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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Beyond bigger and better: Gilbert White and America's new approach to floodplain management

Rumsey, Brian Edward 01 May 2010 (has links)
Until the early twentieth century, Americans generally responded to the risk of floods by building protective levees. By the late 1800s, this approach was firmly entrenched in federal policy. Because of the singular focus on levees, floods actually became more severe, with a prime example occurring in 1927. The floods of 1927 demonstrated that levees-only was an untenable policy, but a new approach to managing flood risk took several decades to fully materialize. The geographer Gilbert Fowler White played a central role in developing the nation’s new approach to floods. In his 1945 doctoral dissertation, White laid out a multiaceted approach to flood risks that promoted the accommodation of nature at times, rather than relying exclusively on ever-greater works of engineering to address the risk of flood. The passage of the National Flood Insurance Act in 1968 demonstrates the acceptance of White’s ideas into federal policy.
82

Floodwaters and vehicle hydrodynamics: A deep dive into risk mitigation unraveling vehicle stability in floods

Al-Qadami, E., Razi, M.A.M., Shah, S.M.H., Pu, Jaan H., Amran, M., Huenchuan, M.A.D., Avudaiappan, S. 08 July 2024 (has links)
Yes / Vehicles are frequently impacted objects during floods, susceptible to being washed away when the flow velocity and water depth surpass specific thresholds. Thus, understanding the characteristics of vehicle instability in floodwaters is crucial for establishing effective safety guidelines. This paper presents a comprehensive review, delving into previous studies on flooded vehicle stability during flood events and assessing progress in guideline formulation spanning from 2010 to 2023. According to the literature, 78 % of the previous investigations focused on the stability of static vehicles, while only 22 % considered vehicles in motion. Previous studies on vehicle stability during tsunamis have not been well-explored. Moreover, emergency vehicles, including police cars, fire trucks, and ambulances, received little attention and were only considered in two studies. On the other hand, extensive research has been conducted on defining the critical vehicle orientation with respect to incoming flow, which is reported to occur when the flow direction is perpendicular to the longitudinal vehicle axis. However, it is expected that this review will serve as a foundational resource, inspiring researchers to identify areas requiring attention and delve deeper into producing general safety guidelines. The ultimate goal is to prevent fatalities related to flooded vehicles and contribute to the broader field of flood risk mitigation.
83

Flexibility in Emergency Management: Exploring the Roles of Spontaneous Planning and Improvisation in Disaster Response

Gutierrez, Miguel 12 1900 (has links)
One of the long-standing debates in disaster science and practice is the tension between planning and structure on the one hand and flexibility and adaptation on the other in maximizing the effectiveness of response operations. This research aims to reconcile the divide that currently exists among scholars and practitioners and present a continuum that bridges the above models and ties planning, improvisation, and spontaneous planning together. The main questions that were examined with this research are: First, what role did spontaneous planning and improvisation play in responding to the two disasters. Second, in what ways do hazard characteristics (e.g. speed of onset and scope of impact) influence the roles played by spontaneous planning and improvisation? This is a qualitative study that employed a comparative case study to examine the characteristics of spontaneous planning. The major findings are that spontaneous planning does occur and that variables such as speed of onset, scope, magnitude, and number of organizations involved impact the visibility of spontaneous planning characteristics.
84

Extreme weather: subtropical floods and tropical cyclones

Shaevitz, Daniel Albert January 2016 (has links)
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.
85

The impact of the Okavango River on the health of the community of Sepopa Village in the Okavango District, Botswana

Mosarwana, Ketlabareng Peaceful January 2015 (has links)
Thesis (MPH.) -- University of Limpopo, 2015 / Introduction: A qualitative study was undertaken to assess the impact that flooding of the Okavango river have on the health of the community of Sepopa village. Aim: To assess the impact that flooding of the Okavango River has on the health of the community of Sepopa village. Study: the study was conducted in the village of Sepopa within the community aged between fifteen years and above. The village has an estimated population of 2824. Method: A non experimental descriptive research design using qualitative approach was used. Sampling: Two types of sampling procedure were used, being simple random sampling and purposive sampling. Results: The study revealed that 85% of the respondents reported or suffered from the injuries due to high waters brought about by floods, 92% reported to have fallen sick or having a member of their family who was sick with conditions related to floods. Of all the respondents, 54% explained they heard of deaths occurring in a river either due to drowning or crocodile and hippopotamus attacks. Lastly, 8% of respondents reported they never heard of any injuries, illness or death due to the impacts of floods. Conclusion: It can thus be concluded that the river has an impact to the health of the community either before, during and after a flood event, activities may be undertaken by the population at risk, by policy makers and by emergency responders to reduce health risks. Proper planning aimed to reduce the harmful effects of flooding by limiting the impact of a flood on human health and economic infrastructure should be adopted. Key words: health, sepopa village, impact, Okavango river.
86

Reconstructing the levees : the politics of flooding in nineteenth-century Louisiana /

Poe, Cynthia R. January 1900 (has links)
Thesis (Ph.D.)--University of Wisconsin--Madison, 2006. / Includes bibliographical references (p. 265-291). Also available on the Internet.
87

Flash flooding across the southern Appalachian Mountains : an abbreviated climatology

Phillips, Anthony D. 21 July 2012 (has links)
From 1981 to 2010 flooding claimed an average of 92 lives each year in the United States. According to the National Oceanic and Atmospheric Administration National Weather Service, in 2010 the number of flood-related fatalities (103) was second only to heat (138). Flash flooding is especially dangerous as sudden, torrential downpours from thunderstorms can cause gullies, streams, and creeks to rise quickly and become an immediate risk to life and property. Across the southern Appalachian Mountains this threat is aggravated by steep terrain and the rapid accumulation of rainfall in narrow valleys and gorges. Severe storm reports were gathered from the National Climatic Data Center from 1996 to 2010. An emphasis was placed on flash flood events collected after the modernization of the National Weather Service in the mid-1990s when verification of storm reports became mandatory. Using a Geographic Information System, an abbreviated climatology of flash flood events was constructed to better understand the frequency and distribution of such events over the extent of the southern Appalachians. Additionally, forecasters and hydrologists provided insight on where flash floods occur most frequently across their County Warning Areas. In total, there were 4,938 flash flood reports across the southern Appalachian Mountains from 1996 to 2010. Of those reports there were 71 fatalities and 64 injuries, many of which occurred during the evening and overnight hours. Nearly 33 percent of all fatalities were associated with a vehicle and another 38 percent occurred when residents were swept away while traversing swollen creeks and streams. The information presented herein will assist meteorologists and hydrologists as well as those who would like to gain additional knowledge about flash flood climatology across the southern Appalachians. / Review of relevant literature -- Data and methodology -- Results, part I : an abbreviated climatology -- Results, part II : National Weather Service WFO discussions. / Department of Geography
88

Reconstructing the levees the politics of flooding in nineteenth-century Louisiana /

Poe, Cynthia R. January 1900 (has links)
Thesis (Ph.D.)--University of Wisconsin--Madison, 2006. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 265-291).
89

Exploring Spatiotemporal Patterns in Hazardous Hydrologic Events: Assessment, Communication, and Mitigation Through Geospatial Technologies

Afriyie, Emmanuel 01 May 2024 (has links) (PDF)
Tennessee has a long history of meteorological hazards that have caused property damage and loss of life. Given climate change and variability, it is imperative to look at trends to ascertain changes spatiotemporally. Space-time cubes, a novel geographic tool, were used to analyze historical heavy precipitation (1-, 2-, and 5-year returns), floods, and flash flood data in Tennessee counties to assess the trends, identify emerging hotspots/cold spots and display changes over space and time. For all return periods, trends analysis revealed that heavy precipitation events are increasing in several counties across the state, with middle Tennessee identified as a hotspot. While floods and flash flood event trends are mixed (with both increases and decreases) across the state counties, related property damages are increasing, especially in middle Tennessee. This study is an important step to understanding spatiotemporal trends and will be useful in federal, state, and county hazard mitigation planning.
90

Riskbegreppets ogreppbarhet : En studie av riskbegreppets rörliga aspekter och dess påverkan på Karlstad kommuns hantering av översvämningsrisker. / The notion of risk and its intangible features : A study of the different perspectives of risk management and its impact on Karlstad Municipality’s management of flood-risks.

Persson, Jens January 2016 (has links)
The purpose of this essay is to provide a deeper understanding of how the notion of risk and its intangible features affects the spatial planning of Karlstad Municipality with focus on how central actors (Karlstad Municipality and Länsstyrelsen Värmland) are handling the notion of flood-risks. This is interesting to study especially when considering building new living areas on ground that is troubled with floods. What becomes interesting to study is how the view on risk-management differs among actors. The methods used for conducting this research are document analysis and interviews which hopefully will bring a deeper understanding of how the notion of risk is being treated differently depending of which actor is being studied. In this study, a case-study was made on a planning-process of a new residential area located on flood-prone area. The result shows that both actors studied are not willing to take any risks when it comes to prognoses of climate change. On the other hand, for Länsstyrelsen there was a small doubt towards building on these kinds of areas. The difference in the view of risk seems to lie in which understanding we have of what we know. Länsstyrelsen seems to be skeptical to the trust in knowledge and technology that Karlstad Municipality seems to have. That view could be involuntary though, especially because of the lack of residential apartments along with the market ideals of building close to water. The problem is that they are building on attractive but yet risky areas, and to reduce these risks a flood guard has been built. The situation becomes a paradox where they want to have the cake and still eat it. This dilemma is very expensive and at the same the solutions made are not 100 % safe regarding the uncertainty of climate change. This paradox implies that risks are being created which later have to be dealt with. The central actors deal with the situation in the best way through trusting the technology and the prognoses that are provided today. / Syftet med uppsatsen är att ge en djupare förståelse för hur riskbegreppets ogreppbarhet påverkar Karlstads samhällsplanering med fokus på hur centrala aktörer (Karlstad kommun och Länsstyrelsen Värmland) förhåller sig till översvämningsrisker. Detta är intressant att undersöka med tanke på att det byggs nya bostadsområden på mark som är översvämningsdrabbat. Det som då blir intressant att undersöka i en sådan här fråga är hur synen på risk skiljer sig olika centrala aktörer emellan. Metoderna som använts som försök för att besvara dessa frågor är dokumentanalyser som tillsammans med intervjuer förväntas ge en djupare förståelse för hur synen på risk kan se olika ut beroende på vilken aktör som studeras. I detta fall gjordes en fallstudie på en enskild planprocess tillhörande ett område som i skrivande stund planeras byggas i ett riskfyllt område. Resultatet visade att båda parterna inte är villiga att ta några som helst risker när det kommer till de prognoser vi har idag. För Länsstyrelsens del fanns dock en grundläggande skepsis mot dessa typer av byggnationer. Skillnaden i synen på risk verkar ligga i förhållandet till det vi vet. Länsstyrelsen visade sig vara skeptisk till den tillit på teknik och kunskap som Karlstad kommun verkar ha. Problemet är att det byggs på ett eftertraktat område som innebär tydliga risker och för att minska dessa risker byggs ett översvämningsskydd. På så sätt blir det ett dilemma som är väldigt kostsamt och som till 100 % kanske inte ens går att lösa med tanke på osäkerheten i klimatförändringarna. Denna paradox innebär alltså att man bygger sig till risker som sedan måste hanteras. Situationen är dock som den är idag vilket gör att de centrala aktörer som spelar en roll i denna nyexploatering helt enkelt måste göra det bästa av situationen och förlita sig på den teknik och de prognoser som finns idag.

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