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Assessing the Potential Effects of Climate Variability on Reservoir Water Volume in North-Central Texas Using GIS and Models: A Case Study of Ray Roberts Lake.

Description: Assessing the impact of climate variability on water resources is one of the difficult tasks in planning the future growth of North-Central Texas. This study defined twelve extreme climate scenarios. Data from each scenario was input to a hydrological model (HEC-HMS) to calculate watershed runoff to Lake Ray Roberts. Model parameters are determined using Geographic Information System (GIS). The water balance was calculated for current and future water demand and resulting change in the volume and level of this reservoir. The results indicate certain climate scenarios decrease in volume. Thus, local governments should plan alternative water management strategies during droughts.
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Date: December 2005
Creator: Osei-Adjei, Peter

Assessment of Sediment Runoff from Natural Gas Well Development Sites.

Description: Storm water sediment runoff from disturbed landscapes has the potential to impair aquatic environments. Small construction sites of 1-5 acres in the United States are currently regulated by the United States Environmental Protection Agency to minimize storm water runoff damages to the environment. Gas well construction sites are similar to other construction sites in how the landscape is altered, but are not similarly regulated. This study identified sediment runoff from gas well development sites by collecting it in traps and weirs, and by measuring sediment debris lobes. Sediment primarily consisted of silt and clay sized particles. Sediments from two gas well sites formed five debris lobes that ranged in size from 325 to 3,290 square feet. Sediment loadings estimated from the debris lobes averaged 57.1 tons per year/acre. Future studies should focus on further quantification of sediment movement off of gas well sites and identify effective erosion control methods.
Date: May 2007
Creator: Havens, David Loran

A Comparative Analysis of Diseases Associated with Mining and Non-Mining Communities: A Case Study of Obusai and Asankrangwa, Ghana

Description: Disease prevalence varies with geographic location. This research pursues a medical geographic perspective and examines the spatial variations in disease patterns between Obuasi, a gold mining town and Asankrangwa, a non gold mining town in Ghana, West Africa. Political ecology/economy and the human ecology frameworks are used to explain the prevalence of diseases. Mining alters the environment and allows disease causing pathogens and vectors to survive more freely than in other similar environments. Certain diseases such as upper respiratory tract infections, ear infections, sexually transmitted diseases such as HIV/AIDS and syphilis, certain skin diseases and rheumatism and joint pains may have a higher prevalence in Obuasi when compared to Asankrangwa due to the mining in Obuasi.
Date: August 2005
Creator: Reddy, Sumanth G.

Comparison of IKONOS Derived Vegetation Index and LiDAR Derived Canopy Height Model for Grassland Management.

Description: Forest encroachment is understood to be the main reason for prairie grassland decline across the United States. In Texas and Oklahoma, juniper has been highlighted as particularly opportunistic. This study assesses the usefulness of three remote sensing techniques to aid in locating the areas of juniper encroachment for the LBJ Grasslands in Decatur, Texas. An object based classification was performed in eCognition and final accuracy assessments placed the overall accuracy at 94%, a significant improvement over traditional pixel based methods. Image biomass was estimated using normalized difference vegetation index (NDVI) for 1 meter resolution IKONOS winter images. A high correlation between the sum of NDVI for tree objects and field tree biomass was determined where R = 0.72, suggesting NDVI sum of a tree area is plausible. However, issues with NDVI saturation and regression produced unrealistically high biomass estimates for large NDVI. Canopy height model (CHM) derived from 3-5m LiDAR data did not perform as well. LiDAR typically used for digital elevation model (DEM) production was acquired for the CHM and produced correlations of R = 0.26. This suggests an inability for this particular dataset to identify juniper trees. When points that registered a tree height where correlated with field values, an R = 0.5 was found, suggesting denser point spacing would be necessary for this type of LiDAR data. Further refining of the methods used in this study could yield such information as the amount of juniper tree for a given location, fuel loads for prescribed burns and better information for the best approach to remove the juniper and ultimately management juniper encroachment into grasslands.
Date: December 2009
Creator: Parker, Gary

Determining the Suitability of Functional Landscapes and Wildlife Corridors Utilizing Conservation GIS Methods in Denton County, Texas.

Description: Denton County's unique cultural and natural landscape has undergone dramatic transformations during the past two centuries due to agricultural, urban and suburban processes which accelerated the loss and removal of native habitat and wildlife. This research sought out to identify the remaining natural areas which retain their natural features and support wildlife. Research methodology included fundamental principles of Conservation Planning, Geographical Information Systems, and Habitat Evaluation Procedures for identifying remnant functional landscapes and wildlife corridors. The final results suggest that Denton County's rural landscape retains the functional properties and elements suitable for habitat conservation and wildlife corridors, while also pointing to the fundamental obstacles to conservation posed by continued growth and private landownership.
Date: August 2007
Creator: Sales, Joshua

Developing a Wildlife Tracking Extension for ArcGIS

Description: Wildlife tracking is an essential task to gain better understanding of the migration pattern and use of space of the wildlife. Advances in computer technology and global positioning systems (GPS) have lowered costs, reduced processing time, and improved accuracy for tracking wild animals. In this thesis, a wildlife tracking extension is developed for ArcGIS 9.x, which allows biologists and ecologists to effectively track, visualize and analyze the movement patterns of wild animals. The extension has four major components: (1) data import; (2) tracking; (3) spatial and temporal analysis; and (4) data export. Compared with existing software tools for wildlife tracking, the major features of the extension include: (1) wildlife tracking capabilities using a dynamic data layer supported by a file geodatabase with 1 TB storage limit; (2) spatial clustering of wildlife locations; (3) lacunarity analysis of one-dimensional individual animal trajectories and two-dimensional animal locations for better understanding of animal movement patterns; and (4) herds evolvement modeling and graphic representation. The application of the extension is demonstrated using simulated data, test data collected by a GPS collar, and a real dataset collected by ARGOS satellite telemetry for albatrosses in the Pacific Ocean.
Date: May 2009
Creator: Chen, Cai

Differential use of space: An analysis of the Aubrey Clovis site.

Description: The Aubrey Clovis site is one of the oldest late-Pleistocene sites in North America, dated to ~11,550 B.P., and contains two camps with a range of lithic debitage, numerous hearths, and excellent faunal preservation. Couched in rules of classification, a series of artifact distributions are analyzed with qualitative and quantitative techniques, including maps produced in a geographic information system (GIS) and tests of artifact associations using correlation statistics. Theoretical and methodological protocols are promoted to improve spatial analysis in archaeology. The results support the short-term occupation interpretation and expose the differential patterning among bone, stone, and raw materials distributions. The spatial structure and diverse content of the site challenge models of Clovis-age people as strictly big game hunters.
Date: August 2005
Creator: Witt, Benjamin A.

Distribution and Probable Sources of Nitrate in the Seymour Aquifer, North Central Texas, USA

Description: This study utilized GIS and statistical methods to map the spatial variability of nitrate and related groundwater constituents in 30 counties above the Seymour Aquifer, analyze temporal patterns of nitrate pollution, identify probable sources of pollution, and recommend water development strategies to minimize exposure to nitrate and reduce future aquifer contamination. Nitrate concentrations in excess of 44 mg/L (US EPA limit) were commonly observed in the Seymour Aquifer region, especially in the central agricultural belt. Data indicated that this is an ongoing problem in the Seymour Aquifer and that agricultural activity and rural septic systems are the likely sources of the nitrate. Inconclusive results emphasized the need for a more comprehensive spatial and temporal water quality monitoring.
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Date: May 2001
Creator: Hillin, Clifford K.

An environmental justice assessment of the light rail expansion in Denton County, Texas.

Description: This study analyzes the proposed passenger rail line expansion along US Interstate Highway 35 in Denton County, Texas. A multi-dimensional approach was used to investigate potential environmental justice (EJ) consequences from the expansion of the transportation corridor. This study used empirical and historical evidence to identify and prioritize sites for potential EJ concerns. Citizen participation in the decision making process was also evaluated. The findings of this research suggest that the southeast Denton community has the highest potential for environmental justice concerns. This study concludes by offering suggestions for an effective public participation process. These include the incorporation of a community's local history into an environmental justice assessment, and tailoring the public planning process to the demographics and culture of the residents.
Date: August 2007
Creator: Moynihan, Colleen T.

Estimating Buruli Ulcer Prevalence in Southwestern Ghana

Description: Mycobacterium ulcerans is sweeping across sub-Saharan Africa, but little is known about the mode of transmission and its natural reservoirs. Since the only effective treatment is excision of the infection and surrounding tissue, early diagnosis and treatment is the only way to reduce the havoc associated with Buruli ulcer. Using data from a national case search survey conducted in Ghana during 2000 and suspected risk factors this study tests the hypothesized factors and probes the challenges of developing a spatial epidemiological regression model to explain Buruli ulcer prevalence in the southwestern region of Ghana representing 42 districts. Results suggest that prevalence is directly related to the degree of land cover classified as soil, elevation differential, and percent rural population of the area.
Date: August 2007
Creator: Denton, Curtis James

FACET Simulation in the Imataca Forest Reserve, Venezuela: Permanent Plot Data and Spatial Analysis

Description: Tree diameter data from 29 years of observations in six permanent plots was used to calculate the growth rate parameter of the FACET gap model for 39 species in the Imataca forests in Venezuela. The compound topographic index was used as a measure of differential soil water conditions and was calculated using geographic information systems. Growth rate values and topographic conditions typical of hill and valley were input to FACET to simulate dynamics at the species level and by ecological and functional groups. Species shade-tolerance led to expected successional patterns. Drought-tolerant/saturation-intolerant species grew in the hills whereas drought-intolerant/saturation-tolerant species occurred in the valleys. The results help to understand forest composition in the future and provide guidance to forest management practices.
Date: May 2006
Creator: Figuera, Dilcia

Geography of Tuberculosis in the Greater Accra Region of Ghana

Description: In Ghana, spatial patterns of TB vary for different regions and variations may occur within the same region. This study examines TB distribution in the Greater Accra Region of Ghana using Geographic Information Systems (GIS). Behavioral, cultural and economic variables associated with TB morbidity are examined. From January 1998 to June 1999, data obtained from the Ghana Ministry of Health revealed that, men had a higher TB rate than women, TB was common among the age groups 20-29 and 30-39, and the average TB rate of 67.7 per 100, 000 population in the Greater Accra Region was higher than the national average (58.6 per 100,000 population). Using the human ecology model, this study attempts to explain the spatial distribution of the disease.
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Date: May 2001
Creator: Donkor, Kweku

The Geologic and Archaeological History of the Dickie Carr Site 41PR26

Description: This thesis is an analysis and synthesis of the geologic and archaeological history of the Dickie Carr site, 41PR26, on Mill Creek in north central Texas. Included are analyses of the stratigraphy, sedimentary environments, and soils of the locality. A regional comparison is made with respect to the Late Quaternary geology of the upper Trinity River basin, Texas to interpret the geologic data. Two stratigraphic units were identified that record the Pleistocene-Holocene transition. The buried lower unit is comprised of terrace, floodplain, and channel deposits with extensive pedogenesis. The unit is Late Pleistocene in age and contains the remains of Mammuthus columbi. The upper stratigraphic unit is comprised of terrace and floodplain sediments with well-expressed pedogenesis. The unit is Early Holocene in age with Late Paleoindian and Late Archaic occupations. The archaeological components are compared and contrasted with documented sites from the Elm and East Forks of the Trinity River. The occupations are examined in a geoarchaeological context. The Late Paleoindian occupation is post-depositional and located in terrace deposits. The Late Archaic occupation is syndepositional and located in floodplain deposits.
Date: May 2007
Creator: Byers, Johnny A.

GIS application in emergency management of terrorism events on the University of North Texas campus.

Description: This thesis presents a Web-based geographic information system (GIS) application for campus emergency management that allows users to visualize, integrate, and analyze student population, facilities, and hazard data for efficient emergency management of University of North Texas before, during, and after a terrorism event. End-users can locate and search the source area of an event on a digital map from the ArcIMS-based Website. The website displays corresponding population information and attributes of impacted facilities in real time. School officials and first responders including police, firefighters and medical personnel can promptly plan the appropriate rescue and response procedures according to the displayed results. Finally, the thesis outlines the limitations of Web-based GIS in the arena of campus emergency management.
Date: August 2008
Creator: Tsang, Yuenting

GIS Modeling of Wetlands Elevation Change in Response to Projected Sea Level Rise, Trinity Bay, Texas

Description: This study is a test of a methodology to predict changes in elevation and shoreline position of coastal wetlands in Trinity Bay, Texas, in response to projected sea level rise. The study combines numerical modeling and a geographic information system. A smoothing technique is used on a United States Geographical Survey (USGS) digital elevation model to obtain elevation profiles that more accurately represent the gently sloping wetlands surface. The numerical model estimates the expected elevation change by raster cell based on input parameters of predicted sea level rise, mineral and organic sedimentation rates, and sediment autocompaction rates. A GIS is used to display predicted elevation changes and changes in shoreline position as a result of four projected sea level rise scenarios over the next 100 years. Results demonstrate that this numerical model and methodology are promising as a technique of modeling predicted elevation change and shoreline migration in wetlands. The approach has potential utility in coastal management applications.
Date: December 2005
Creator: Lee, Erica Anne

High Resolution Satellite Images and LiDAR Data for Small-Area Building Extraction and Population Estimation

Description: Population estimation in inter-censual years has many important applications. In this research, high-resolution pan-sharpened IKONOS image, LiDAR data, and parcel data are used to estimate small-area population in the eastern part of the city of Denton, Texas. Residential buildings are extracted through object-based classification techniques supported by shape indices and spectral signatures. Three population indicators -building count, building volume and building area at block level are derived using spatial joining and zonal statistics in GIS. Linear regression and geographically weighted regression (GWR) models generated using the three variables and the census data are used to estimate population at the census block level. The maximum total estimation accuracy that can be attained by the models is 94.21%. Accuracy assessments suggest that the GWR models outperformed linear regression models due to their better handling of spatial heterogeneity. Models generated from building volume and area gave better results. The models have lower accuracy in both densely populated census blocks and sparsely populated census blocks, which could be partly attributed to the lower accuracy of the LiDAR data used.
Date: December 2009
Creator: Ramesh, Sathya

Hydrological Impacts of Urbanization: White Rock Creek, Dallas Texas

Description: This research project concerns changes in hydrology resulting from urbanization of the upper sub-basin of the White Rock Creek Watershed in Collin and Dallas Counties, Texas. The objectives of this study are: to calculate the percent watershed urbanized for the period of 1961 through 1968 and the period of 2000 through 2005; to derive a 1960s average unit hydrograph and a 2000s average unit hydrograph; and, to use the two averaged hydrographs to develop a range of hypothetical storm scenarios to evaluate how the storm response of the watershed has changed between these two periods. Results of this study show that stormflow occurs under lower intensity precipitation in the post-urbanized period and that stormflow peaks and volumes are substantially larger compared to the pre-urbanized period. It is concluded that changes in watershed surface conditions resulting from urbanization have lowered the precipitation-intensity threshold that must be surpassed before storm run-off is generated.
Date: December 2005
Creator: Vicars, Julie Anne Groening

Hyperspectral and Multispectral Image Analysis for Vegetation Study in the Greenbelt Corridor near Denton, Texas

Description: In this research, hyperspectral and multispectral images were utilized for vegetation studies in the greenbelt corridor near Denton. EO-1 Hyperion was the hyperspectral image and Landsat Thematic Mapper (TM) was the multispectral image used for this research. In the first part of the research, both the images were classified for land cover mapping (after necessary atmospheric correction and geometric registration) using supervised classification method with maximum likelihood algorithm and accuracy of the classification was also assessed for comparison. Hyperspectral image was preprocessed for classification through principal component analysis (PCA), segmented principal component analysis and minimum noise fraction (MNF) transform. Three different images were achieved after these pre-processing of the hyperspectral image. Therefore, a total of four images were classified and assessed the accuracy. In the second part, a more precise and improved land cover study was done on hyperspectral image using linear spectral unmixing method. Finally, several vegetation constituents like chlorophyll a, chlorophyll b, caroteoids were distinguished from the hyperspectral image using feature-oriented principal component analysis (FOPCA) method and which component dominates which type of land cover particularly vegetation were correlated.
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Date: August 2006
Creator: Bhattacharjee, Nilanjana

Integrating GIS with Benthic Metrics: Calibrating a Biotic Index to Effectively Discriminate Stream Impacts in Urban Areas of the Blackland Prairie Eco-Region

Description: Rapid Bioassessment Protocols integrate a suite of community, population, and functional metrics, determined from the collection of benthic macroinvertebrates or fish, into a single assessment. This study was conducted in Dallas County Texas, an area located in the blackland prairie eco-region that is semi-arid and densely populated. The objectives of this research were to identify reference streams and propose a set of metrics that are best able to discriminate between differences in community structure due to natural variability from those caused by changes in water quality due to watershed impacts. Using geographic information systems, a total of nine watersheds, each representing a different mix of land uses, were chosen for evaluation. A total of 30 metrics commonly used in RBP protocols were calculated. Efficacy of these metrics to distinguish change was determined using several statistical techniques. Ten metrics were used to classify study area watersheds according to stream quality. Many trends, such as taxa presence along habitat quality gradients, were observed. These gradients coincided with expected responses of stream communities to landscape and habitat variables.
Date: December 2003
Creator: Earnest, Steven F. P.

Interpreting Prehistoric Patterns: Site Catchment Analysis in the Upper Trinity River Basin of North Central Texas

Description: Archaeologically site catchment analysis produces valuable information regarding prehistoric subsistence strategies and social organization. Incorporating archaeological data into catchment analyses is an effective strategy to develop regional models of prehistoric site selection and settlement patterns. Digital access to data permits the incorporation of multiple layers of information into the process of synthesizing regional archaeology and interpreting corresponding spatial patterning. GIS software provides a means to integrate digital environmental and archaeological data into an effective tool. Resultant environmental archaeology maps facilitate interpretive analysis. To fulfill the objectives of this thesis, GIS software is employed to construct site catchment areas for archaeological sites and to implement multivariate statistical analyses of physical and biological attributes of catchments in correlation with assemblage data from sites. Guided by ecological, anthropological and geographical theories hypotheses testing evaluates patterns of prehistoric socio-economic behavior. Analytical results are summarized in a model of prehistoric settlement patterns in North Central Texas.
Date: December 2004
Creator: Williams, Marikka Lin

Measuring the value of transit access for Dallas County: A hedonic approach.

Description: Advocates of urban light rail transit argue that positive developments around station area(s) should offset the costs of implementing a transit system by creating more livable communities and enhance surrounding residential property values. In some cases, decreased urban landscape aesthetics have been reported. The purpose of this study is to contribute to this debate via an analysis of the impact of the Dallas Area Rapid Transit system on residential property values in Dallas County. By examining the impact of distance on property values of two features of the DART system: the transit station and the rail line, and by holding a series of structural variables constant, a net change in value can be calculated using a multi-regression model.
Date: August 2007
Creator: Leonard, Christopher

More buildings about songs and food: A case study of Omaha's Slowdown project.

Description: The success of independent rock music ("indie rock"), once a marginalized sub-genre of the rock idiom and now a globally recognized cultural force, has impacted the urban landscape of Omaha, Nebraska via the mixed-use urban redevelopment project, "Slowdown" - a result of cultural production by the city's successful indie rock business entities. While geographic research has previously analyzed urban redevelopment initiated by fine artists, the event of indie rock music being a catalyst for urban redevelopment has never been considered in a geographic scope. By examining the topics of affordable technological tools, Omaha's reduced cost-of-living, and cooperative efforts by city leaders, insight into how an indie rock "scene" can become a successful urban redevelopment catalyst is gained.
Date: August 2007
Creator: Seman, Michael

National Patterns and Community Impacts of Major Domestic U.S. Military Base Closures, 1988-present

Description: This thesis analyses major U.S. military bases closed by the Base Realignment and Closure (BRAC) Commission since 1988. The study focuses on geographic patterns of pre-existing versus BRAC bases, statistical attributes, environmental restoration, and reuse of bases. Comparative case studies supplement the analysis, highlighting rural versus urban location, success versus failure, politics, conflict, and local versus national goals. Thesis findings are that: 92 bases closed versus 97 commonly published; a fairly even national closure pattern occurred, indicating Commission efforts to achieve equity, except for three closure clusters indicating efforts to consolidate functions in some regions and leave others; base reuse, while commonly perceived negatively, has been positive in most cases; the BRAC process is becoming more efficient, such that allowed years between BRAC closure decisions and base closures should be reduced from six to three years to benefit both communities and the Defense Department.
Date: August 2004
Creator: Webster, Sean T.

The proposed Fastrill Reservoir in east Texas: A study using geographic information systems.

Description: Geographic information systems and remote sensing software were used to analyze data to determine the area and volume of the proposed Fastrill Reservoir, and to examine seven alternatives. The controversial reservoir site is in the same location as a nascent wildlife refuge. Six general land cover types impacted by the reservoir were also quantified using Landsat imagery. The study found that water consumption in Dallas is high, but if consumption rates are reduced to that of similar Texas cities, the reservoir is likely unnecessary. The reservoir and its alternatives were modeled in a GIS by selecting sites and intersecting horizontal water surfaces with terrain data to create a series of reservoir footprints and volumetric measurements. These were then compared with a classified satellite imagery to quantify land cover types. The reservoir impacted the most ecologically sensitive land cover type the most. Only one alternative site appeared slightly less environmentally damaging.
Date: December 2009
Creator: Wilson, Michael Ray