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.

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.

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.

Thesis (Ph.D.)--University of Wisconsin--Madison, 2006. / Includes bibliographical references (p. 265-291). Also available on the Internet.

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

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).

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.

Riparian areas are valuable resources, particularly in semi-arid areas where water is usually scarce and rapid streamflow responses to runoff are common. Only recently has the importance of in-channel recharge during high streamflow periods ("floods") been recognized in rivers with gaining and losing reaches where recharge processes and flowpaths can be very complex. This dissertation builds upon this recent work by investigating how three factors influence how riparian systems respond to floods over a range of temporal and spatial scales. First, the impact of differences in local hydrogeologic forcings are investigated at the seasonal and 50 meter-reach scales. Second, the significance of flood event size and duration is studied at the multi-year and river (~50 Km) scale. Third, an underlying mechanism behind how changes in bed sediment composition can influence stream-aquifer interactions at the event- and point-scales is developed. Major findings of this work include observations along the Upper San Pedro River of seasonal floodwater storage below moderately gaining reaches and longer-term storage below losing reaches (seasonal to multi-year depending on the nature of the riparian groundwater flow system). The longest and largest floods (with respect to flow volume) dominate floodwater recharge in the Bill Williams River and an apparent flood size and duration threshold exists. This threshold must be met or exceeded in order for individual events to induce observable amounts of recharge that can then influence the amount and composition of later streamflow. This threshold agrees with the process presented here involving preferential mobilization and deposition of fine bed sediment particles--which dictate hydraulic conductivity--during each event that would lead to disproportionately more recharge during large floods. Forecasts of increased precipitation intensity and decreased annual precipitation in some regions, including the southwestern United States, due to changes in the earth's climate are likely to make floods a more important driver of riparian hydrologic processes. Consequently, the work presented here and other process-based studies of how floods influence riparian hydrology and water quality will be useful in making well-informed decisions regarding riparian preservation, management and restoration as human demands and the global climate change in the future.

In South Africa, January 2011 was characterised by above average rainfall which resulted in many provinces being flooded. On the 17th of January 2011, the government of South Africa declared the City of Tshwane a National Disaster Area. It is in the city of Tshwane where a hotel was flooded causing great damage and disruption to the lives of the hotel workers. Given the lack of existing research focusing on the social dimensions of natural disasters, this provided an opportunity to study the social impact of the flood on the community of hotel workers at a Pretoria hotel. Four sub-aims were set for the study, which involved an exploration of the strengths that were exhibited, discovered or developed as a result of the flood; investigating the subjective experiences in relation to the flood; exploring the interactional patterns and relationships of the hotel workers; as well as investigating how the leadership of the hotel impacted on the manner in which the hotel workers dealt with the flood. A qualitative methodology, guided by a social constructivist epistemology was adopted as basis for the study. Data was gathered by means of individual semi-structured interviews, semi-structured questionnaires, and a focus group interview with a number of employees at the hotel. The data was subjected to qualitative content and grounded theoretical analysis. Five main themes emerged from the analysis, which include: Emotional responses, which included negative emotions such as shock, fear, frustration and anger, as well as positive emotions such as happiness and appreciation; a variety of interactional patterns and relationships; increased cohesiveness; enhanced leadership, and the development of group resilience. / MA, Medical Sociology, North-West University, Vaal Triangle Campus, 2012

The study is a contextual analysis of flood victimization. Victimization is defined as the social, psychological, and physiological aftermath experienced by victims of a disaster. Disaster researchers concentrate on the victims' characteristics to explain the varying degrees of their victimization, providing only ambiguous results. Theorists such as Kreps, Wildavsky, and Douglas contend that the outcomes of disasters are contingent upon social structure. This analysis treats victimization as one such outcome. The condition and behavior of individuals can be explained by the presence of disaster and the conditions of social organization. A model explains victimization based on individual's attributes (individual resources), his social environment, and the disaster characteristics. This study uses the 1984 Mingo Creek Flood Victims Survey data to test the model. The data contain information measuring victimization. The survey data are linked with 1980 Census tract data. The tract data provide indicators of the social networks. This tract information, the contextual variables, taps the social conditions, including poverty, unemployment, geographic mobility, and family patterns. This study uses factor analysis to identify the dimensions of victimization. Regression tests the relationship between the contextual variables, the individual resource variables, the disaster characteristic variables, and victimization. The results of the analysis show that victimization is multidimensional with different types of variables being significant predictors for each dimension of victimization, one variable indicating the intensity of the disaster, the dollar value of damage victims experienced, is found to be a significant predictor of the psychological, physiological, and social disruption aspects of victimization. Variables measuring the family and unemployment patterns in the victims' census tract are significant predictors of the psychological and social disruption aspect of victimization. The findings provide general support for the proposed model of victimization. However, victimization is multidimensional with each dimension having a unique set of predictors. Based on the findings, this study suggests that future research focus on measurement and conceptualization of the characteristics of disasters and the victims' social environment.