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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.
21

Lone Wolves and Copycats: Assessing Policy and Infrastructure for Flood Hazard and Floodplain Management

Hamlin, Samantha L. 04 December 2018 (has links)
To mitigate flood hazard, which affects millions of people every year, increasing numbers of communities are developing green infrastructure policies to not only mitigate the hazard, but to meet other community policy objectives, as green infrastructure is often cited for the multiple benefits it confers. To support the implementation of policies that help communities meet their policy objectives, however, it is imperative to understand how policy is innovated and adopted. To do so, I applied the internal determinants and regional diffusion models, what I refer to as the lone wolf and copycat models. In policy, a lone wolf innovates a policy to meet a specific, internal objective; this objective may include economic, environmental, or social needs. A copycat evaluates the efficacy of a policy in other municipalities before adopting it for its own use. Because infrastructure is one of the primary routes of implementing flood hazard and floodplain management policies, I developed a framework that describes the relationship between these two models. In this framework, a community may rely more heavily on either gray or green infrastructure, while also being more of a lone wolf or copycat in the ways in which it adopts policy. Based on this framework, I analyzed four Oregon communities -- Eugene, Milton-Freewater, Prineville, and Sherwood -- that exemplify these different infrastructure and policy approaches. From this case study analysis, I developed several propositions to explain why each community pursued certain policies. I then expanded this research to floodplain administrators across the state, using a key informant questionnaire to capture the managerial and demographic characteristics that correlate with the adoption of green infrastructure in over 100 Oregon communities. I found that urbanization strongly correlated with the use of green infrastructure, as did a floodplain administrator having professional experience with flooding, being knowledgeable about flood mitigation infrastructure, and talking more frequently to other floodplain administrators. Finally, I use my research framework for an in-depth case study of the internal determinants model. I focus on a community in the Portland metropolitan area, Sherwood, and a program the community developed in the early 1990s to protect extensive areas of open space, greenways, and floodplains to preserve a unique community identity. In pursuing these objectives, Sherwood spearheaded the creation of the Tualatin River National Wildlife Refuge, the first urban wildlife refuge in the country.
22

Floodplain risk analysis using flood probability and annual exceedance probability maps /

Smemoe, Christopher M., January 2004 (has links) (PDF)
Thesis (Ph. D.)--Brigham Young University. Dept. of Civil and Environmental Engineering, 2004. / Includes bibliographical references (p. 223-229).
23

A watershed approach to decrease flooding of Pipe creek in Alexandria, Indiana

Zapf, Jeff January 1996 (has links)
This project explores one method of controlling flooding of Pipe Creek in Alexandria, Indiana. The method used is one of placing wetlands and grass filters within one subwatershed of Pipe Creek to reduce peak discharge and the time to peak discharge. A computer program called Sedimot II was used to determine the peak discharge for the Thurston Ditch subwatershed of Pipe Creek. Both 10 and 50 year 24 hour storms were studied. Following the construction of base line hydrographs for both storm events, four examples of wetland and grass filter placement were shown for the watershed. Hydrographs were then produced for all four alternatives for both 10 and 50 year storms. Recommendations were then made on how these examples could be used in the rest of the Pipe Creek watershed to further reduce the potential for flooding in Alexandria. / Department of Landscape Architecture
24

Woody corridor levee protection along the Missouri River mapping areas that can benefit: a thesis presented to the Department of Geology and Geography in candidacy for the degree of master of science /

Wood, Nathan Andrew. January 2008 (has links)
Thesis (M.S.)--Northwest Missouri State University, 2008. / The full text of the thesis is included in the pdf file. Title from title screen of full text.pdf file (viewed on December 17, 2008) Includes bibliographical references.
25

Examination, application, and evaluation of geomorphic principles and resulting water quality in Midwest agricultural streams and rivers

Powell, George Erick, January 2006 (has links)
Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 139-141).
26

USING 1D2D MODELING TO INFORM RESTORATION EFFORTS IN THE ATCHAFALAYA RIVER BASIN, LOUISIANA

Hayden-Lesmeister, Anne 01 August 2018 (has links)
The Atchafalaya River Basin (ARB) in Louisiana is the principal distributary of the Mississippi River, and it contains the largest contiguous area of baldcypress-water tupelo swamp forests in North America. After designation of the ARB as a federal floodway following the destructive 1927 Mississippi River (MR) flood, it was extensively modified to accommodate a substantial portion of the MR flow (~30%) to mitigate flooding in southern Louisiana. The resulting reach to system scale modifications for regional flood mitigation, navigation, and hydrocarbon extraction have substantially altered the lateral connectivity between the AR and its floodplain wetlands, threatening the ecological integrity of this globally-important ecosystem. Multiple stakeholder groups agree that restoring flow connectivity is essential to maintaining the basin’s water quality and forest health, and several flow-connectivity enhancement projects (hereafter, project elements) have been proposed by the Atchafalaya Basin Program’s Technical Advisory Group within the Flat Lake Water Management Unit (FLWMU) study area to increase lateral hydrologic connectivity within the management unit and beyond. Additionally, a new flow prescription to improve floodplain habitat has recently been suggested for the ARB. Flow into the ARB is now regulated through the Old River Control Structure (ORCS; operational in 1963), and represents the opportunity for large-scale flow experiments to enhance a multitude of ecosystem services that have been degraded due to anthropogenic alteration. For this study, I compiled existing datasets and constructed a 1D2D hydraulic model to evaluate: 1) if the suggested flow prescription would have the desired inundation impacts; 2) whether the proposed project elements would improve lateral connectivity in the FLWMU; and 3) whether recommended project elements would increase the area suitable for baldcypress recruitment in the study area. To examine the first two research questions above, I examined two scenarios – a baseline scenario to examine current conditions (no restoration projects), and a full-implementation scenario, where all proposed project elements that could be examined at the model resolution were implemented. Comparison of the modeling results for the baseline scenario to the suggested flow prescription goals suggests the overbank discharge and the extreme low-flow targets would have the desired impacts of inundating and drying out of the majority of the FLWMU, respectively. Proxy indicators of enhanced flow connectivity suggest that proposed projects will improve water quality, especially at intermediate to high flow conditions, when ~90% of the FLWMU experiences improved drainage as indicated by higher rates of water surface elevation decrease and lower overall system water volume. The stated objectives of the project elements recommended by the Technical Advisory Group are to improve connectivity and water quality, but another important and related restoration goal for stakeholders includes baldcypress restoration. To examine the third objective, I used a model-derived proxy indicator of habitat improvement (depth reduction) at two key discharges, along with other ecological suitability factors, to determine areas most likely to support baldcypress recruitment. Here, I compared baseline conditions to two alternative restoration scenarios – 1) a targeted implementation scenario where 22 project elements were implemented, and 2) the full-implementation scenario, where all projects that could be examined at the model resolution were implemented. Suitable habitat area for both natural and artificial baldcypress recruitment increased under intermediate flow conditions but remained unchanged for higher discharge conditions. For the intermediate discharge scenario, the full-implementation scenario results in a 2 km2 increase in the class considered most suitable for natural baldcypress regeneration within the calculated recruitment band, and a decrease of ~16 km2 in the areas considered least suitable for the entire FLWMU study area. Coupled with the connectivity results, which indicate that nutrient-rich river water will be exchanged between main channels and the backswamp at a greater range of flows, it appears that project implementation alone will benefit baldcypress recruitment, especially artificial regeneration efforts. However, full project implementation coupled with large-scale flow modifications at ORCS would likely provide maximum benefit for baldcypress restoration efforts that seek to increase the area supportive of natural baldcypress regeneration.
27

Using Genetic Algorithms to Calculate Floodway Stations With HEC-RAS

Yu, Lu January 2015 (has links)
No description available.
28

Comparison of Neighborhood Demographics and Post-Buyout Land Use Development in Harris County, Texas, USA

Niazi, Sumaira 07 1900 (has links)
Recent research suggests that race and ethnicity influence post-buyout land management in Harris County, Texas, yet lacked systematic empirical evidence to fully understand the relationship between management and demographics. To address this gap, this study analyzes post-buyout land use management practices and compares them with the socio-economic characteristics of the adjacent neighborhood at the block level in Harris County, Texas, an area with a long buyout history. I first identified post-buyout land use management practices in Harris County through county records and photo documentation of approximately 2000 buyout sites through fieldwork from 2017-2022. Second, using Ode and colleagues' framework for identifying visual characteristics on the landscape, I developed an index and evaluated post-buyout land use management practices for aesthetics, utility, and function. Finally, I spatially analyzed the socio-demographic composition of buyout neighborhoods using U.S. Census American Community Survey 5-year data (2017-2021) and compared it with post-buyout land use management practices in ArcGIS. From this spatial analysis, I identified differences in post-buyout land management that homeownership status, race, and ethnicity affected post-buyout land management. Most buyout properties in Harris County are managed as mowed, vacant lots regardless of socio-demographics; however, litter and debris were more prominent in predominantly Black neighborhoods. Of note, higher utility land uses were more frequent in predominantly white neighborhoods, but buyout sites developed into parks were located in lower-income and predominantly Hispanic areas suggesting variance in land use by socio-demographics.
29

Some new approaches to measuring willingness to pay: a case study of flood risk reduction in Roanoke, Virginia

Dietz, Brian C. 23 December 2009 (has links)
Benefits from a flood control project that accrue to a landowner are defined as the amount the landowner is willing to pay for the reduction in flood risk. The primary method utilized by the U.S. Army Corps of Engineers to estimate a residential landowner's benefits is the property damages avoided method. Only under a set of restrictive assumptions will this method accurately estimate landowner willingness to pay. Therefore, several alternative techniques, such as the hedonic price method, are approved for use by the Corps but it is not known how they compare. The purpose of this study is to examine the benefit measures from the property damages avoided and hedonic price methods and two new measures, restricted willingness to pay (RWTP) and restricted willingness to accept (RWTA). The measures RWTP and RWTA are biased estimates of willingness to pay (WTP) and willingness to accept (WTA) where the direction of the bias is known. In addition, the methods that calculate these measures, the RWTP and RWTA methods, do not require data on income or an aggregator for the prices of all goods not in the analysis. Benefit estimates from the hedonic price and RWTP methods provide upper and lower bounds on WTP for non-marginal reductions in flood risk and converge for marginal reductions. / Master of Science
30

A Data Fusion Framework for Floodplain Analysis using GIS and Remotely Sensed Data

Necsoiu, Dorel Marius 08 1900 (has links)
Throughout history floods have been part of the human experience. They are recurring phenomena that form a necessary and enduring feature of all river basin and lowland coastal systems. In an average year, they benefit millions of people who depend on them. In the more developed countries, major floods can be the largest cause of economic losses from natural disasters, and are also a major cause of disaster-related deaths in the less developed countries. Flood disaster mitigation research was conducted to determine how remotely sensed data can effectively be used to produce accurate flood plain maps (FPMs), and to identify/quantify the sources of error associated with such data. Differences were analyzed between flood maps produced by an automated remote sensing analysis tailored to the available satellite remote sensing datasets (rFPM), the 100-year flooded areas "predicted" by the Flood Insurance Rate Maps, and FPMs based on DEM and hydrological data (aFPM). Landuse/landcover was also examined to determine its influence on rFPM errors. These errors were identified and the results were integrated in a GIS to minimize landuse / landcover effects. Two substantial flood events were analyzed. These events were selected because of their similar characteristics (i.e., the existence of FIRM or Q3 data; flood data which included flood peaks, rating curves, and flood profiles; and DEM and remote sensing imagery.) Automatic feature extraction was determined to be an important component for successful flood analysis. A process network, in conjunction with domain specific information, was used to map raw remotely sensed data onto a representation that is more compatible with a GIS data model. From a practical point of view, rFPM provides a way to automatically match existing data models to the type of remote sensing data available for each event under investigation. Overall, results showed how remote sensing could contribute to the complex problem of flood management by providing an efficient way to revise the National Flood Insurance Program maps.

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