This thesis describes the present nature of one facet of some of the flood plain forest stands in Denton County, Texas. The specific purpose was to demonstrate the presence or absence of difference between the Celtis laevigata (commonly known as the hackberry, southern hackberry or sugarberry) populations in stands on Denton Creek and Elm Fork of the Trinity River.

Recently socio-hydrology models have been proposed to analyze the interplay of community risk-coping culture, flooding damage and economic growth. These models descriptively explain the feedbacks between socio-economic development and natural disasters such as floods. Complementary to these descriptive models, we develop a dynamic optimization model, where the inter-temporal decision of an economic agent interacts with the hydrological system. We assume a standard macro-economic growth model where agents derive utility from consumption and output depends on physical capital that can be accumulated through investment. To this framework we add the occurrence of flooding events which will destroy part of the capital. We identify two specific periodic long term solutions and denote them rich and poor economies. Whereas rich economies can afford to invest in flood defense and therefore avoid flood damage and develop high living standards, poor economies prefer consumption instead of investing in flood defense capital and end up facing flood damages every time the water level rises like e.g. the Mekong delta. Nevertheless, they manage to sustain at least a low level of physical capital. We identify optimal investment strategies and compare simulations with more frequent, more intense and stochastic high water level events.

Growing populations and industrialized agriculture practices have eradicated much of the United States wetlands along river floodplains. One program available for the restoration of floodplains is the Conservation Reserve Program (CRP). The current research explores the effects CRP land change has on flooding zones, utilizing Flood Modeller and HEC-RAS. Modelling in both one-dimensional and two-dimensional approaches were tested and analyzed for the same river reach. Flood Modeller is proven a viable tool for flood modeling within the United States when compared to HEC-RAS. Application of the software is used in the Nodaway River system located in the western halves of Iowa and Missouri, to model the effects of introducing new forest areas within the region. Flood stage during the conversion first decreases in the early years, before rising to produce greater heights. Flow velocities where CRP land is present are reduced for long-term scopes. Velocity reduction occurs as the Manning’s roughness values increase due to tree diameter and brush density. Flood zones become more widespread with the implementation of CRP. Comparing one-dimensional and two-dimensional flood mapping zones, the two-dimensional model shows less inundation. CRP land cover effects evolve over time, with the greatest impact appearing at the end of the contract.

No description available.

Dissertation Submitted for the degree of Master of Science in Geography at the University of the Witwatersrand FEBRUARY 08, 2016 / A flash flood is a flood which occurs within 6 hours from the start of a particular rainfall event. The ability to accurately evaluate and forecast flash floods could help in mitigating their harmful effects by helping communities plan their settlements outside of high risk areas and by providing information for the formulation and implementation of early warning systems. The overall aim of the study is to evaluate the use of RADAR data and hydrological models for flash flood evaluation and prediction. This is done by initialising both a lumped hydrological model (NAM) and a distributed hydrological model (MikeSHE) with both RADAR and raingauge derived precipitation estimates for the Jukskei river catchment located in Gauteng South Africa. The results of the model simulations are compared with each other and with actual streamflow data using various statistical techniques. The hydrometeorological characteristics of flash floods in the study catchment are also evaluated on a case by case basis. A fast response time and short duration are noted as the resounding characteristics of floods in the study catchment. All the model runs failed to correlate with streamflow (with any significant statistical certainty). The models also failed to significantly predict streamflow when using the pair sampled t-test. This highlights the difficulty in using rainfall estimates and hydrological models for discharge prediction. Although it is expected that the more advanced distributed model would fare better when predicting the variables associated with high flow events, it was only marginally better when simulating event timing. The lumped model did, however, fare better when correlating with stream flow, number of high flow events, peak flow, as well as total duration and volume / MT2016

Flash flood is among the most hazardous natural disasters, and it can cause severe damages to the environment and human life. Flash floods are mainly caused by intense rainfall and due to their rapid onset (within six hours of rainfall), very limited opportunity can be left for effective response. Understanding the socio-economic characteristics involving natural hazards potential, vulnerability, and resilience is necessary to address the damages to economy and casualties from extreme natural hazards. The vulnerability to flash floods is dependent on both biophysical and socio-economic factors. This study provides a comprehensive assessment of socio-economic vulnerability to flash flood alongside a novel framework for flash flood early warning system. A socio-economic vulnerability index was developed for each state and county in the Contiguous United States (CONUS). For this purpose, extensive ensembles of social and economic variables from US Census and the Bureau of Economic Analysis were assessed. The coincidence of socio-economic vulnerability and flash flood events were investigated to diagnose the critical and non-critical regions. In addition, a data-analytic approach is developed to assess the interaction between flash flood characteristics and the hydroclimatic variables, which is then applied as the foundation of the flash flood warning system. A novel framework based on the D-vine copula quantile regression algorithm is developed to detect the most significant hydroclimatic variables that describe the flash flood magnitude and duration as response variables and estimate the conditional quantiles of the flash flood characteristics. This study can help mitigate flash flood risks and improve recovery planning, and it can be useful for reducing flash flood impacts on vulnerable regions and population.

In 2011, both Major League Baseball (MLB) and the National Football League (NFL) saw the expiration of their collective bargaining agreements (CBAs) between the players’ unions and owners. Without an agreement in place, the two leagues would have been unable to play the next season. The CBAs established basic contract provisions, pensions and other benefits for players, and, most importantly, granted players the right to move between teams at their own discretion and outlined the manner in which they could do so. This process of changing teams was known as free agency.

Sammanfattning   Klimat- och sårbarhetsutredningen (SOU 2007:60) spår en framtid då Sveriges klimat till större del präglas av intensivt regn, och diskuterar konsekvenserna detta kommer innebära. Så väntas framtiden bli, men hur ser det ut idag? Syftet med uppsatsen är att kartlägga den samtida förekomsten av intensivt regn i Sverige och dess konsekvenser, i syfte att skapa en referenspunkt till diskussionerna om framtidens regnintensiva klimat och hur det kommer påverka samhället. Materialet studien bygger på har inhämtats från flera håll, men främst kommer det från SMHI, tidningsartiklar, räddningstjänster och kommuner. Sedan har en sammanställning gjorts där de identifierade händelserna analyserats kvantitativt och rumsligt. Studien är avgränsad till att endast inkludera händelser under sommarmånaderna juni, juli och augusti eftersom flest händelser av intensivt regn bedöms inträffa då. Resultatet visar stor geografisk spridning av inträffade regn, och liten kronologisk spridning. Alla landets län har drabbats men i norra och södra Norrland är förekomsten gles eller obefintlig, medan delar av mellersta Norrland, Svealand och Götaland påvisar flera koncentrerade områden. Kronologiskt sett inträffade den största delen av regnen i slutet av juli – minst antal drabbade juni. Konsekvenserna som rapporterats har till största del handlat om översvämmade bostäder och andra byggnader, samt erosionsskadade vägar och järnvägar. En konsekvensgruppering gjordes med fem konsekvensgrupper (KG) mellan 1 och 5, där KG 1 innehåller regn som inte fört med sig konsekvenser för människan och KG 5 väldigt omfattande och allvarliga konsekvenser för människan. 118 händelser hamnade i KG 1 och 21 i KG 4 – ingen uppnådde KG 5:s kriterier. En tendens visar att ju mer nederbörd som faller inom ett tätbebyggt område, i desto högre KG hamnar händelsen, även om det är svårt att säkert fastslå ett sådant orsakssamband utifrån det något ringa materialet. / Abstract   The Swedish investigation of climate and vulnerability (SOU 2007:60) predicts a future where the Swedish climate to a greater extent is characterized by heavy rain, and discusses the consequences this will cause. This is the future we believed to be expected, but how about today? The purpose with this paper is to map the present occurrence of heavy rain in Sweden and its consequences, to create a reference to include the discussions about climate change. The data the paper is based on were collected from several sources, but most parts come from The Swedish Meteorological and Hydrological Institute (SMHI), newspapers and Swedish rescue departments and municipalities. After data were compiled the identified episodes were analyzed both quantitatively and spatially. The study only includes episodes that occurred in June, July and August, since most of the heavy rains expected to occur during this period. The result shows a great spatial spreading of occurred episodes, and a minor chronological spreading. Every county in Sweden has been affected, but in the south and north of Northern and Central Sweden however the occurrences of heavy rain are sparse and sometimes absent. The regions with high concentration of episodes are in the middle of Northern and Central Sweden, South Central Sweden and Southern Sweden.  From a chronological view the major part of the identified episodes occurred in late July – June was the month with the fewest number of heavy rains. The consequences that have been found were divided into two categories; flood and erosion damages – the former mostly affected buildings, and the latter roads and railways. A categorization was done to subdivide the episodes grades of consequences into groups of different magnitudes. The levels were graded from 1-5, where 1 is the lowest grade. 118 episodes were placed in level 1 and only 21 in level 4 – zero episodes managed to fulfill the criteria of level 5. A tendency seen is that the more rain that falls within a densely area, the more consequences will occur, although it’s not possible to draw a safe conclusion based on the relatively sparse extent of data.

Poyang Lake is continuously shrinking and losing its function on account of deforestation and reclamation, causing water quality deterioration, frequent floods and ecological damages that impede economic growth. The research mainly analyzes the cause of Poyang Lake reclamation, its development, and pros and cons through historical literatures. The fact is found from 13th -19th centuries that farmers individually reclaimed the lake had caused external uneconomic problems. It not only negatively impacted local ecology but resulted in economic burden to the local government, who originally considered that the reclamation could bring in tax increases; however, the local financial resources are not sufficient to resolve existing problems. Under the contradictions among economic development, ecological protection, individual benefits and the overall security, the problems will continuously exist. The results of this research give an overall introduction concerning Poyang Lake in China. By illustrating the causes and impacts of reclamation and governances for lake, a relation among a specific political system, economic growth, ecological changes and policies can be demonstrated and underlying factors of flood disaster in China can be summarized.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on March 15, 2010.) Thesis advisor: Dr. Larry Brown. Includes bibliographical references.