed hydrograph procedures for estimation of extreme rain-on-snow floods on ungauged watersheds in the Pacific coastal region. A multi-disciplinary investigation was undertaken encompassing the areas of hydrometeorology, snow hydrology and hydrologic modelling. Study components include assessment of flood producing mechanisms in the coastal region; analysis of regional rainfall characteristics for input to a hydrograph model; examination of the role of a snowpack during extreme events; and application of a hydrograph model.
Based on an assessment of atmospheric processes which affect climate, examination of historical flood data, and analysis of flood frequency, it is shown that the area bounded by the crests of the coastal mountains forms a hydrologic region with similar flood characteristics. Extreme floods in the coastal region are rainfall-induced, either as runoff from rainfall-only or as a combination of rain and snowmelt.
Recorded storm rainfall along the coast was examined to determine whether regional characteristics could be identified from available data even though the magnitude of rainfall varies between stations. Multi-storm intensity data available from Atmospheric Environment Service and rainfall intensities occurring within single storms that were identified as part of this study were analyzed. Results show that ratios of shorter duration intensities to the 24-hour rainfall are in a relatively narrow range in the coastal region for both multi and single storm intenstity data, and this range set limits on the hourly intensities that need to be considered as input rainfall data to a hydrograph model. With regard to basin response to extreme rain-on-snow, available literature suggests that for a ripe snowpack, development of an internal drainage network within the snowpack is the dominant routing mechanism for liquid water. Consequences of this conclusion on hydrograph procedures are that a watershed undergoes a transition from snow-controlled to more terrain-controlled water movement and basin storage characteristics approach conditions which would occur on the same basin without a snowcover.
Lag and route hydrograph techniques were investigated to assess whether this method can be applied to rain-on-snow floods. Results from analysis of two rain-on-snow floods suggest this procedure can be applied when the following methodology is adopted: 1) estimate travel time through the basin from channelized and overland flow considerations; 2) select a storage coefficient which simulates basin response; 3) take water inputs as the sum of snowmelt and rainfall; and 4) consider there are no losses to groundwater.
The combination of results from each study component provides a methodology for estimating input rainfall data and for undertaking hydrograph analysis for extreme rain-on-snow floods in the mountainous Pacific coastal region.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Khondaker, Mohammad S. "Perception of and response to floods in Bangladesh." Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277489.
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Cook, Brian Robert. "Knowledges, controversies and floods : national-scale flood management in Bangladesh." Thesis, Durham University, 2010. http://etheses.dur.ac.uk/371/.
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This research explores the views, beliefs and knowledges of experts responsible for flood management in Bangladesh. As one of the most disaster-prone nations on Earth, and in response to the neglect of power-holding experts within the existing literature, this project analyses the differences between academic accounts of flooding, labelled the ‘prevailing understanding’, and the local expertise of those responsible for management. Relative to the entrenched narrative, local experts are surveyed and an alternate interpretation is constructed using their knowledge. This combination of textual and perception-based analyses accounts for the complex interrelations between competing forms of knowing. It is on this juxtaposition that the research contributes to new knowledge. The thesis is based on research conducted in Bangladesh between November 2007 and March 2008. To accomplish its objectives, using prominent debates as entry points, academic and government sources are used to account for the lineage of the prevailing understanding. On the basis of this narrative, qualitative interviews with 54 experts explore the construction of flood management knowledge and its relationship with decision making. The experts describe and justify understandings of flood management that are contextual, adaptive and indefinite, challenging many of the assumptions associated with the prevailing understanding. The findings inform several findings: that individuals close to the poverty line are uniquely vulnerable; that disasters merge with management to produce second-generation events; and that a hybrid socio-physical context is both a product and a producer of flood management knowledge. Overall, despite the already complex issue of flooding, managers in Bangladesh consider increasingly issues as diverse as poverty, environmental sustainability and economic and human development. Given the scope of the controversy surrounding flood management, the findings show how analyses of competing knowledges, assumptions and framings can aid the interrogation of prevailing knowledge to generate original findings
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Stolle, Jacob. "Debris Hazard Assessment in Extreme Flooding Events." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39621.
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Coastal areas are often important to economic, social, and environmental processes throughout the world. With changing climate and growing populations in these areas, coastal communities have become increasingly vulnerable to extreme flooding events, such as tsunami, storm surges, and flash floods. Within this new paradigm, there has been an effort to improve upon current methods of hazard assessment, particularly for tsunami. Recently, the American Society of Civil Engineers (ASCE) released the ASCE 7 Chapter 6 which was the world’s first standard, written in mandatory language, that addressed tsunami resilient design in a probabilistic manner for several of its prescriptions. While often the focus tends to be on mapping the hazards related to hydraulic loading conditions, post-tsunami field surveys from disaster-stricken coastal communities have also shown the importance of also considering the loads exerted by solid objects entrained within the inundating flows, commonly referred to as debris loading. Limited research has addressed debris hazard assessment in a comprehensive manner.
Debris loading can be generally divided into two categories: impact and damming. Debris impact loads are caused by the rapid strike of solid objects against a structure. Debris damming loads are the result of the accumulation of debris at the face of or around a structure, causing thus an obstruction to the flow. The primary difference between these loads is the time period over which they act. The rapid loading due to debris impacts requires structural properties be considered in assessing the associated loads whereas debris damming loads are generally considered in a quasi-static manner. In assessing the hazard associated with both impact and damming loading conditions, methodologies must be developed to consider the likelihood of the load occurring and the magnitude of that load.
The primary objective of this thesis was to develop a probabilistic framework for assessing debris hazards in extreme coastal flooding events. To achieve this objective, the components of the framework were split into three general categories: debris transport, debris damming, and debris impact. Several physical experimental studies were performed to address each of these components, representing the most comprehensive assessment of debris hazards in extreme flooding events to date.
Debris transport was addressed to estimate the likelihood of debris loading occurring on a structure. The studies presented herein examine the different parameters that must be considered in assessing the motion of debris with the flow. The studies showed that the initial configuration of the debris and hydrodynamic conditions were critical in determining the motion of the debris. The stochastic properties of the debris motion were also assessed. It was shown that the lateral displacement of the debris could be approximated by a Gaussian distribution and the debris velocity by a Kumaraswamy (1980) distribution. The study of debris impact was further used to develop the current models used in estimating the impact force. The rigid body impact model was compared to models where the structural response was considered. The analysis showed that the effective stiffness model proposed by Haehnel and Daly (2004) was best suited to provide a conservative estimation of the impact force. Additionally, the impact geometry was taken into consideration examining the influence of various parameters on the impact force. Furthermore, debris damming was examined for the first time in transient loading conditions. This particular study examined the influence of the transient wave condition on the debris dam formation as well as the influence of different debris geometries. The influence of the debris dam geometry was correlated to increases in loading and overtopping conditions at structures. The assessment of debris hazards is critical in the development of accurate design conditions. The probabilistic framework presented within this thesis is expected to provide a basis for estimating debris hazards and inform future studies in the development of hazard assessment models.
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Jahan, Shafkat. "Assessment of flood-related mental illness in Bangladesh." Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/86511/8/Shafkat_Jahan_Thesis.pdf.
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This thesis assessed the mental health impacts of flooding and explored the key determinants of flood-related mental illness in the coastal region of Bangladesh. This study found significant increase in the prevalence of mental illness after flooding. Flood-exposure and socio-economic factors were significantly associated with post-flood mental illness. These findings may help the policy-makers to improve the early intervention and screening programs and may also have significant public health implications in the control and prevention of flood-related mental illness in Bangladesh.
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Eljabri, Sumaya Saleh M. "New statistical models for extreme values." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/new-statistical-models-for-extreme-values(12e1ec08-dc66-4f20-a7dc-c89be62421a0).html.
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Extreme value theory (EVT) has wide applicability in several areas like hydrology, engineering, science and finance. Across the world, we can see the disruptive effects of flooding, due to heavy rains or storms. Many countries in the world are suffering from natural disasters like heavy rains, storms, floods, and also higher temperatures leading to desertification. One of the best known extraordinary natural disasters is the 1931 Huang He flood, which led to around 4 millions deaths in China; these were a series of floods between Jul and Nov in 1931 in the Huang He river.Several publications are focused on how to find the best model for these events, and to predict the behaviour of these events. Normal, log-normal, Gumbel, Weibull, Pearson type, 4-parameter Kappa, Wakeby and GEV distributions are presented as statistical models for extreme events. However, GEV and GP distributions seem to be the most widely used models for extreme events. In spite of that, these models have been misused as models for extreme values in many areas.The aim of this dissertation is to create new modifications of univariate extreme value models.The modifications developed in this dissertation are divided into two parts: in the first part, we make generalisations of GEV and GP, referred to as the Kumaraswamy GEV and Kumaraswamy GP distributions. The major benefit of these models is their ability to fit the skewed data better than other models. The other idea in this study comes from Chen, which is presented in Proceedings of the International Conference on Computational Intelligence and Software Engineering, pp. 1-4. However, the cumulative and probability density functions for this distribution do not appear to be valid functions. The correction of this model is presented in chapter 6.The major problem in extreme event models is the ability of the model to fit tails of data. In chapter 7, the idea of the Chen model with the correction is combined with the GEV distribution to introduce a new model for extreme values referred to as new extreme value (NEV) distribution. It seems to be more flexible than the GEV distribution.
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Suyanto, Adhi. "Estimating the exceedance probabilities of extreme floods using stochastic storm transportation and rainfall - runoff modelling." Thesis, University of Newcastle Upon Tyne, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386794.
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Methods of estimating floods with return periods of up to one hundred years are reasonably well established, and in the main rely on extrapolation of historical flood data at the site of interest. However, extrapolating the tails of fitted probability distributions to higher return periods is very unreliable and cannot provide a satisfactory basis for extreme flood estimation. The probable maximum flood concept is an alternative approach, which is often used for critical cases such as the location of nuclear power plants, and is viewed as a consequence of a combination of a probable maximum precipitation with the worst possible prevailing catchment conditions. Return periods are not usually quoted although they are implicitly thought to be of the order of tens of thousand of years. There are many less critical situations which still justify greater flood protection than would be provided for an estimated one-hundred year flood. There is therefore a need for techniques which can be used to estimate floods with return periods of up to several thousand years. The predictive approach adopted here involves a combination of a probabilistic storm transposition technique with a physically-based distributed rainfall-runoff model. Extreme historical storms within a meteorologically homogeneous region are, conceptually, moved to the catchment of interest, and their return periods are estimated within a probabilistic framework. Known features of storms such as depth, duration, and perhaps approximate shape will, together with catchment characteristics, determine much of the runoff response. But there are other variables which also have an effect and these include the space-time distribution of rainfall within the storm, storm velocity and antecedent catchment conditions. The effects of all these variables on catchment response are explored.
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Islam, Md Faridul. "An investigation into the relationship between tourism development and extreme poverty alleviation in rural Bangladesh." Thesis, Curtin University, 2012. http://hdl.handle.net/20.500.11937/70465.
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This thesis contributes to the understanding of the relationship between tourism development and extreme poverty alleviation in rural Bangladesh. It adopts a critical theory approach to investigate the social, economic, physical, cultural and political barriers that exclude rural poor and indigenous communities from tourism development benefits. An integrated model proposes that these communities can be included in tourism development through gaining power, legitimacy and urgency as definitive stakeholders, thereby alleviating extreme poverty in developing countries.
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Kamwi, Innocent Silibelo. "Fitting extreme value distributions to the Zambezi river flood water levels recorded at Katima Mulilo in Namibia." Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&.
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The aim of this research project was to estimate parameters for the distribution of annual maximum flood levels for the Zambezi River at Katima Mulilo. The estimation of parameters was done by using the maximum likelihood method. The study aimed to explore data of the Zambezi's annual maximum flood heights at Katima Mulilo by means of fitting the Gumbel, Weibull and the generalized extreme value distributions and evaluated their goodness of fit.
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Wooten, Rebecca Dyanne. "Statistical environmental models : hurricanes, lightning, rainfall, floods, red tide and volcanoes." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001824.
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Cordero, Mera Andrea Estefania. "Reservoir influences on droughts and floods characteristics in the Piedmont Region, Italy." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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Among the consequences of global climate change, the alteration of hydrological cycles is one of the most worrisome, since it can result in an intensification of the characteristics of extreme events. In the Anthropocene era, human activities can further increase the frequency and magnitude of floods and droughts. Therefore, it is of utmost importance to analyse the influence of anthropogenic activities on the magnitude and frequency of hydrologic extremes. In the present work, Piedmont region (Italy) was taken as a case study. The work analyses 15 pairs of regulated up- and downstream catchments characterized by the presence of dam/reservoirs (hydroelectrical, irrigation and small artificial reservoirs). Following an analysis of the climate and hydrological regime of the catchments, based on the collection and spatial processing of hydro-meteorological time-series, a main general purpose has been assigned to each catchment and information on the reservoirs present in the basins were collected. Then, extreme events occurring in the last decades were identified using the threshold level approach with a constant and variable threshold for droughts, and the peak over threshold method for floods. The characteristics of the extreme events, such as duration, deficit/volume and intensity/peak were then computed. The quantification of the impact of the different dam/reservoir purpose was analysed through the paired-catchment analysis, which consists in the comparison of the drought/flood characteristics between up- and downstream catchments. The obtained results seem to indicate an overall alleviation of the severity of the drought and flood metrics downstream. It was also noticed that the magnitude of these changes is related to the dam/reservoir purpose (higher for hydroelectric purpose) and their volume. This study could be used as a first estimate of human influence (reservoirs) on hydrological extremes in Piedmont.
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Hossain, Md Zakir. "Pro-poor urban adaptation to climate change in Bangladesh : a study of urban extreme poverty, vulnerability and asset adaption." Thesis, Heriot-Watt University, 2014. http://hdl.handle.net/10399/2779.
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This dissertation investigates pro-poor urban adaptation to climate change in Bangladesh. Dhaka city, a capital of Bangladesh, is widely recognised to be one of the most climate vulnerable mega cities in the world. Climate change impacts are likely to affect the poorest urban residents disproportionately as having the least capacity to adapt to a changing climate. However, the assertion that the poorest are the most vulnerable to climate change is commonly made as a generalisation, with limited examination of the dynamic and differentiated nature of poverty. This research therefore aims to examine pro-poor urban adaptation in the context of climate variability and change. In analysing climate change vulnerability and asset adaptation from urban extreme poverty, this research identifies a differentiated view of poverty and vulnerability and also provides an analysis of how extreme poor households get access to assets and build asset adaptation strategies. This research found that extreme poor households do their best to adapt to perceived climate changes, but in absence of savings, access to credit and insurance, they are forced to adopt adverse coping strategies. Social policy and social protection could therefore become more of a priority sector for adaptation than it has been so far. This can create opportunities for the poorest to accumulate assets which help them to build asset adaptation or resilience strategies. By reviewing key theories and practices, this research first addresses the question of whether there is any interrelation between poverty dynamics and vulnerability. The research then explores drivers of climate change vulnerability for the urban extreme poor. This research critically analyses autonomous adaptation and planned asset based adaptation in order to build a conceptual framework of pro-poor asset adaptation for the urban extreme poor households and groups. Following this framework, this research aims to identify the individual adaptation practices and role of institutions and policies in supporting or constraining these adaptation practices. This research also examines the role of social policy and social protection for pro-poor adaptation. The research then applies the concepts drawn from a critical literature review to analyse the context of Bangladesh. Thus, the research has conducted household life-history interviews to explore the vulnerabilities and asset adaptation strategies of the extreme poor households. To understand household asset endowments (and their returns) descriptive statistics are derived from secondary sources. In addition to household interviews, key informant surveys, focus group discussions, grey materials and analysis of secondary academic materials were analysed to acquire qualitative information on the role of formal and informal institutions and policies for adaptation practices. The household life-history findings support the idea that poverty traps are likely to be linked to vulnerability. The empirical evidence also shows that there is a clear relationship between vulnerability to the market (exclusion from market opportunities), low asset holdings (and their returns) and ill-health. The slums and squatter settlements in Dhaka city are marked by high levels of physical vulnerabilities in the context of climate change, mainly as a consequence of their high politico-legal and socioeconomic vulnerabilities. The individual adaptation practices are impact-minimising, short lived, ad hoc and even harmful measures because the urban poorest are excluded from formal policies and institutions and in the absence of formal rights and entitlements, the process of facilitating and maintaining patron–client relationships is a central coping strategy for the poorest. The social policy and social protection are found to be effective in facilitating asset adaptation for the urban extreme poor and contribute to greater resilience to climate change. Analysing the empirical evidence through the lens of the pro-poor asset adaptation framework, this research reveals that the asset transfer approach was an effective programmatic intervention for building household adaptation strategies. Social funds and supports to community driven development can enhance the capacity of community organisations to develop small infrastructures that actually stops or greatly reduces flooding. However, challenging the adverse structural context is not a matter of building at a household and collective level assets but also capacity to participate in and influence the institutions from which they have previously been excluded. Attention must be paid to building a strong collective organisation in order to break the existing social order and inequalities. The city and municipal government can create an enabling environment for this grassroots mobilisation by providing services and information, and ensuring their access to the decision making process. A combination of micro (household), meso (community) and macro (city and municipal) level asset-based actions can ensure the long term resilience of extreme poor households and groups.
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Giampieri, Mario A. (Mario Andreś). "Vulnerability of What? Vulnerability of Whom? : evaluating and communicating vulnerability to extreme floods in Houston, TX using a novel web-based platform." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118071.
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Thesis: M.C.P., Massachusetts Institute of Technology, Department of Urban Studies and Planning, 2018.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 81-88).
The global climate is changing and these changes will continue to have adverse effects on cities and their residents. Coastal cities in particular, which contain the majority of the global urban population, are becoming increasingly sensitive to changing climactic conditions. The particularly devastating extreme storm season experienced in 2017-18 on the east coast of the United States (including storms Harvey, Irma, Maria, and four nor'easters on the mid-Atlantic coast) has intensified discussion regarding the preparation for, response to, and communication of risk and vulnerabilities related to extreme weather events. Risk is a function of the probability of experiencing a hazard event and the vulnerability of the system in question. Vulnerability to extreme weather events is the susceptibility of a system to internal or external stressors, exposure to those stressors, and the capacity of that system to adapt or respond to that extreme event. These concepts are understood in terms of social, economic, environmental, infrastructural, institutional, and built environment systems, and the focus of policymakers and stakeholders is often split between these domains. Furthermore, responses to vulnerability of any one categorical domain is potentially incongruous with responses to other domains. The modes by which this information is presented to decision-makers often either preferences single domains of interest or obscures the degree to which individual categories influence overall measures of vulnerability. Similarly, this information is often spatialized and presented in a planimetric view which is at times at odds with the conditions experienced on the ground before, during, and after an extreme event. This project begins with a review of relevant literature exploring definitions and measures of vulnerability to extreme flood events, identifying gaps in existing categorical domain combinations and opportunities for the application of a novel method of synthesis for Houston, Texas, a city hit by three 500-year storms in as many years and in the process of updating building codes, flood zone designations, and precipitation estimates. This method is then applied using established statistical tools to create vulnerability scores for social and built environment systems. The result of this analysis is presented in a novel way using web-based technologies that transcend the strictly-planimetric view of the city. This method blends traditional cartographic techniques with perspective, elevation, and diagrammatic representation methods, as well as collected images, to contextualize estimated vulnerability. The resultant web tool is available online at houstonbetweenthelines.com.
by Mario A. Giampieri.
M.C.P.
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De, Waal Jan Hofmeyr. "Extreme rainfall distributions : analysing change in the Western Cape." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71654.
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Thesis (MSc)--Stellenbosch University, 2012.Severe floods in the Western Cape have caused significant damage to hydraulic structures, roads and other infrastructure over the past decade. The current design criteria for these structures and flood return level calculations are based on the concept of stationarity, which assumes that natural systems vary within an envelope of variability that does not change with time. In the context of regional climate change and projected changes in rainfall intensity, the basis for these calculations may become unrealistic with the passage of time. Hydraulic structures and other infrastructure may become more vulnerable to damaging floods because of changing hydroclimatic conditions. This project assesses the changes in extreme rainfall values over time across the Western Cape, South Africa. Using a Generalised Pareto Distribution, this study examines the changes in return levels across the Western Cape region for the periods 1900-1954 and 1955-2010. Of the 137 rainfall stations used in this research, 85 (62%) showed an increase in 50-year return level, 30 (22%) a decrease in 50-year return level and 22 (16%) stations displayed little change in rainfall intensity over time. While there were no clear spatial patterns to the results, they clearly indicate an increase in frequency of intense rainfalls in the latter half of the 20th and early 21st century. The changes in return level are also accompanied by a change in the frequency of high intensity 2-3 day long storms. 115 (84%) of the 137 rainfall stations showed an increase in the frequency of long duration, high intensity storms over the data record. This change generates a shifting risk profile of extreme rainfalls, which, in turn, creates challenges for the design of hydraulic structures and any infrastructure exposed to the resulting damaging floods. It can therefore be argued that it is inappropriate to design structures or manage water resources assuming stationarity of climate and that these principles should be assessed in order to reduce the risk of flood damage owing to increasing storm intensity. KEY WORDS Flood Risk, Stationarity, Disaster Risk, Hazard, Extreme Rainfall, Generalized Pareto Distribution, Climate
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Colmet-Daage, Antoine. "Les impacts du changement climatique sur les pluies et les inondations extrêmes de bassins versants méso-échelles méditerranéens." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTG020/document.
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Les bassins versants nord-méditerranéens sont fréquemment soumis à des crues extrêmes liées à des précipitations convectives intenses et aux caractéristiques hydrologiques locales. La région méditerranéenne est considérée comme une des régions les plus affectées par le réchauffement climatique, ce qui laisse présager des changements dans le cycle hydrologique. L’objectif de cette thèse CIFRE est d’évaluer les impacts du changement climatique sur les précipitations extrêmes à travers une méthode dite de « futurisation », dans laquelle une fonction de transfert est construite en comparant la distribution des quantiles de précipitations du climat présent et futur. Les impacts du changement climatique sur les précipitations extrêmes sont évalués à travers les simulations à haute résolution EMCORDEX. L’exercice se focalise sur le bassin versant de l’Orbieu dans le sud de la France. La méthode de futurisation est appliquée à six épisodes majeurs de précipitations ayant généré des crues éclair. Les impacts hydrologiques des équivalents statistiques futurs des épisodes de précipitations sont ensuite évalués à travers un modèle hydrologique évènementiel conceptuel. Une estimation des changements d’humidité du sol liés au changement climatique est réalisée et couplée à la quantification des impacts hydrologiques. Le choix d’une modélisation hydrologique conceptuelle a été motivé par ses futures applications opérationnelles. Les conséquences de ce choix sont évaluées à travers une comparaison avec un modèle hydrologique à base physique. Ce dernier est mis en place grâce à une caractérisation du fonctionnement hydrologique du bassin versant de l’Orbieu appuyée par plusieurs campagnes de terrainNorthern mediterranean meso-scale river catchments are submitted to extremes floods events linked to intense convective precipitation and local hydrologic features. The Mediterranean region is known to be one of the most affected areas by global warming, and it is likely that changes can be expected in the hydrological cycle. The aim of this CIFRE thesis is to assess the climate change impacts on extreme precipitation events using a so-called “futurization” method, in which a transfer function is built by comparing the quantiles of distribution for both present and future climate precipitation. The climate change impact on extreme precipitation events is assessed over high-resolution EMCORDEX simulations. The focus is on the Orbieu catchment located in southwestern France. The futurization method is applied to six major events of precipitation that trigger flash floods. The hydrological impacts of those future statistical counterpart precipitation events are therefore assessed through a conceptual event-based hydrological model. An assessment of soil moisture changes under climate change is performed and coupled to the hydrological impact quantification. The conceptual hydrological model chosen, have been motivated by its future operational applications. The consequences of that choice are assessed through a comparison to a physically based hydrological model. It has been implemented through the hydrological functioning caracterisation of the Orbieu catchment supported by several field campaigns
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Medeiros, Vanesca Sartorelli. "Análise estatística de eventos críticos de precipitação relacionados a desastres naturais em diferentes regiões do Brasil." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/3/3147/tde-04102013-113054/.
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A dissertação apresenta um estudo das chuvas extremas relacionadas a quatro desastres naturais ocorridos no Brasil: as inundações do Vale do Itajaí SC, em novembro de 2008, a inundação histórica de São Luís do Paraitinga - SP, em janeiro de 2010, as inundações ocorridas no Vale do Mundaú AL, em junho de 2010 e as inundações e escorregamentos da Região Serrana - RJ, em janeiro de 2011. As chuvas catastróficas foram analisadas através de estatísticas básicas dos dados dos pluviômetros localizados nas regiões. No Vale do Itajaí, as chuvas registradas nos dias 23 e 24 de novembro foram elevadas, atingindo valores acima de 250 mm. Na estação Blumenau, choveu 243,5 mm e 250,9 mm nesses. Na estação localizada em São Luís do Paraitinga, choveu apenas 64,7 mm no dia 1 de janeiro de 2010, quando ocorreu a inundação. Porém, foram observados 205,7 mm em uma das estações localizadas em Cunha. Nesse caso, o elevado volume precipitado na cabeceira da bacia deflagrou as inundações observadas nos dois municípios. No Vale do Mundaú e Paraíba, choveu cerca de 200 mm no dia 5 de junho, em duas das seis estações analisadas. O elevado volume precipitado no dia 5, combinado com as chuvas ocorridas no período de 17 a 19, pode ter causado as inundações observadas no dia 19 nessas bacias. Os dados indicaram que, na Região Serrana do RJ, as inundações e escorregamentos foram causados pela chuva extrema ocorrida nos dias 11 e 12 de janeiro de 2011, que ultrapassou 270 mm no intervalo de 24 h em uma das estações. As chuvas acumuladas nos meses que antecedem os eventos e a alta declividade contribuíram para a saturação do solo e posteriores escorregamentos. Os eventos pluviométricos, classificados através do SPI resultaram, na maioria das estações, chuvas severas ou chuvas extremas A vulnerabilidade das regiões, onde inúmeras habitações estão localizadas em áreas de risco, também foi determinante para que os desastres acontecessem. Outros eventos de magnitude elevada foram observados anteriormente, o que indica que estes eventos são característicos das regiões estudadas. Constatou-se que as regiões analisadas estão sujeitas a chuvas extremas com frequência relativamente alta, muito embora tenha sido observado, em alguns casos, certo grau de raridade nesses eventos. Portanto, nessas áreas devem ser adotadas medidas regionais no sentido de disciplinar o uso e ocupação do solo e reduzir os riscos dos desastres. É fundamental buscar medidas de adaptação da ocupação dessas áreas, considerando o regime hidrológico dessas regiões.The paper presents a study of extreme rainfall related to four natural disasters occurring in Brazil: the floods in Itajaí Valley, state of Santa Catarina, in November, 2008; the historic flood in São Luís do Paraitinga, state of São Paulo, in January, 2010; the floods in Mundaú Valley, state of Alagoas, in June, 2010; and the floods and landslides in the mountainous region of Rio de Janeiro in January, 2011. The catastrophic rains were analyzed through basic statistical data collected from rain gauges located in those regions. In Itajaí Valley, extremely high rainfalls exceeding 250 mm were recorded on November 23 and 24. In Blumenau, it rained 243.5 mm and 250.9 mm on the same days. At the station located in São Luís do Paraitinga, it rained just 64.7 mm on January 1, 2010, when the flood occurred. However, 205.7 mm were observed in one of the stations located in Cunha. In this case, the high volume of rainfall at the headwater of the basin triggered flooding observed in these two cities. In the valleys of Mundaú and Paraíba, it rained nearly 200 mm on June 5, in two of the six stations analyzed. The high volume of rainfall on June 5, combined with the rains from the 17th to the 19th, may have led to the floods in these basins on June 19. The data indicated that, in the mountainous region of Rio de Janeiro, the flooding and landslides were caused by massive rainfall on January 11 and 12, 2011, which exceeded 270 mm within a period of 24 hours in one of the stations. The rainfall accumulated in the months prior to the events and the high sloping land contributed to soil saturation and subsequent landslides. The rainfall events, sorted through the SPI, resulted in severe or extreme rains in most of the stations. The vulnerability of the regions, which include many homes located in hazardous areas, was also crucial for the disasters to happen. Other major events were previously observed, which indicates that these events are characteristic of the studied regions. It was noted that the analyzed regions are subject to extreme rains with a relatively high frequency, although in some cases these events have demonstrated to be somewhat rare. Therefore, in these areas, region-based measures should be adopted with a view to regulating the use and occupation of the soil and reducing risk of disasters. It is essential to seek adaptation measures of occupation of these areas, considering their hydrological regime.
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Rupi, Alberto Pio. "Analisi meteorologica di eventi con precipitazione intensa nell'Italia Centrale." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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In this work we analyze five events of intense precipitation that affected Central Italy between 2011 and 2015. These events caused important flood phenomena, with a significant impact on both the economy and people. This study mainly uses data from ERA5, the latest reanalysis produced by the ECMWF (European Center for Medium-range Weather Forecast), in addition to data from the meteorological network managed by Centro Funzionale of Protezione Civile d’Abruzzo. In the first part is reported an overview of the general issues that characterize the study of intense precipitation events, with a deepening of some recently analyzed cases. Subsequently the data and tools used are reported, with a description of the events studied and the method of investigation. We then go to analyze the synoptic framework in which the event developed and to investigate the causes that generated it. Finally, the precipitation pattern was studied and the degree of reproducibility by the ERA5 reanalysis was tested through a comparison with the meteorological network.
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Vedie, Tómas. "Long and short-term actions taken by NGOs in a post disaster scenario." Thesis, Uppsala universitet, Statsvetenskapliga institutionen, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-379416.
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TimÃteo, SÃsthenis de Lima. "Guidelines struture of water safety Plan for extreme events : droughts and floods. Case study company of the situation room omplementation of Management Water Resources of CearÃ." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13686.
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A Water Safety Plan for Extreme Events - PSAEE, has the purpose of description the procedures in potentially critical situations due to the occurrence of extreme weather
events (droughts and floods). Provides the developing of preventive actions and contingency plan as a way to mitigate the effects of these phenomena. Will be developed in different and complementary steps, aiming anticipation, recognition and risk assessment, identification and monitoring of vulnerable regions and the implementation of a warning network against Floods and Droughts. The present document describes guidelines for structuring a Water Safety Plan for Extreme Events, Floods and Droughts, structured in five (05) steps; 1. Preliminary Steps, 2 Diagnostic System; 3 Operational Monitoring; 4. Management Plans and 5.Validation and Verification. As a case study, the document analyzed the process of implementing the Situation Room of the Water Resources Management Company of Cearà - COGERH , also presenting some suggestion of a Work Plan for the Situation Room, which will serve as a Management Center of Extreme Hydrological Events for the State of CearÃ, Brazil.Um Plano de SeguranÃa de Ãgua para Eventos Extremos â PSAEE, tem como objetivo a descriÃÃo de procedimentos em situaÃÃes potencialmente criticas devido a ocorrÃncia de eventos climÃticos extremos (Secas e Cheias). Prevà o desenvolvendo de aÃÃes preventivas e plano de contingÃncia como forma de mitigar os efeitos destes fenÃmenos. Serà desenvolvido em etapas distintas e complementares, visando a antecipaÃÃo, reconhecimento e avaliaÃÃo de riscos, a identificaÃÃo e monitoramento de regiÃes vulnerÃveis, a implementaÃÃo de rede de alerta contra Cheias e Secas. O presente trabalho descreve diretrizes para estruturaÃÃo de um Plano de SeguranÃa de Ãgua para Eventos Extremos, Cheias e Secas, estruturado em 05 (cinco) etapas; 1. Etapas Preliminares, 2. DiagnÃstico do Sistema; 3. Monitoramento Operacional; 4. Planos de GestÃo e 5. ValidaÃÃo e VerificaÃÃo. Como estudo de caso, o trabalho analisou o processo de implantaÃÃo da Sala de SituaÃÃo da Companhia de GestÃo dos Recursos HÃdricos do Cearà â COGERH, apresentando, tambÃm, sugestÃo de um Plano de Trabalho para a Sala de SituaÃÃo, a qual servirà de Centro de GestÃo de Eventos Extremos HidrolÃgicos para o Estado do CearÃ, Brasil.
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Fouinat, Laurent. "Les territoires de montagne face aux changements globaux : une étude rétrospective autour de la station de ski des Deux Alpes." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAA026/document.
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Ce travail de thèse vise à reconstituer les conditions paléo-environnementales ayant eu lieu dans la vallée de l’Oisans à partir des archives naturelles représentées par les sédiments lacustres. Par une approche multi-marqueurs, nous visons à reconstituer tout à la fois : i) les fluctuations glaciaires en Oisans; ii) les modifications des activités humaines en montagne et leurs influence sur les flux de matière lors d’événements extrêmes ; iii) comprendre la relation entre changements climatiques, changements d’usage et évolution des aléas en haute montagne. Cette étude a permis de mettre en évidence les changements globaux, regroupant la variabilité climatique et les pratiques humaines, ayant influencés l’érosion autour des lacs de La Muzelle et du lac du Lauvitel durant les derniers millénaires.Les résultats principaux ont montrés que l’érosion du lac de la Muzelle a été largement dominé par l’activité glaciaire notamment avec la présence à certaines époques de fines particules détritiques liées à l’abrasion sous glaciaire. Ces dernières ont révélées une relation aux pluies torrentielles encore jamais observées auparavant, leur présence en période d’extension glaciaire étant synonyme d’une augmentation du nombre de dépôts lacustres de crues. Les activités humaines, en majeure partie représentées par l’utilisation agro-pastorale de l’espace avoisinant les lacs, ne sont clairement identifiables que lors des 300 dernières années au lac de la Muzelle. Le lac de Lauvitel est situé à une altitude moindre, dont la majorité du bassin versant est maintenant une réserve intégrale. Les études palynologiques ont mis en évidence certaines périodes d’activités humaines plus marquées. Les événements extrêmes enregistrés dans les sédiments dulac regroupent d’une part les crues, dont l’enregistrement permet une comparaison régionale de l’occurrence de ces événements et de mettre en évidence les changements de circulations atmosphériques à l’échelle des Alpes. D’autre part, les avalanches de neige lourde, dont peu d’enregistrements sont disponibles dans la bibliographie. Nous les avons identifiés grâce à l’utilisation du CT scan l’élaboration d’une nouvelle méthodologie basée sur la différence de densité relative des sédiments. Le comptage et la quantification des apports de matériel détritique grossier aux seins d’une matrice de sédiment lacustre fin, a permis d’identifier les apports liés à cet aléa au cours du temps. Nous avons ensuite reconstitué les événements d’avalanche de neige lourde déposés dans le lac de Lauvitel sur les derniers 3500 ans, dont l’occurrence intervient préférentiellement lors des périodes de retraits glaciairesThis doctoral thesis aims to a paleo-environmental reconstitution of the Oisans valley based on the natural archive of lake sediments. From a multi-proxy approach, we aim to reconstruct: i) Glacial fluctuation reconstruction in Oisans valley; ii) human activities evolution in mountain area and their influences on sediment fluxes especially during extreme events; iii)understand the relationship between climate change, use of mountain lands and natural hazard.Through this study, we identified processes of global change, comprising natural climate variability and human practices, which affected erosion patterns around Lakes Muzelle and Lauvitel during the last millennia. Main results have shown that erosion in the lake Muzelle watershed was dominated in the past by glacial activity, in particular with the presence of fine detrital particles related to subglacial abrasion. They were identified to have a relationship never observed before; during glacial extension their presence is triggering a higher number of flood deposits. At this location, human activities were identified through agro-pastoral activities and more precisely by the coprophilous fungi spore counting, revealing cattle presence since 300 years. Lake Lauvitel is located at lower altitude, which most of the watershed is now situated in an Integral Reserve. Palynological investigations lead to identification of periods of higher human activities in the valley. Extreme events recorded in Lake Lauvitel sediment are on the one hand torrential floods, which allowed a comparison with other reconstructions highlighting changes in the climatic settings in the Alps. On the other hand, wet avalanches deposits were identified with the use of a CT scan and the development of a new methodology based on relative density differences in the sediment. The counting and the quantification of coarse detrital matter within the lacustrine fine sediment matrix allowed income identification of this hazard though time. We then reconstructed wet avalanches events deposited in Lake Lauvitel during the last 3500 years, which occurrence is preferentially during glacial retreats
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Savage, David A. "Decision making under pressure : a behavioural economics perspective." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/64106/1/David_Savage_Thesis.pdf.
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This research investigates the decision making process of individuals from revealed preferences in extreme environments or life-and-death situations, from a behavioral economics perspective. The empirical analysis of revealed behavioral preferences shows how the individual decision making process can deviate from the standard self-interested or “homo economicus” model in non-standard situations. The environments examined include: elite athletes in FIFA World and Euro Cups; climbing on Everest and the Himalaya; communication during 9/11 and risk seeking after the 2011 Brisbane floods. The results reveal that the interaction of culture and environment has a significant impact on the decision process, as social behaviors and institutions are intimately intertwined, which govern the processes of human behavior and interaction. Additionally, that risk attitudes are not set and that immediate environmental factors can induce a significant shift in an individuals risk seeking behaviors.
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Wilhelm, Bruno. "Reconstitution sédimentologique des extrêmes hydrologiques au cours du dernier millénaire dans les Alpes françaises : Relations avec les changements climatiques." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00734248.
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Aujourd'hui une augmentation de l'intensité des extrêmes hydrologiques est attendue avec le réchauffement global. Cependant le manque d'observations des phénomènes torrentiels et de mesures directes des précipitations en altitude sur le temps long ne permet pas d'étayer cette théorie. Les archives naturelles lacustres, par leur capacité à enregistrer l'évolution passée de l'activité torrentielle, offrent l'opportunité de combler ce manque. L'objectif de la thèse est de reconstituer l'évolution de la fréquence et de l'intensité des crues passées, à partir de l'étude de séquences sédimentaires de lacs d'altitude des Alpes Françaises. Afin d'être en mesure d'évaluer le rôle de la température sur l'activité torrentielle, notre étude se focalise sur le dernier millénaire qui a connu des périodes climatiques contrastées ; période chaude de l'Optimum Médiéval (OM), période froide du Petit Age Glaciaire (PAG) et réchauffement global actuel. Les sites d'étude ont été sélectionnés selon un transect nord-sud pour évaluer la variabilité régionale de l'activité torrentielle en réponse aux changements climatiques. Ce travail repose sur des analyses sédimentologiques et géochimiques à haute résolution qui ont permis i) de identifier les dépôts de crue, ii) de les distinguer de dépôts similaires issus de remaniements gravitaires et iii) de déterminer un marqueur fiable de l'intensité des événements. D'autre part plusieurs méthodes de datation ont été combinées dans l'objectif de diminuer les incertitudes des modèles d'âge. La fréquence de crue à l'échelle pluri-séculaire apparaît en augmentation sur l'ensemble des Alpes Françaises au cours de la période froide du PAG. Cependant à l'échelle pluri-décennale la fréquence de crue évolue différemment entre le Nord et le Sud des Alpes. Les maxima de fréquence apparaissent au cours de périodes chaudes dans les Alpes du Nord, alors que les maxima dans les Alpes du Sud semblent correspondre à des phases négatives de l'Oscillation Nord-Atlantique. De plus les événements de crue extrême se produisent au cours des périodes les plus chaudes dans les Alpes du Nord alors qu'ils apparaissent au cours du PAG dans les Alpes du Sud. Ces résultats suggèrent donc une régionalisation des effets du réchauffement global sur les crues extrêmes et les précipitations intenses.
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Younus, Md Aboul Fazal. "Community-based autonomous adaptation and vulnerability to extreme floods in Bangladesh: processes, assessment and failure effects." Thesis, 2010. http://hdl.handle.net/2440/62746.
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The Intergovernmental Panel on Climate Change’s (IPCC) Fourth Assessment Report (2007), especially Chapter 17: Assessment of Adaptation Practices, Options, Constraints and Capacity demonstrates the importance of adaptation to climate change. The IPCC (2007) warned that the megadelta basins in South Asia, such as the Ganges Brahmaputra Meghna (GBM) will be at greatest risk due to increased flooding, and that the region’s poverty would reduce its adaptation capacity. A key issue in assessing vulnerability and adaptation (V & A) in response to extreme flood events (EFEs) in the GBM river basin is the concept of autonomous adaptation.
This thesis investigates autonomous adaptation using a multi-method technique which includes two participatory rapid appraisals (PRA), a questionnaire survey of 140 participant analyses over 14 mauzas in the case study area, group and in-depth discussions and a literature review.
The study has four key approaches. First, it reviews the flood literature for Bangladesh from 1980 to 2009 and identifies a general description of flood hazard characteristics, history and research trends, causes of floods, and types of floods. Second, it examines farmers’ crop adaptation processes in a case study area at Islampur, Bangladesh, in response to different types of EFEs (multi-peak with longer duration flood, single-peak with shorter duration flood and single-peak at the period of harvesting), and describes how farmers have been adapting to the extreme floods over time. Third, it assesses the V&A in response to three EFEs in 1998, 1995 and 1988. V&A are categorized on the basis of a weighted matrix index. The thesis uses PRA methodology and makes an important methodological contribution for assessing V & A. Fourth, the thesis assesses the economic consequences of failure effects of autonomous adaptation in response to EFEs. The results show that Bangladeshi farmers are highly resilient to EFEs, but the economic consequences of failure effects of autonomous crop adaptation (FEACA) on marginal farmers are large. These failure effects are defined as total crop loss against potential production, plus total agricultural cost multiplied by the number of flood events
in the studied area. Total agricultural cost includes cost of seedlings, fertilizer, pesticides, land preparation, human labour, and watering. The thesis estimates that the crop related loss plus plants and houses damaged due to extreme flooding in 1998 in Bangladesh was US$14001.26 million.
The thesis contributes to current knowledge by filling three important research gaps as follows, 1) farmers’ autonomous crop adaptation processes in response to various types of EFEs; 2) methodological contribution for assessing V & A through PRA; and 3) the economic consequences of the failure effects of autonomous crop adaptations. The findings of this study can act as a guide to policy decisions for effective allocation of adaptation funds at community level in Bangladesh. The thesis concludes that urgent action is needed to improve the sustainable crop adaptation capacity at community level in the foreseeable future to cope with extreme floods under a regime of climate change.Thesis (Ph.D.) -- University of Adelaide, School of Social Sciences, 2010
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Ahmed, Khandaker Jafor. "Fertility decisions of women in the context of extreme climate events: A study in two areas hit by cyclones and floods in Bangladesh." Thesis, 2022. https://hdl.handle.net/2440/136539.
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This study investigates to what extent fertility decisions are influenced by extreme climate events in two villages in Bangladesh: Chadnimukha prone to severe cyclones and Lamagaon to floods. Extensive studies have examined the effects of extreme climate events on mortality and migration, but limited research attention has been paid to fertility. This thesis seeks to fill this knowledge gap by examining the fertility decisions of married Bangladeshi women and comparing the differences between the two villages. The study uses a mixed methods approach (quantitative and qualitative analysis) to collect diverse types of information to understand the determinants of fertility in response to extreme climate events. In 2019 to 2020, through fieldwork, primary data were collected in household surveys (N=544) and in-depth interviews (N=74) from married women aged 18 to 49 years with at least one child who were living with their husbands. First, interviews (N=8) were undertaken with key informants and focus group discussions (N=10) were held with male participants to develop a comprehensive understanding of the extreme climate events, their impacts, and typical health issues in the study areas. Secondary data on fertility and extreme climate events were also collected from various sources, including the Bangladesh Meteorological Department, the Centre for Research on the Epidemiology of Disasters, and the World Bank. This study found that women living in the flood-prone village had and intended to have more children than their counterparts in the cyclone-prone village, who were more likely to limit their childbearing. The number of cyclones experienced, household vulnerabilities, the timing of first birth, physiological effects, and seasonal migration tended to limit fertility. Floods, on the other hand, affected fertility due to lack of health facilities and unavailability of contraceptives, risk of infant mortality and preference for sons, which inspired women to have more children. It was also found that the fertility intentions of women in both villages differed according to their experience and perception of extreme climatic events for which their villages were most at risk. In response to extreme climate events on household well-being, including agriculture, livelihoods, housing and food security, women were more likely to delay their next birth for at least two years. However, women from flood-affected households intended to have additional children in response to the effects of floods, either as an insurance measure for the household against the possible loss of a child due to a flood, or as a way to increase family livelihood and security where children could act as potential resources to help families deal with future risks. This research concludes that the type of extreme climate event experienced can determine in what direction and to what extent fertility will change. It also contends that the impact of such events on underlying direct and indirect determinants that influence fertility is distinguishable, and that fertility considerations can and should be incorporated into disaster risk reduction and population policy. With the increasing frequency and severity of climate-related events, policymakers must understand how extreme climate events affect fertility rates in order to provide advice for social and economic development approaches. Furthermore, such information will help to generate population estimates, which can include the consequences of climate change at different stages of demographic change.Thesis (Ph.D.) -- University of Adelaide, School of Social Sciences, 2022
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Shaevitz, Daniel Albert. "Extreme weather: subtropical floods and tropical cyclones." Thesis, 2016. https://doi.org/10.7916/D8BC3ZTD.
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Extreme weather events have a large effect on society. As such, it is important to understand these events and to project how they may change in a future, warmer climate. The aim of this thesis is to develop a deeper understanding of two types of extreme weather events: subtropical floods and tropical cyclones (TCs).
In the subtropics, the latitude is high enough that quasi-geostrophic dynamics are at least qualitatively relevant, while low enough that moisture may be abundant and convection strong. Extratropical extreme precipitation events are usually associated with large-scale flow disturbances, strong ascent, and large latent heat release. In the first part of this thesis, I examine the possible triggering of convection by the large-scale dynamics and investigate the coupling between the two. Specifically two examples of extreme precipitation events in the subtropics are analyzed, the 2010 and 2014 floods of India and Pakistan and the 2015 flood of Texas and Oklahoma. I invert the quasi-geostrophic omega equation to decompose the large-scale vertical motion profile to components due to synoptic forcing and diabatic heating. Additionally, I present model results from within the Column Quasi-Geostrophic framework. A single column model and cloud-revolving model are forced with the large-scale forcings (other than large-scale vertical motion) computed from the quasi-geostrophic omega equation with input data from a reanalysis data set, and the large-scale vertical motion is diagnosed interactively with the simulated convection. It is found that convection was triggered primarily by mechanically forced orographic ascent over the Himalayas during the India/Pakistan flood and by upper-level Potential Vorticity disturbances during the Texas/Oklahoma flood. Furthermore, a climate attribution analysis was conducted for the Texas/Oklahoma flood and it is found that anthropogenic climate change was responsible for a small amount of rainfall during the event but the intensity of this event may be greatly increased if it occurs in a future climate.
In the second part of this thesis, I examine the ability of high-resolution global atmospheric models to simulate TCs. Specifically, I present an intercomparison of several models' ability to simulate the global characteristics of TCs in the current climate. This is a necessary first step before using these models to project future changes in TCs. Overall, the models were able to reproduce the geographic distribution of TCs reasonably well, with some of the models performing remarkably well. The intensity of TCs varied widely between the models, with some of this difference being due to model resolution.
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Diehl, Timothy Hunter. "Hydrological and statistical characteristics of extreme floods." 1990. http://catalog.hathitrust.org/api/volumes/oclc/22948282.html.
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Thesis (Ph. D.)--University of Wisconsin--Madison, 1990.Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 151-158).
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Hussain, Sk Ghulam. "Decision support system for assessing rice yield losses from annual flooding in Bangladesh." Thesis, 1995. http://hdl.handle.net/10125/9274.
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Nakamura, Jennifer Anne. "Hydroclimatology of Extreme Precipitation and Floods Originating from the North Atlantic Ocean." Thesis, 2014. https://doi.org/10.7916/D86H4FM1.
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This study explores seasonal patterns and structures of moisture transport pathways from the North Atlantic Ocean and the Gulf of Mexico that lead to extreme large-scale precipitation and floods over land. Storm tracks, such as the tropical cyclone tracks in the Northern Atlantic Ocean, are an example of moisture transport pathways. In the first part, North Atlantic cyclone tracks are clustered by the moments to identify common traits in genesis locations, track shapes, intensities, life spans, landfalls, seasonal patterns, and trends. The clustering results of part one show the dynamical behavior differences of tropical cyclones born in different parts of the basin. Drawing on these conclusions, in the second part, statistical track segment model is developed for simulation of tracks to improve reliability of tropical cyclone risk probabilities. Moisture transport pathways from the North Atlantic Ocean are also explored though the specific regional flood dynamics of the U.S. Midwest and the United Kingdom in part three of the dissertation.
Part I. Classifying North Atlantic Tropical Cyclones Tracks by Mass Moments.
A new method for classifying tropical cyclones or similar features is introduced. The cyclone track is considered as an open spatial curve, with the wind speed or power information along the curve considered as a mass attribute. The first and second moments of the resulting object are computed and then used to classify the historical tracks using standard clustering algorithms. Mass moments allow the whole track shape, length and location to be incorporated into the clustering methodology. Tropical cyclones in the North Atlantic basin are clustered with K-means by mass moments producing an optimum of six clusters with differing genesis locations, track shapes, intensities, life spans, landfalls, seasonality, and trends. Even variables that are not directly clustered show distinct separation between clusters. A trend analysis confirms recent conclusions of increasing tropical cyclones in the basin over the past two decades. However, the trends vary across clusters.
Part II: Tropical cyclone Intensity and Track Simulator (HITS) with Atlantic Ocean Applications for Risk Assessment.
A nonparametric stochastic model is developed and tested for the simulation of tropical cyclone tracks. Tropical cyclone tracks demonstrate continuity and memory over many time and space steps. Clusters of tracks can be coherent, and the separation between clusters may be marked by geographical locations where groups of tracks diverge due to the physics of the underlying process. Consequently, their evolution may be non-Markovian. Markovian simulation models, as often used, may produce tracks that potentially diverge or lose memory quicker than nature. This is addressed here through a model that simulates tracks by randomly sampling track segments of varying length, selected from historical tracks. For performance evaluation, a spatial grid is imposed on the domain of interest. For each grid box, long-term tropical cyclone risk is assessed through the annual probability distributions of the number of storm hours, landfalls, winds, and other statistics. Total storm length is determined at birth by local distribution, and movement to other tropical cyclone segments by distance to neighbor tracks, comparative vector, and age of track. An assessment of the performance for tropical cyclone track simulation and potential directions for the improvement and use of such model are discussed.
Part III: Dynamical Structure of Extreme Floods in the U.S. Midwest and the United Kingdom.
Twenty extreme spring floods that occurred in the Ohio Basin between 1901 and 2008, identified from daily river discharge data, are investigated and compared to the April 2011 Ohio River flood event. Composites of synoptic fields for the flood events show that all these floods are associated with a similar pattern of sustained advection of low-level moisture and warm air from the tropical Atlantic Ocean and the Gulf of Mexico. The typical flow conditions are governed by an anomalous semi-stationary ridge situated east of the US East Coast, which steers the moisture and converges it into the Ohio Valley. Significantly, the moisture path common to all the 20 cases studied here as well as the case of April 2011 is distinctly different from the normal path of Atlantic moisture during spring, which occurs further west. It is shown further that the Ohio basin moisture convergence responsible for the floods is caused primarily by the atmospheric circulation anomaly advecting the climatological mean moisture field. Transport and related convergence due to the covariance between moisture anomalies and circulation anomalies are of secondary but non-negligible importance. The importance of atmospheric circulation anomalies to floods is confirmed by conducting a similar analysis for a series of winter floods on the River Eden in northwest England.
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Huang, Pei-Yi, and 黃佩儀. "Building Damage and Loss for Extreme Flash Floods Triggered by Dam Breach." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/d423c2.
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碩士國立臺灣大學
土木工程學研究所
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Dam breach with great amount of water destroys downstream areas heavily and poses a huge threat to lives, infrastructures and residential buildings in affected areas. The thesis simulates the plausible damage to buildings after dam breach including the damage level to buildings and monetary loss. The thesis simulate two potential scenarios of embankment dam breach would take place, which are gradual erosion of dam and sudden collapse of dam. Then, an easy-implemented dam breach model are conducted in Taiwan and Germany. Further, the inundation mappings are shown at the platform of Arc-GIS so as to calculate the inundation height and flow velocity to buildings. By virtue of the Flood damage functions established by EDAC (Earthquake Damage Analysis Center), the potential mean damage map and the loss to buildings are obtained. In addition, the fragility functions derived by 2011 Japan Tsunami is carried out to compare with the EDAC functions. As the results show, buildings in Taiwan and Germany suffer moderate damage which means that primary columns or walls are ruined. The understanding of damage to buildings due to dam breach through the thesis is also expected to assist the planning and management of water resource systems.
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Choudhury, Mahed-Ul-Islam. "Wetland-community resilience to flash flood hazards (Bonna) in Sunamganj district, Bangladesh." 2016. http://hdl.handle.net/1993/30998.
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The purpose of this thesis research was to understand the recovery and resilience of wetland-community to flash flood disasters and its associated risks in the north-eastern part of Bangladesh. I conducted my study using a case study approach following an interdisciplinary research paradigm. It was found that wetland-community is extremely vulnerable to flash flood hazards - both in biophysical and social terms. However, they possess certain coping thresholds, and are resilient to disaster losses. The adaptive capacity of the local communities has been severely curbed by a number of socio-ecological, economic, and political factors, leading to natural resource degradation, marginalization and exclusion of the poor from common pool resources by powerful groups. Response capacities of local institutions were severely constrained by their limited relative autonomy. For building resilience, i) effective management and access of the poor to natural resources, and ii) enhancing autonomy of local institutions are required.February 2016
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"Policy Change and Policy Learning in a New Democracy: Response to Extreme Floods in Hungary." Diss., 2009. http://hdl.handle.net/10161/1109.
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Albright, Elizabeth Ann. "Policy Change and Policy Learning in a New Democracy: Response to Extreme Floods in Hungary." Diss., 2009. http://hdl.handle.net/10161/1109.
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Climate scientists predict increases in frequency and intensity of extreme climatic events over the next century. I used the policy change and policy learning theoretical frameworks--predominantly the advocacy coalition framework (ACF) and the focusing event literature--along with the literature on stakeholder participatory processes, to analyze what policy change occurs and what is learned as a result of experiencing extreme and damaging events. I analyze change in response to catastrophe by examining the response of national and local governments to a series of extreme floods (1998-2002) in a newly democratizing nation, Hungary. I used both qualitative analysis--examination of case studies based on data collected in semi-structured interviews with key informants in the flood and water policy domain--and quantitative analysis--based on a survey of mayors of towns (n=141) in two river basins that had experienced varying degrees of flooding. From these analyses I conclude that the experience of extreme and damaging floods alone was not sufficient to produce policy change and learning. But, a number of factors in concert with the extreme events enabled policy change to occur: (1) The process of democratization allowed alternative voices to be heard in national-level flood policy discussions. (2) A coalition of individuals and organizations espousing an ecological alternative to traditional engineering approaches to flood management that coalesced to press for policy change after the floods occurred. (3) Key policy entrepreneurs, both inside and outside of government, enabled a radical shift in flood management toward the ecological approach. and (4) Scientific information gathered by local environmental activists facilitated in-depth discussions about flood management alternatives. In 2003 Hungary enacted a more comprehensive flood management plan that included economic development and environmental protection goals, but only the flood protection aspects of the plan had been implemented by 2007. At the local level, towns and cities adopted new policies in response to the extreme floods, but these changes focused on emergency response and flood protection policies. These findings suggest that while it may be comparatively easy to adopt new policies, changing long-held beliefs and practices about how rivers and floods should be managed is a much more difficult task.
Dissertation
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Moniruzzaman, Md. "The impact of extreme climatic events on migration from two communities in Bangladesh." Thesis, 2015. https://researchonline.jcu.edu.au/46523/1/46523-moniruzzaman-2015-thesis.pdf.
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The latest IPCC Report (Adger et al 2014) identifies climate change and climate variability as important factors for human security because of the capacity to undermine livelihoods, compromise culture and identity, and increase migration. Although the predicted global patterns of extreme climatic events appear to have changed with some strong cyclones and floods already occurring; a strong relationship between extreme climatic events and climate change is not fully established (IPCC 2014). Adger et al (2014) suggest in all regions of the world, migration serves as a mechanism for adapting to extreme climatic events, be it temporary or permanent, and that our understanding of the potential influence of climate change on migration can be enhanced by an understanding of the impacts of extreme climatic events on migration. This understanding would need to include sending and destination communities, especially if there is the potential for policy interventions.
This study investigates contributions to migration in areas affected by extreme climatic events as a proxy for understanding the potential impacts of climate change on migration. That is, whether people have already started migrating as a result of extreme climatic events, or they are moving because of other factors that have contributed to migration (Adger et al., 2014).
Bangladesh, as one of the most climatically impacted countries of the world, has been selected as a case study for this research. Within Bangladesh, two communities consistently affected by climatic factors such as cyclone and tidal surges, and flood and river bank erosion are chosen as locations for this research. Semi-structured questionnaires and Focus Group Discussions (FGD) were used to collect data in both communities. Qualitative analysis was employed to elaborate the outcomes.
Consistent with the view that migration is most likely to be a consequence of complex interactions of a number of factors (Adger et al 2014), results show that anthropogenic causes, such as government policy implementation to protect the Sundarbans, the largest mangrove forest of the world, and changing paddy cultivation fields into saline fish farming have contributed to migration. Additionally, natural hazards such as periodic floods, river bank erosion, cyclones and tidal surges have all damaged the territory of poor workers and/or daily labourers leading them to move to places where employment is more available. In this regard, extreme climatic events have played a fundamental and influential role with other factors in the process of migration. Results also indicate that transportation costs and social networks are fundamental requirements for migration. Moreover, a number of migrants from the riverine community have built their own strong community and business sectors in the places of destination. Nevertheless, negative consequences such as conflicts, insecurities, and threats to the migrants were also seen where the community of migrants is not strong at the destinations.
This study has contributed to filling a research gap about the relationship between extreme climatic events and migration in the coastal and riverine communities of Bangladesh and has provided a significant contribution to the theories of migration with regard to push-pull factors, intervening factors and the consequences of potential climate induced migration that can inform and facilitate the basis of local government policy and planning, and human settlement planning.
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Monteiro, João Nuno Gomes. "Effect of extreme climatic events on Carcinus maenas population in the Mondego estuary." Master's thesis, 2019. http://hdl.handle.net/10316/88021.
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Dissertação de Mestrado em Ecologia apresentada à Faculdade de Ciências e TecnologiaEventos climáticos extremos têm vindo a aumentar a sua frequência e intensidade nas últimas décadas. Deste modo, é importante compreender como estes afetam as espécies e habitats. O objetivo deste estudo foi analisar a variação temporal e espacial na dinâmica populacional de Carcinus maenas no estuário do Mondego, e os efeitos dos eventos climáticos extremos (secas e cheias) nesta população. As amostragens foram realizadas mensalmente durante os anos de 2003 a 2018 (exceto 2012 e 2013), durante a noite com o auxílio de uma rede de arrasto de vara de 2 metros. As densidades de C. maenas foram padronizadas em indivíduos por 1000m2. Analisando as densidades de juvenis observou-se a existência de um padrão de recrutamento contínuo ao longo de todo o estudo, com picos de recrutamento em anos de secas, além disso, é observável que os juvenis se encontram maioritariamente em zonas mais a montante do estuário. A população é constituída essencialmente pelo morfótipo verde, encontrando-se os indivíduos com morfótipos laranjas e vermelhos em zonas mais a jusante do estuário. O ratio sexual (machos/fêmeas) foi diferente conforme as classes de tamanho, apresentando valores superiores a 1 nas primeiras classes de tamanho, mostrando posteriormente, um equilíbrio do número de machos e fêmeas. A produção secundária (P) estimada para C. maenas foi diferente durante todos os anos do estudo, tendo valores superiores em anos de secas. Os diagramas de ordenação (RDA) mostraram as diferenças espaciais, temporais e ambientais de Carcinus maenas no estuário do Mondego. Através da análise das somas acumulativas (CUSUM) verificou-se uma correlação entre a maioria das características biológicas de C. maenas e as variáveis ambientais e o índice de oscilação norte atlântico (índice NAO). Avaliando as diferentes populações de caranguejo verde no planeta, observaram-se claras diferenças no período de recrutamento, no tamanho máximo dos indivíduos e na esperança média de vida. As populações do Sul da Europa apresentam menores tamanhos máximos e um maior período de recrutamento. Com o aumento da latitude, observa-se populações com maiores tamanhos máximos e com um menor período de recrutamento. A existência de eventos climáticos extremos leva à alteração da dinâmica populacional de Carcinus maenas, sendo que as maiores diferenças são observáveis durante secas extremas, onde devido à diminuição do caudal do rio e ao aumento da salinidade, irá existir um maior recrutamento de juvenis, levando assim a um aumento da densidade populacional.
Extreme climate events have been increasing in frequency and intensity in the last decades. So, it is important to understand how these affect species and habitats. The objective of this study was to analyse the temporal and spatial variation in the population dynamics of Carcinus maenas in the Mondego estuary and the effect of extreme climate events (droughts and floods) on this population. Samplings were performed monthly during the years 2003 to 2018 (except 2012 and 2013), with a 2-meter beam trawl during the night. The densities of C. maenas were standardized in individuals per 1000m2. Analysing juvenile densities, a continuous recruitment pattern was observed throughout the study, with recruitment peaks in years of droughts, in addition, it was observable that juveniles are found mainly in upstream areas of the estuary. The population consists essentially on the green morphotype, being the orange and red morphotypes present in more downstream areas of estuary. The sex ratio (males/females) was different according to the size classes, being much higher than 1 in the first size classes, showing afterwards, in older individuals a value close to 1. The secondary production (P) estimated for C. maenas was different during all the period, having higher values in droughts years. The ordering diagrams (RDA) showed spatial, temporal and environmental differences of Carcinus maenas in the Mondego estuary. A correlation between Carcinus maenas biological features and the environmental variables and the North-Atlantic Oscillation index (NAO index) was verified through the cumulative sums analysis (CUSUM). The different populations of the green crab on the planet, showed clear differences in the recruitment period, the maximum size of the individuals and the life span. Southern European populations have lower maximum carapace width and a longer recruitment period. With the increase of latitude, populations with larger maximum carapace width and with a shorter recruitment period were observed. The existence of extreme climate events causes leads to an adjustment on the population dynamics of Carcinus maenas. Bigger differences are present during extreme droughts, where due to the low river flow and an increase in the salinity, there will be a more intense recruitment of juveniles, leading to an increase in population density.
FCT
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Maposa, Daniel. "Statistics of extremes with applications to extreme flood heights in the Lower Limpopo River Basin of Mozambique." Thesis, 2016. http://hdl.handle.net/10386/1695.
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Thesis (Ph. D. (Statistics)) -- University of Limpopo, 2016.Statistics of extremes has seen much growth both in theory and application since its early theoretical developments almost a century ago in the 1920s and its first major applications to real-life problems pioneered by Emil Gumbel in the early 1940s. Although the theory and applications of extreme value theory (EVT) have been extensively advanced and utilised in most developed countries,intermsofapplicationslittlehasbeendoneinmanydevelopingcountries in Africa despite the abundance of areas of applications and raw data in some ofthesecountries. Inhydrology,thechoiceoffloodfrequencyprobabilitydistributions for a particular site or region remains the subject of ongoing research. The work contained in this thesis is a contribution towards this area and it addresses this problem in one of the developing and economically challenged countries in Africa, Mozambique, in the lower Limpopo River basin (LLRB). The LLRB is a basin characterised by extreme natural hazards, alternating between extreme floods and severe droughts. ThisthesisisbasedonanextensiveapplicationofEVTtoextremefloodheights data in the LLRB of Mozambique at three sites: Chokwe, Combomune and Sicacate hydrometric stations. Two fundamental approaches of EVT, block maxima and peaks-over-threshold (POT), are used in this thesis. Recent theoretical results by Ferreira and de Haan (2015) have shown that despite its inefficiency due to data lost as a result of blocking, the block maxima approach is more efficient in a number of situations than the POT approach, and the two approaches are quite comparable for large sample sizes. A number of ii candidate distributions are investigated for their goodness-of-fit to the annual daily maximum flood heights in a block maxima realisation at each site. The findings reveal that the GEV distribution is the most appropriate distribution to apply in the LLRB and the distribution can be recommended as the likelihood function for regional and spatial extremes flood frequency analysis in the basin. The thesis addresses the issue of cumulative effects on daily flood heights through a comparative analysis of six annual maxima moving sums. The findings demonstrate that the six annual maxima time series models are notsignificantlydifferentbasedonthecharacteristicsconsideredinthisthesis. In an attempt to reduce uncertainties in the estimates, a Bayesian Markov chain Monte Carlo (MCMC) approach with a conjugate prior and a GEV likelihood function is used to model the tails of the extreme flood heights in the basin. The findings reveal that the addition of prior information in Bayesian MCMC substantially reduces uncertainties in the estimates and improves precision in the predicted extreme floods. The r largest order statistics models developed in this thesis are generally promising and the standard errors of the estimates of the parameters are substantially reduced. In order to account for climate change impact, nonstationary models are considered with the longterm trend and seasonal oscillation index (SOI) (a meteorological variable indicator) as covariates of the parameters of the GEV distribution and the generalised Pareto distribution (GPD). Among the major contributions of this thesis is a proposed procedure for the determination of the 8 days window period used in extracting independent r largest order values within the same year for the r largest order statistics approach. A summary of the key findings and contributions of this thesis are given in Chapter 9. Moreover, contributions by the study topic in each chapter are given at the end of each chapter.
DST-NRF Centre of Excellence in Mathematical and Statistical Sciences (CoEMaSS) of South Africa
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Fox, R. C., and Kate Rowntree. "Extreme weather events in the Sneeuberg, Karoo, South Africa: a case study of the floods of 9 and 12 February 2011." 2013. http://hdl.handle.net/10962/d1004468.
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Two destructive flood events occurred in rapid succession in the semi-arid Sneeuberg Mountains of the Karoo, South Africa in February 2011. The temporal and spatial characteristics of these two extreme events are examined in this paper through analysis of data from an unusually dense, and reliable, network of farm rain gauges. These analyses add to our understanding derived from existing rain gauge information. Comparisons are then made with patterns from a range of modeled products derived from remote sensed information: the Modern-Era Retrospective Analysis for Research and Applications (MERRA), the Tropical Rainfall Measuring Mission (TRMM) and the Global Land Data Assimilation System (GLDAS). We found that the first flood event was widespread and precipitation was related strongly to altitude. The second was highly localised, with no relationship to altitude. Both had very sharply peaked rainfall intensities. These findings are of significance to the studies of flooding and landscape change in the area as such events have become more pronounced over the past 50 yr and it is likely that this trend will accelerate. The modeled patterns are derived largely from remote sensing and we found that they are reliable for drawing out monthly and annual variations but they make noticeable underestimates. They are poor estimates, however, both for the spatial distribution of precipitation, and the short term trends as they struggle to estimate the impact of topography and other local forcing factors. This finding corroborates information derived from other analyses at broader spatial scales using more widely spread, established rain gauge stations. Ten percent of southern Africa has been classified as mountainous and these areas provide much of our water resources so our findings are significant to water managers throughout this and similar mountainous regions.
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"Variations of extreme precipitation and temperature and implications on floods and droughts under the changing climate in China in the 21st century." 2015. http://repository.lib.cuhk.edu.hk/en/item/cuhk-1292123.
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Li, Jianfeng.Thesis Ph.D. Chinese University of Hong Kong 2015.
Includes bibliographical references (leaves 182-198).
Abstracts also in Chinese.
Title from PDF title page (viewed on 03, January, 2017).
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Rayhan, Israt [Verfasser]. "Assessing household vulnerability and coping strategies to floods : a comparative study of flooded and non-flooded areas in Bangladesh, 2005 / von Israt Rayhan." 2008. http://d-nb.info/990934632/34.
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Kajambeu, Robert. "Modelling flood heights of the Limpopo River at Beitbridge Border Post using extreme value distributions." Diss., 2016. http://hdl.handle.net/11602/676.
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MSc (Statistics)Department of Statistics
Haulage trucks and cross border traders cross through Beitbridge border post from landlocked countries such as Zimbabwe and Zambia for the sake of trading. Because of global warming, South Africa has lately been experiencing extreme weather patterns in the form of very high temperatures and heavy rainfall. Evidently, in 2013 tra c could not cross the Limpopo River because water was owing above the bridge. For planning, its important to predict the likelihood of such events occurring in future. Extreme value models o er one way in which this can be achieved. This study identi es suitable distributions to model the annual maximum heights of Limpopo river at Beitbridge border post. Maximum likelihood method and the Bayesian approach are used for parameter estimation. The r -largest order statistics was also used in this dissertation. For goodness of t, the probability and quantile- quantile plots are used. Finally return levels are calculated from these distributions. The dissertation has revealed that the 100 year return level is 6.759 metres using the maximum likelihood and Bayesian approaches to estimate parameters. Empirical results show that the Fr echet class of distributions ts well the ood heights data at Beitbridge border post. The dissertation contributes positively by informing stakeholders about the socio- economic impacts that are brought by extreme flood heights for Limpopo river at Beitbridge border post
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Sikhwari, Thendo. "Variability and long-term trends of climate extremes over the Limpopo, South Africa." Diss., 2019.
Find full textAbstract:
MENVSCDepartment of Geography and Geo-Information Sciences
Climate change has a crucial impact on livelihoods, economy, and water resources due to the occurrence of weather and climate extreme events such as floods, droughts and heat waves. Extreme weather has been increasing worldwide, hence the need to understand their nature and trends. The aim of this study was to analyse the spatial variability and long-term trends of climate extremes over the Limpopo in South Africa from 1960 to 2014. Rainfall, temperature, and circulation fields were analysed to understand the extent, nature of climate extremes over the Limpopo. Extreme value theory (EVT) is a powerful method that was also employed in this study to provide statistical models for events rarely observed. R statistical software was used for clustering analysis which has a variety of functions for cluster analysis. Any station whose value is larger than 95th for any day of the season was considered as a widespread extreme event. The results show that the study area is highly vulnerable to extreme events due to its latitudinal location and low altitude. Anomalous cut-off lows, tropical cyclones and tropical storms are the major extreme producing systems affecting the Limpopo province whilst the Botswana High becomes dominant during heat waves and drought. Extreme weather events are common in Limpopo during summertime and often coincide with mature phases of the El Nino Southern Oscillation. In this study, after the suitable model for data was chosen, the interest was in deriving return levels of extreme maximum rainfall. The computed data for return levels predicted that the 5-year return period’s return level is approximately 223.89 mm, which suggests that rainfall of 223.89 mm or more per month should occur at that station or location on the average of once every five years.
NRF
http://hdl.handle.net/11602/1485
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Klášterková, Hana. "Současný stav vegetace v nivě Sázavy po jarní povodni v roce 2006." Master's thesis, 2020. http://www.nusl.cz/ntk/nusl-435851.
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In this diploma thesis current state of vegetation cover was analyzed after spring flood in 2006 on the lower section of the Sázava river. Immediately after the flood there were 38 sites with alluvial deposits identified in the floodplain. The differences in species composition and species diversity between sites with alluvial deposits and sites without deposits were analyzed. The data were collected by using phytosociological relevés in pairs i.e. - plot with an alluvial deposit and plot without. There were 86 vascular plant species recorded out of which 10 species were non-native but not invasive species and 7 species were non-native invasive species. Results of this thesis revealed that species composition and diversity of invasive species differ between plots with alluvial deposits and plots without alluvial deposits. Moreover, plots without alluvial deposits host more invasive species. Keywords: vegetation succession, river floodplain, extreme floods, species diversity, plant invasion
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Gvoždíková, Blanka. "Vztah anomálií toků vlhkosti, extrémních srážek a povodní ve střední Evropě." Doctoral thesis, 2021. http://www.nusl.cz/ntk/nusl-438700.
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Floods associated with extreme precipitation are one of the most serious natural hazards, which produce substantial human and socio-economic losses in central Europe. One way to reduce the impact of flooding is by increasing preparedness with better flood forecasts and warnings, which is not possible without a proper understanding of physical processes leading to a flood hazard. However, frequent research on floods in relation to causal precipitation and synoptic conditions is usually carried out regionally, although some events often affect areas of a size of entire countries or even larger. The thesis was focused exactly on these large-scale precipitation and flood events that occurred in the second half of the 20th century and then until 2013, for which the size of the affected area is as crucial in the extremity assessment as the magnitude of flood discharges or precipitation totals. The extremity indices used for the assessment of extreme precipitation and flood events connected both aspects. The larger area of interest defined within central Europe allowed examining the spatial structure of events, the differences between them, and their relation to conditions in the atmosphere. To connect the extremes of precipitation with extremes in atmospheric conditions, the causal circulation was...
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Gonçalves, Filipa Daniela Rodrigues. "Análise da vulnerabilidade a extremos climáticos na Vila de Póvoa de Lanhoso." Master's thesis, 2017. http://hdl.handle.net/1822/46436.
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Dissertação de mestrado em Geografia (área de especialização em Planeamento e Gestão do Território)As mudanças climáticas decorrentes do aquecimento global têm implicações sobre as comunidades locais. Num curto espaço de tempo, as alterações climáticas passaram para o centro do debate público, como o maior desafio do século XXI. O estudo da vulnerabilidade, enquanto área científica em expansão, converge métodos e técnicas das ciências naturais e sociais, aplicadas nesta investigação à escala local, na Área de Reabilitação Urbana (ARU) da Póvoa de Lanhoso. Em termos gerais, o desígnio desta dissertação prende-se com a análise e avaliação da vulnerabilidade aos extremos térmicos (calor) e hidroclimáticos (inundações, alagamentos), paroxismos recorrentes que afetam as sociedades atuais. A metodologia desenvolvida projeta e adapta a produção científica relativa às componentes da exposição, sensibilidade e capacidade de adaptação, incluindo ao mesmo tempo dados biofísicos e socioeconómicos, numa abordagem sensível às condições locais e dinâmicas existentes, aplicável ao planeamento urbano. A unidade de análise adotada corresponde à subseção estatística, tendo-se recorrido à análise espacial de um conjunto de indicadores que sintetizam cada uma das três componentes da vulnerabilidade. Os resultados obtidos permitem identificar os espaços mais vulneráveis e problemáticos em relação aos referidos extremos, que incidem sobretudo nas áreas mais antigas e centrais da ARU. Além disso, analisaram-se as condições locais de regulação térmica e hidrológica, como forma de identificar as áreas com aptidão para atenuar a vulnerabilidade e os impactes potenciais dos extremos climáticos estudados. Os resultados correspondentes a esta análise apontam o centro urbano consolidado como a área mais problemática da ARU, onde a vulnerabilidade é elevada e as caraterísticas biofísicas e ambientais determinam capacidades reguladoras insuficientes. Relativamente à priorização da intervenção ao nível do planeamento e da reabilitação urbana, com o objetivo de reduzir a vulnerabilidade aos extremos climáticos na ARU, consideraram-se como áreas prioritárias as subseções estatísticas com elevada vulnerabilidade e fraca regulação térmica e/ou hidrológica, sendo que se evidenciaram quatro subseções estatísticas do centro urbano consolidado nesta situação.
Climate change resulting from global warming have implications on local communities. In a short period of time, climate change moved to the center of public debate as the biggest challenge of the XXI century. The study of vulnerability, as an expanding scientific area, converges methods and techniques of both natural and social sciences, which were applied in this investigation at the local scale, in the Urban Reabilitation Area (ARU) of Póvoa de Lanhoso. In general terms, the design of this work relates to the analysis and assessment of vulnerability to thermal extremes (heat) and hydro-climatic extremes (flooding), which are recurrent paroxysms that affect contemporary societies. The methodology adapts the scientific production related to exposure, sensitivity and adaptation capacity components of vulnerability, and includes both biophysical and socio-economic data in an approach to local conditions and existing dynamics, applicable to urban planning. Spatial analysis based on a set of indicators that synthesize each of the three vulnerability components was applied to statistical subsections level. Results allow the identification of the most vulnerable and problematic areas in relation to the studied extremes, which are confined to ARU’s oldest and most central areas. Furthermore, local conditions of thermal and hydrological regulation were examined, as a way of identifying areas with the ability to lower vulnerability and to mitigate potential impacts of climate extremes. Corresponding results point out the consolidated urban center as being the most problematic area of ARU, where vulnerability is high and its biophysical and environmental features determine an insufficient regulatory capacity. With regard to priorization of urban planning and rehabilitation interventions, in order to reduce vulnerability to climate extremes in ARU, statistical subsections with high vulnerability and weak thermal and/or hydrological regulation were considered as priority areas. This final analysis put into evidence four statistical subsections on the urban center.