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  Partner: UNT Libraries
 Department: Department of Geography
 Collection: UNT Theses and Dissertations
Selecting Optimal Residential Locations Using Fuzzy GIS Modeling

Selecting Optimal Residential Locations Using Fuzzy GIS Modeling

Date: December 2006
Creator: Tang, Zongpei
Description: Integrating decision analytical techniques in geographic information systems (GIS) can help remove the two primary obstacles in spatial decision making: inaccessibility to required geographic data and difficulties in synthesizing various criteria. I developed a GIS model to assist people seeking optimal residential locations. Fuzzy set theory was used to codify criteria for each factor used in evaluating residential locations, and weighted linear combination (WLC) was employed to simulate users' preferences in decision making. Three examples were used to demonstrate the applications in the study area. The results from the examples were analyzed. The model and the ArcGIS Extension can be used in other geographic areas for residential location selection, or in other applications of spatial decision making.
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Shoreline Erosion at Mad Island Marsh Preserve, Matagorda County, Texas

Shoreline Erosion at Mad Island Marsh Preserve, Matagorda County, Texas

Date: August 2005
Creator: Mangham, Webster
Description: The Nature Conservancy of Texas (TNC) is concerned with the amount of shoreline erosion taking place at its Mad Island Marsh Preserve (MIMP), located in Matagorda Bay, Texas. The MIMP is a 7,100 acre nature preserve that borders the Gulf Intracoastal Waterway and is eroded by waves generated by barge traffic. TNC is concerned that erosion will shorten Mad Island Bayou which may increase the salinity of Mad Island Lake; with detrimental effects on lake and marsh habitats. This study uses GPS technology to map the current shoreline and GIS to determine ten year erosion rates (1995 - 2005). Results show that erosion is occurring at various rates along the shoreline as well as along the oxbow bend in Mad Island Bayou.
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Soil Characteristics Estimation and Its Application in Water Balance Dynamics

Soil Characteristics Estimation and Its Application in Water Balance Dynamics

Date: December 2008
Creator: Chen, Liping
Description: This thesis is a contribution to the work of the Texas Environmental Observatory (TEO), which provides environmental information from the Greenbelt Corridor (GBC) of the Elm Fork of the Trinity River. The motivation of this research is to analyze the short-term water dynamic of soil in response to the substantial rainfall events that occurred in North Texas in 2007. Data collected during that year by a TEO soil and weather station located at the GBC includes precipitation, and soil moisture levels at various depths. In addition to these field measurements there is soil texture data obtained from lab experiments. By comparing existing water dynamic models, water balance equations were selected for the study as they reflect the water movement of the soil without complicated interrelation between parameters. Estimations of water flow between soil layers, infiltration rate, runoff, evapotranspiration, water potential, hydraulic conductivity, and field capacity are all obtained by direct and indirect methods. The response of the soil at field scale to rainfall event is interpreted in form of flow and change of soil moisture at each layer. Additionally, the analysis demonstrates that the accuracy of soil characteristic measurement is the main factor that effect physical description. Suggestions for model ...
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Spatial Analysis of Hiv/aids Survival in Dallas and Harris Counties, Texas

Spatial Analysis of Hiv/aids Survival in Dallas and Harris Counties, Texas

Date: May 2012
Creator: Heald, Stephanie
Description: More Texans are living with HIV infection than ever before. in fact, there has been a 6% increase annually, since 2002. This trend is not a result of increased HIV/AIDS incidence, but rather improving life expectancy of those living with HIV. Due to significant advances in HIV/AIDS testing, prevention, and treatment, individuals with HIV are living longer than ever before. However, throughout the state, the life expectancy of a person infected with HIV/AIDS varies spatially. This study investigates and attempts to explain the spatial distribution of HIV/AIDS survival rates by examining neighborhood socioeconomic characteristics. the results suggest that, contrary to expectation, the lowest survival rates occur, not in extreme poverty areas, but rather in moderate SES areas. Too rich to qualify for free treatments, but not rich enough to afford purchasing such treatments, the middle income living with HIV infection are caught between the cracks. the results provide important input for targeting public health interventions to improve HIV/AIDS survival.
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Spatial Analysis of North Central Texas Traffic Fatalities 2001-2006

Spatial Analysis of North Central Texas Traffic Fatalities 2001-2006

Date: December 2010
Creator: Rafferty, Paula S.
Description: A traditional two dimensional (planar) statistical analysis was used to identify the clustering types of North Central Texas traffic fatalities occurring in 2001-2006. Over 3,700 crash locations clustered in ways that were unlike other researched regions. A two dimensional (x and y coordinates) space was manipulated to mimic a one dimensional network to identify the tightest clustering of fatalities in the nearly 400,000 crashes reported from state agencies from 2003-2006. The roadway design was found to significantly affect crash location. A one dimensional (linear) network analysis was then used to measure the statistically significant clustering of flow variables of after dark crashes and daylight crashes. Flow variables were determined to significantly affect crash location after dark. The linear and planar results were compared and the one dimensional, linear analysis was found to be more accurate because it did not over detect the clustering of events on a network.
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Spatial Analysis of Teen Births in North Central Texas

Spatial Analysis of Teen Births in North Central Texas

Date: December 2001
Creator: Donkor, Faustina Fosua
Description: The United States has the highest teen birth rate among western industrialized countries and the highest levels of pregnancy among adolescents (Alan Guttmacher Institute, 1994). While the rate of teen births is high throughout the country, considerable variations exist between and within regions. Texas is one of the 5 leading states with the highest teen birth rates to mothers less than 18 years of age. This research provides a detailed analysis of births to mothers aged between 10 and 19 years in North Central Texas counties. Due to the modifiable area unit problem and to provide a finer geographical scale of analysis, teen births in Dallas County zip codes were examined as a special case study. Statistical and Geographic Information System (GIS) analysis reveal that race/ethnicity, education and income are significant factors in teen births in the region. Single parent households and receipt of public assistance were not statistically significant. Suggestions for reducing vulnerability to teen births are presented.
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Spatial Patterns in Development Regulation: Tree Preservation Ordinances of the DFW Metropolitan Area

Spatial Patterns in Development Regulation: Tree Preservation Ordinances of the DFW Metropolitan Area

Date: August 2011
Creator: Cox, Carissa
Description: Land use regulations are typically established as a response to development activity. For effective growth management and habitat preservation, the opposite should occur. This study considers tree preservation ordinances of the Dallas-Fort Worth metropolitan area as a means of evaluating development regulation in a metropolitan context. It documents the impact urban cores have on regulations and policies throughout their region, demonstrating that the same urban-rural gradient used to describe physical components of our metropolitan areas also holds true in terms of policy formation. Although sophistication of land use regulation generally dissipates as one moves away from an urban core, native habitat is more pristine at the outer edges. To more effectively protect native habitat, regional preservation measures are recommended.
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A Spatial-Temporal Analysis of Retail Location and Clustering: A Case Study of Port Huron, MI

A Spatial-Temporal Analysis of Retail Location and Clustering: A Case Study of Port Huron, MI

Date: December 2007
Creator: Dickinson, Amie M.
Description: Retail geography is a field of study that is growing in significance and importance within the academic, business, economic, and governmental realms. This study's main focus is on the changing retail environment with regards to business location and function within a small Midwestern city. The research focuses on Port Huron, Michigan because of the growth and shift of the retail community within the city over the past twenty years. The study specifically examines the changing influence and roles of Port Huron's central business district and of Birchwood Mall a retail development opened on the urban area's north end in 1990. The study uses the chi-squared, ANOVA, and cross tabulation statistical tests to analyze the changing geography of retail functions in the city. These statistics are used along with relative entropy equations to distinguish areas of high diversification, changing area functions, and common locations for multiple retail types.
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A Spatially Explicit Environmental Health Surveillance Framework for Tick-Borne Diseases

A Spatially Explicit Environmental Health Surveillance Framework for Tick-Borne Diseases

Date: August 2010
Creator: AviƱa, Aldo
Description: In this paper, I will show how applying a spatially explicit context to an existing environmental health surveillance framework is vital for more complete surveillance of disease, and for disease prevention and intervention strategies. As a case study to test the viability of a spatial approach to this existing framework, the risk of human exposure to Lyme disease will be estimated. This spatially explicit framework divides the surveillance process into three components: hazard surveillance, exposure surveillance, and outcome surveillance. The components will be used both collectively and individually, to assess exposure risk to infected ticks. By utilizing all surveillance components, I will identify different areas of risk which would not have been identified otherwise. Hazard surveillance uses maximum entropy modeling and geographically weighted regression analysis to create spatial models that predict the geographic distribution of ticks in Texas. Exposure surveillance uses GIS methods to estimate the risk of human exposures to infected ticks, resulting in a map that predicts the likelihood of human-tick interactions across Texas, using LandScan 2008TM population data. Lastly, outcome surveillance uses kernel density estimation-based methods to describe and analyze the spatial patterns of tick-borne diseases, which results in a continuous map that reflects disease rates based ...
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Spatio-temporal Variation of Nitrate Levels in Groundwater in Texas, 1970 to 2010

Spatio-temporal Variation of Nitrate Levels in Groundwater in Texas, 1970 to 2010

Date: December 2012
Creator: Rice, Susan C.
Description: This study looks at spatial variation of groundwater nitrate in Texas and its fluctuations at 10 year increments using data from the Texas Water Development Board. While groundwater nitrate increased in the Ogallala and Seymour aquifers across the time period, the overall rate in Texas appears to be declining as time progresses. However, the available data is limited. Findings show that a much more targeted, knowledge based strategy for sampling would not only reduce the cost of water quality analysis but also reduce the risk of error in these analyses by providing a more realistic picture of the spatial variation of problem contaminants, thereby giving decision-makers a clearer picture on how best to handle the reduction and elimination of problem contaminants.
Contributing Partner: UNT Libraries