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  Partner: UNT Libraries
 Department: Department of Geography
 Decade: 2010-2019
 Collection: UNT Theses and Dissertations
Analysis of Micro Enterprise Clusters in Developing Countries: A Case Study of Toluca, Mexico.
Businesses cluster to achieve agglomeration benefits. However, research in developing countries suggests that the economic environment limits small business’ propensity to benefit from agglomerations. The study examines the location, networking patterns, formal structures and owner characteristics of 1256 micro businesses from ten industries and thirteen sample areas in Toluca, Mexico. First, the thesis analyses whether clustering has a positive impact on the success rates of the surveyed enterprises, e.g. higher sales per employee. On an industry scale only Retail benefits from agglomerations economies. However, results of the neighborhood data show that specific areas benefit from urbanization economies. Overall, the study finds that businesses located within agglomerations, have higher levels of formalization, networking and professional training, hence constituting a more sophisticated base for economic development. Conclusions can be drawn for development policies and programs, arguing for a more differentiated approach of small business development depending on business location and cluster characteristics. digital.library.unt.edu/ark:/67531/metadc84200/
An Analysis of UNT Commuting Patterns
Academic institutions have recently organized to address their campus' greenhouse gas emissions. Along those lines, the University of North Texas (UNT) pledged to minimize the campus' environmental impact, and conducted a transportation survey in May 2009. The analyses confirm that commuting to campus was the second highest source (29%) of UNT's greenhouse gas emissions, following purchased electricity (48%). Students, faculty and staff drive over 89 million miles per year, 84% of which comes from students. Forty‐two percent of student driving trips originate in the primary and secondary core areas surrounding Denton, which are partially served by buses. However, because these core areas are in close proximity to the campus, they contribute only 8% of the total student driving distance. Beyond the Denton core, the inner periphery of Denton County contributes another 22% of driving mileage. Students living in the outer periphery (outside Denton County) contribute the remaining 70% of total driving distance, and carpooling is currently their only alternative. digital.library.unt.edu/ark:/67531/metadc28489/
Archaeological Proteomics: Method Development and Analysis of Protein-Ceramic Binding
The analysis of protein residues recovered from archaeological artifacts provides a unique opportunity to reveal new information about past societies. However, many scientists are currently unwilling to accept protein-based results due to problems in method development and a basic lack of agreement regarding the ability of proteins to bind to, and preserve within, artifacts such as pottery. In this paper, I address these challenges by conducting a two-phase experiment. First, I quantitatively evaluate the tendency of proteins to sorb to ceramic matrices by using total organic carbon analysis and spectrophotometric assays to analyze samples of experimentally cooked ceramic. I then test a series of solvent and physical parameters in order to develop an optimized method for extracting and preparing protein residues for identification via mass spectrometry. Results demonstrate that protein strongly sorbs to ceramic and is not easily removed, despite repeated washing, unless an appropriate extraction strategy is used. This has implications for the future of paleodietary, conservation ecology and forensic research in that it suggests the potential for recovery of aged or even ancient proteins from ceramic matrices. digital.library.unt.edu/ark:/67531/metadc28392/
Assessing the Role of Smaller Format Retailers on the Food Desert Landscape in Dallas, Texas
Many policy and business decisions regarding food deserts in the U.S. are based on the United States Department of Agriculture (USDA) definition of a food desert. This definition only includes large/national chain grocery retailers, based on the assumption that these major retailers are the only affordable sources of food contributing to balanced diets. As alternative distribution channels, including smaller stores, start to include groceries in their product offering, the need to consider the role of other businesses in the food retailing environment should be addressed. This thesis assesses the role of smaller format grocery retailers (small local grocers, convenience stores, gas stations, dollar stores, and drug stores) in shaping the food desert landscape in Dallas, Texas. The analysis evaluates the products offered in these stores, and then identifies the difference these stores make when included in the USDA analysis. This was done by collecting in-store data to determine the variety of products offered, the affordability of those products, and the overall healthfulness of the store. In addition, the gaps in supply and demand were identified in the USDA-defined food deserts in order to identify the impact any smaller format retailer may have. The findings suggest that, overall, smaller format retailers do offer a variety of products needed for a balanced diet. However, the products in these stores are mostly not affordable, and most stores offer more unhealthy foods, than unhealthy. Overall, results suggest dollar stores may play a role in alleviating the impact of food deserts. digital.library.unt.edu/ark:/67531/metadc271885/
Assessment of transportation emissions for ferrous scrap exports from the United States: Activity-based maritime emissions model and theoretical inland transportation model.
Industrial ecology is a field of study that encourages the use of closed-loop material cycles to achieve sustainability. Loop closing requires the movement of materials over space, and has long been practiced in the iron and steel industry. Iron and steel (ferrous) scrap generated in the U.S. is increasingly exported to countries in Asia, lengthening the transportation distance associated with closing the loop on the iron and steel life cycle. In order to understand the environmental cost of transporting this commodity, an activity-based maritime transportation model and a theoretical in-land transportation model are used to estimate emissions generated. Results indicate that 10.4 mmt of total emissions were generated, and emissions increased by 136 percent from 2004 to 2009. Increases in the amount of emissions generated are due to increases in the amount of scrap exported and distance it is transported. digital.library.unt.edu/ark:/67531/metadc103296/
Automated Treetop Detection and Tree Crown Identification Using Discrete-return Lidar Data
Accurate estimates of tree and forest biomass are essential for a wide range of applications. Automated treetop detection and tree crown discrimination using LiDAR data can greatly facilitate forest biomass estimation. Previous work has focused on homogenous or single-species forests, while few studies have focused on mixed forests. In this study, a new method for treetop detection is proposed in which the treetop is the cluster center of selected points rather than the highest point. Based on treetop detection, tree crowns are discriminated through comparison of three-dimensional shape signatures. The methods are first tested using simulated LiDAR point clouds for trees, and then applied to real LiDAR data from the Soquel Demonstration State Forest, California, USA. Results from both simulated and real LiDAR data show that the proposed method has great potential for effective detection of treetops and discrimination of tree crowns. digital.library.unt.edu/ark:/67531/metadc271858/
County Level Population Estimation Using Knowledge-Based Image Classification and Regression Models
This paper presents methods and results of county-level population estimation using Landsat Thematic Mapper (TM) images of Denton County and Collin County in Texas. Landsat TM images acquired in March 2000 were classified into residential and non-residential classes using maximum likelihood classification and knowledge-based classification methods. Accuracy assessment results from the classified image produced using knowledge-based classification and traditional supervised classification (maximum likelihood classification) methods suggest that knowledge-based classification is more effective than traditional supervised classification methods. Furthermore, using randomly selected samples of census block groups, ordinary least squares (OLS) and geographically weighted regression (GWR) models were created for total population estimation. The overall accuracy of the models is over 96% at the county level. The results also suggest that underestimation normally occurs in block groups with high population density, whereas overestimation occurs in block groups with low population density. digital.library.unt.edu/ark:/67531/metadc30498/
Examining the Role of Latitude and Differential Insolation in Asymmetrical Valley Development
Valley development through erosional processes typically tends to create symmetrical valleys. Over time, water cuts through the substrate to create valleys, gorges, and canyons for which the sides are the valley are evenly sloped. However, there are anomalies to this process. Asymmetrical valleys have been well-documented even in areas of uniform substrate or little tectonic uplift. One proposed explanation for the asymmetry of these valleys is differential insolation. This may lead to different microclimates from one slope to another which alter the rate and extent of erosion. Since the differences in received insolation vary with latitude (especially in streams that flow along an east/west axis), it follows that the degree of asymmetry should also vary with latitude if differential insolation is a primary driving factor in the development of these valleys. To evaluate if insolation plays a role in the development of asymmetrical valleys, this study examines variability in asymmetry across 447 valleys in nine study areas located at different latitudes. The degree of asymmetry for each valley was measured by using 30 meter resolution digital elevation models (DEMs) to determine the slope angle of each side of the valley. Asymmetry was measured by computing a ratio of the average slope angle for each side of the valley (larger value divided by smaller). If the resulting value is one, the valley is deemed symmetrical. As the value increases, the degree of asymmetry increases. This investigation found that contrary to expectations, valleys at lower latitudes tend to have a higher degree of asymmetry than those at higher latitudes, which suggests that differential insolation does not play a major role in the development of these valleys. Instead, this study found that high altitudes and low latitudes are more frequently associated with a higher degree of asymmetry. These unexpected findings open the door to new avenues of investigation into the causes of asymmetrical valley development. digital.library.unt.edu/ark:/67531/metadc283821/
The Expansion of a Retail Chain: An Analysis of Wal-Mart Locations in the United States
Retail geography is an expanding field that is becoming increasingly important within academia, the business environment, and the national and global economy. The focus of this study is to provide insight and additional understanding of the site selection processes employed by Wal-Mart in the United States. The research studies Wal-Mart from a national perspective and investigates the patterns of retail store expansion across the United States from 1990 to 2005. The study employs the use of a continuous Poisson model to check for significant clustering, and a single and multiple correlation analysis to identify the types of relationships that exist between retail stores and location. The results of the study make apparent several distinct patterns of retail store dispersion within the United States between the years 1990 to 2005. digital.library.unt.edu/ark:/67531/metadc68027/
An Exploration of the Ground Water Quality of the Trinity Aquifer Using Multivariate Statistical Techniques
The ground water quality of the Trinity Aquifer for wells sampled between 2000 and 2009 was examined using multivariate and spatial statistical techniques. A Kruskal-Wallis test revealed that all of the water quality parameters with the exception of nitrate vary with land use. A Spearman’s rho analysis illustrates that every water quality parameter with the exception of silica correlated with well depth. Factor analysis identified four factors contributable to hydrochemical processes, electrical conductivity, alkalinity, and the dissolution of parent rock material into the ground water. The cluster analysis generated seven clusters. A chi-squared analysis shows that Clusters 1, 2, 5, and 6 are reflective of the distribution of the entire dataset when looking specifically at land use categories. The nearest neighbor analysis revealed clustered, dispersed, and random patterns depending upon the entity being examined. The spatial autocorrelation technique used on the water quality parameters for the entire dataset identified that all of the parameters are random with the exception of pH which was found to be spatially clustered. The combination of the multivariate and spatial techniques together identified influences on the Trinity Aquifer including hydrochemical processes, agricultural activities, recharge, and land use. In addition, the techniques aided in identifying areas warranting future monitoring which are located in the western and southwestern parts of the aquifer. digital.library.unt.edu/ark:/67531/metadc84218/
Faunal Exploitation during the Depopulation of the Mesa Verde Region (A. D. 1300): A Case Study of Goodman Point Pueblo (5MT604)
This analysis of faunal remains from Goodman Point Pueblo (5MT604), a large village occupied just before the ancestral Puebloans permanently left southwestern Colorado at the end of the thirteenth century, explores the effect of dietary stress during abandonment in the Four Corners region. As archaeologists, we interpret what these former cultures were like and what resources they used through what they left behind. By specifically looking at faunal remains, or remains from food resources, environmental change and dietary stress can be assessed. Identifications of taxa identified at Goodman Point are made explicit via a systematic paleontology. This is followed by site-level taxonomic abundances and spatial analysis. Then, effects of technological innovations, environmental change, and sample quality are examined as alternate explanations of shifts in foraging efficiency, particularly related to animal hunting. Analyzing why and if the availability of faunal resources changes over time helps to clarify why the ancestral Puebloans left southwestern Colorado. digital.library.unt.edu/ark:/67531/metadc84216/
Finding Terroir in Southwest Iowa
Terroir combines the physical landscape of the vineyard with the grapevines and the methods and techniques used to produce wine from the grapes. This study used a GIS to identify the characteristics of the physical landscape in Pottawattamie, Mills, Montgomery, Fremont, and Page counties in southwestern Iowa. The components were combined in the GIS using a weighted linear index to identify areas suitable for vineyard development and to identify the general characteristics of the area. Vineyard owners were interviewed to help determine the weighting system to use in the GIS and to determine their perceptions of how the physical landscape impacts their vineyards, as well as to determine what grape varieties they plant in their vineyards and their decisions on making wine from these grapes. This information was collected to identify whether the vineyard owners had developed a sense of place for their vineyards and how this sense might aid them in the development of a terroir for their wines. The resulting perceptions about the individual wineries were then considered in conjunction with the results from the GIS modeling to understand how the physical landscape influences the concepts of sense of place and terroir in southwest Iowa. The physical landscape of southwest Iowa was fairly uniform, as were the grape varietals planted in the vineyards. This created a measure of similarity among the wineries, while individuality between wineries was then created by the wine-makers as they used different techniques to produce wine from the grapes. This allows each winery to develop a sense of place, yet be part of a larger sense of place that encompasses multiple wineries within the area. digital.library.unt.edu/ark:/67531/metadc283815/
Gentrification in Oklahoma City: Examining Urban Revitalization in Middle America
Access: Use of this item is restricted to the UNT Community.
Gentrification applies not only to the largest and oldest cities; it is a multi-scalar phenomenon playing out in smaller and less prominent settings as well. This study examines temporal changes in property values, demographic characteristics, and types of businesses in the central Oklahoma City area. A major urban revitalization project which began in 1993 created strong gentrification characteristics near the renewal's epicenter, the Bricktown entertainment district. Data suggest that several specific neighborhoods in the surrounding area exhibited rising property values, improving educational attainment rates, decreasing household sizes, and a shift toward cosmopolitan retail activity. While it is evident that Bricktown has been transformed, the socio-economic traits of surrounding neighborhoods have been altered by the ripple effects of urban renewal. digital.library.unt.edu/ark:/67531/metadc84266/
Geoarchaeological Analysis of Two New Test Pits at the Dmanisi Site, Republic of Georgia
This thesis presents the results of geoarchaeological investigations conducted at two new test pits, M11 and M12, at the paleoanthropological site of Dmanisi during the 2012 field season. This research is important for understanding the site formation processes occurring along the north-south axis of the Dmanisi site and how that affects the chronostratigraphic sequence and interpretation of archaeological materials here. With these excavations we can build a stronger interpretation for how broader areas of this site formed and changed both geologically and archaeologically. The geologic results of this study indicate that changes in sediment deposition and development episodes can affect interpretations of how long these sediments accumulated, how likely bones are to preserve, as well as how secondary gravel deposition can influence several archaeological interpretations. The archaeological results suggest that there could have been changes in occupation intensity between the stratum A and B phases although different rates of sediment deposition and surface stability could affect such artifact accumulations. In addition, during the stratum B phase there appears to be little change in artifact procurement behaviors and reduction characteristics by these hominins. The overall results of this research indicate that geologic factors should be addressed and cautions should be taken prior to making interpretations about archaeological assemblages. digital.library.unt.edu/ark:/67531/metadc271922/
A Geoarchaeological Investigation of Site Formation in the Animas River Valley at Aztec Ruins National Monument, NM
This paper presents an investigation of sedimentary deposition, soil formation, and pedoturbation in the Animas River Valley to determine the provenience of archaeological deposits in an open field at Aztec Ruins National Monument, NM outside of the Greathouse complex. Four stratigraphic pedounits correlated with active fan deposition have been proposed for the lower terrace in the project area with only one of these units retaining strong potential for buried archaeological deposits from the Anasazi late Pueblo II/Pueblo III period. The distal fan on the lower terrace and the Animas River floodplain appear to show poor potential for archaeological deposits either due to shallow sediment overburden with historic disturbance or alluvial activity during or after occupation. Based on these findings, four other zones of similar fan development have been identified throughout the Animas Valley and are recommended for subsurface testing during future cultural resource investigations. digital.library.unt.edu/ark:/67531/metadc30442/
Geography of Hiv Infection Among Adults Aged 50 Years and Older in Texas From 1999-2009
Twenty four percent of all HIV infections in the United States occur among adults aged 50 and older (mature adults), yet little is understood of the dynamics of HIV infection among this group in Texas. Data from 1999 to 2009 examined the relationship between HIV spatial and temporal patterns affecting socio-economic and demographic variables including poverty, gender, race/ethnicity and mode of exposure. Results revealed highest HIV infection rates among White homosexual men, Black males engaged in IV-drug use, Black female heterosexuals and minorities in poverty. Concentrations of HIV infection among mature adults were located primarily in urban centers of Houston and Dallas and indicated increasing HIV infection rates from 1999 to 2009. These results will assist future allocation of resources by zip code in urban areas for this understudied population. digital.library.unt.edu/ark:/67531/metadc149604/
Geologic and Lithic Analysis of the Red River Cache
The Red River Cache is an assemblage of 33 bifaces, found in Cooke County, along Cache Creek, a tributary to the Red River. Also found with the cache was a hearth which yielded charcoal for AMS dating which returned an age of 2770- 2710 Cal YBP placing the cache in the Late Archaic. The geologic investigation of Cache Creek established 3 Holocene allostratigraphic units that provide information depositional environments adjacent to the Red River. Lithic analysis explored the production of bifaces during the Late Archaic and compared the cache to regional records. Using both geologic and lithic analysis this thesis investigates the temporal and cultural context of the cache using a geoarchaeological approach. digital.library.unt.edu/ark:/67531/metadc67986/
Gis, Modeling And Human Civilization: The Birth Of Geo-social Engineering
Computer-based, mathematical models have significant value in describing the processes behind urban development and its inhabitants. The following research describes the theories and concepts behind modeling and offers insight into the potential future of the field. First, the research covers a brief history of applicable modeling strategies. This is followed by a summary of current popular approaches. The numerical background of geo-social engineering is developed through mathematical techniques. Geo-social engineering is the integration of modeling into the basic design human civilization. The mathematical models will be incorporated into a design of a computer program. From this, a possible geo-social model structure is presented and its architecture is described. digital.library.unt.edu/ark:/67531/metadc103362/
The Global Expansion of Transnational Retailers: A Case Study of the Localization Strategy of Costco in Taiwan
This research focuses on the global expansion of the transnational retail industry. Globalization is a phenomenon experienced by many industries in the present global economy. The global production network (GPN) framework can be used to explain and interpret the phenomenon of transnational firms' adaptation strategies. Due to market saturation in their home countries, retailers began to expand into East Asia in the 1980s. However, cultural differences and legislative limitations created barriers and restrictions for the transnational retailers making this transition. How do firms overcome these challenges? Through a case study of Costco in Taiwan, this research investigates the ways in which retailers adapt their strategies with regard to three concerns: site decisions, product mix selection, and supply network consolidation. The results shows that Costco opted for a strategy of lesser localization in all three domains. This research provides evidence to support this characterization along with examples of Costco's localization strategies via a case study and focuses on the issue of the balance between localization and standardization in the GPN framework. digital.library.unt.edu/ark:/67531/metadc33218/
The Impact Of Land Use And Land Cover Change On The Spatial Distribution Of Buruli Ulcer In Southwest Ghana
Buruli ulcer (BU) is an environmental bacterium caused by Mycobacterium ulcerans. Modes of transmission and hosts of the disease remain unknown. The purposes of this study are to explore the environmental factors that are possibly explain the spatial distribution of BU, to predict BU cases by using the environmental factors, and to investigate the impact of land use and land cover change on the BU distribution. The study area covers the southwest portion of Ghana, 74 districts in 6 regions. The results show that the highest endemic areas occur in the center and expand to the southern portion of the study area. Statistically, the incidence rates of BU are positively correlated to the percentage of forest cover and inversely correlated to the percentages of grassland, soil, and urban areas in the study area. That is, forest is the most important environmental risk factor in this study. Model from zero-inflated Poisson regression is used in this paper to explain the impact of each land use and land cover type on the spatial distribution of BU. The results confirm that the changes of land use and land cover affect the spatial distribution of BU in the study area. digital.library.unt.edu/ark:/67531/metadc103385/
Installation and Manufacturing of Photovoltaics: an Assessment Using California and New York
Renewable energy studies are becoming increasingly important as world energy demand rises and current energy sources are increasingly questioned. Solar photovoltaics (PV) are the focus of this study as a renewable industry still in its infancy. This research examines the geography of solar panel installation and manufacturing from 2007 to 2010 in California and New York. California is the larger of the two markets and has implemented more policy support; programs that appear to have increased the pace of installations, reduce the size of the subsidy, and help lower total costs. Similar trends are observable in New York. US based companies are still making solar panels, but foreign competitors, most notably from China and Mexico, are capturing an increasing share of the market. digital.library.unt.edu/ark:/67531/metadc149585/
An Investigation of the Relationship between HIV and Prison Facilities in Texas: The Geographic Variation and Vulnerable Neighborhood Characteristics
Previous research suggests that prisons may be fueling the spread of HIV infection in the general population. In 2005, the HIV rate was more than 2.5 times higher in US prison populations. Environmental factors in prisons such as illicit drug use and unprotected sexual activities can be conducive for HIV transmission. Because the vast majority of prison inmates are incarcerated for less than three years, transmission of HIV between prison inmates and members of the general population may occur at a high rate. The environment in which an individual lives and the entities that comprise it affect the health of that person. Thus the location of prisons within communities, as well as socio-demographic characteristics may influence the geography of HIV infection. HIV surveillance data, obtained from the Texas Department of State Health Services, were used to investigate the relationship between the location of prison units in Texas and HIV infection rates in the surrounding zip codes. The results suggest that HIV prevalence rates are higher among geographic areas in close proximity to a prison unit. With continued behavioral risks and low treatment adherence rates among individuals infected with HIV, there is a possibility of increased HIV prevalence. Vulnerable places, locations with higher HIV prevalence, should be targeted for resource allocation and HIV prevention and care service. This study illustrates the importance of spatial analysis of places vulnerable to increased HIV prevalence in creating more effective public health prevention strategies and interventions. digital.library.unt.edu/ark:/67531/metadc84234/
A Multiscalar Analysis of Buruli Ulcer in Ghana: Environmental and Behavioral Factors in Disease Prevalence
Buruli ulcer (BU), an infectious disease caused by Mycobacterium ulcerans, is the third most common mycobacterial disease after leprosy and tuberculosis and a WHO-defined neglected tropical disease. Despite years of research, the mode of transmission of BU remains unknown. This master’s thesis provides an integrated spatial analysis of disease dynamics in Ghana, West Africa, an area of comparatively high BU incidence. Within a case/matched control study design, environmental factors associated with BU infection and spatial behaviors are investigated to uncover possible links between individual daily activity spaces and terrains of risk across disturbed landscapes. This research relies upon archival and field-collected data and analyses conducted with geographical information systems (GIS). digital.library.unt.edu/ark:/67531/metadc115078/
Quantitative Comparison of Lidar Data and User-generated Three-dimensional Building Models From Google Building Maker
Volunteered geographic information (VGI) has received increased attention as a new paradigm for geographic information production, while light detection and ranging (LiDAR) data is widely applied to many fields. This study quantitatively compares LiDAR data and user-generated 3D building models created using Google Building Maker, and investigate the potential applications of the quantitative measures in support of rapid disaster damage assessment. User-generated 3D building models from Google Building Maker are compared with LiDAR-derived building models using 3D shape signatures. Eighteen 3D building models are created in Fremont, California using the Google Building Maker, and six shape functions (distance, angle, area, volume, slope, and aspect) are applied to the 18 LiDAR-derived building models and user-generated ones. A special case regarding the comparison between LiDAR data and building models with indented walls is also discussed. Based on the results, several conclusions are drawn, and limitations that require further study are also discussed. digital.library.unt.edu/ark:/67531/metadc149632/
The Role of Knowledge and Attitude in Residential Irrigation Efficiency
Residential irrigation efficiency is a long-term concern for any community that faces water supply stress. When ability to raise water prices is constrained, public education and conservation programs can produce reduced water usage. Understanding the factors behind residential irrigation efficiency allows the design of more effective conservation campaigns. Combining site-specific water budgets with usage data for four hundred homes in North Texas enables quantifying efficient irrigation behavior. A survey of homeowners tests for the presence of conservation-positive attitudes and the knowledge required to implement those attitudes. The influence of neighbors’ watering habits is investigated using spatial clustering tools. Findings are analyzed in the context of an attitude, knowledge, and habit model of conservation behavior. The presence of automatic irrigation systems, small irrigated areas, and having knowledge of the amount that one waters one’s lawn are found to contribute to more intensive irrigation. Mixed evidence for small-scale clustering in irrigation intensity is presented. digital.library.unt.edu/ark:/67531/metadc149645/
Spatial Analysis of Hiv/aids Survival in Dallas and Harris Counties, Texas
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. digital.library.unt.edu/ark:/67531/metadc115093/
Spatial Analysis of North Central Texas Traffic Fatalities 2001-2006
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. digital.library.unt.edu/ark:/67531/metadc33195/
Spatial Patterns in Development Regulation: Tree Preservation Ordinances of the DFW Metropolitan Area
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. digital.library.unt.edu/ark:/67531/metadc84194/
A Spatially Explicit Environmental Health Surveillance Framework for Tick-Borne Diseases
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 on population location. Data for this study was obtained from the Texas Department of Health Services and the University of North Texas Health Science Center. The data includes disease data on Lyme disease from 2004-2008, and the tick distribution estimates are based on field collections across Texas from 2004-2008. digital.library.unt.edu/ark:/67531/metadc30432/
Spatio-temporal Variation of Nitrate Levels in Groundwater in Texas, 1970 to 2010
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. digital.library.unt.edu/ark:/67531/metadc177244/
A Storm Water Runoff Investigation Using Gis and Remote Sensing
Environmental controls are becoming more and more expensive to implement, so environmental management is becoming more technologically advanced and efficient through the adoption of new techniques and models. This paper reviews the potential for storm water runoff for the city of Denton, Texas and with the main objective to perform storm water runoff analyses for three different land use datasets; each landuse dataset created with a different methodology. Also analyzed was the difference between two North Central Texas Council of Governments land use datasets and my own land use dataset as a part of evaluating new and emerging remote sensing techniques. The results showed that new remote sensing techniques can help to continually monitor changes within watersheds by providing more accurate data. digital.library.unt.edu/ark:/67531/metadc149613/
Using Geographic Information Systems for the Functional Assessment of Texas Coastal Prairie Freshwater Wetlands Around Galveston Bay
The objective of this study was to deploy a conceptual framework developed by M. Forbes using a geographic information system (GIS) approach to assess the functionality of wetlands in the Galveston Bay Area of Texas. This study utilized geospatial datasets which included National Wetland Inventory maps (NWI), LiDAR data, National Agriculture Imagery Program (NAIP) imagery and USGS National Land Cover data to assess the capacity of wetlands to store surface water and remove pollutants, including nitrogen, phosphorus, heavy metals, and organic compounds. The use of LiDAR to characterize the hydrogeomorphic characteristics of wetlands is a key contribution of this study to the science of wetland functional assessment. LiDAR data was used to estimate volumes for the 7,370 wetlands and delineate catchments for over 4,000 wetlands, located outside the 100-yr floodplain, within a 2,075 square mile area around Galveston Bay. Results from this study suggest that coastal prairie freshwater wetlands typically have a moderate capacity to store surface water from precipitation events, remove ammonium, and retain phosphorus and heavy metals and tend to have a high capacity for removing nitrate and retainremove organic compounds. The results serve as a valuable survey instrument for increasing the understanding of coastal prairie freshwater wetlands and support a cumulative estimate of the water quality and water storage functions on a regional scale. digital.library.unt.edu/ark:/67531/metadc28416/