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  Partner: UNT Libraries
 Department: Department of Geography
 Decade: 2000-2009
 Degree Level: Master's
 Collection: UNT Theses and Dissertations
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.

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.

Access: Use of this item is restricted to the UNT Community.
Date: December 2005
Creator: Osei-Adjei, Peter
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.
Contributing Partner: UNT Libraries
Assessment of sediment runoff from natural gas well development sites.

Assessment of sediment runoff from natural gas well development sites.

Date: May 2007
Creator: Havens, David Loran
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.
Contributing Partner: UNT Libraries
A Comparative Analysis of Diseases Associated with Mining and Non-Mining Communities: A Case Study of Obusai and Asankrangwa, Ghana

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

Date: August 2005
Creator: Reddy, Sumanth G.
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.
Contributing Partner: UNT Libraries
Comparison of IKONOS Derived Vegetation Index and LiDAR Derived Canopy Height Model for Grassland Management.

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

Date: December 2009
Creator: Parker, Gary
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 ...
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Determining the suitability of functional landscapes and wildlife corridors utilizing conservation GIS methods in Denton County, Texas.

Determining the suitability of functional landscapes and wildlife corridors utilizing conservation GIS methods in Denton County, Texas.

Date: August 2007
Creator: Sales, Joshua
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.
Contributing Partner: UNT Libraries
Developing a wildlife tracking extension for ArcGIS

Developing a wildlife tracking extension for ArcGIS

Date: May 2009
Creator: Chen, Cai
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.
Contributing Partner: UNT Libraries
Differential use of space: An analysis of the Aubrey Clovis site.

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

Date: August 2005
Creator: Witt, Benjamin A.
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.
Contributing Partner: UNT Libraries
Distribution and Probable Sources of Nitrate in the Seymour Aquifer, North Central Texas, USA

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

Access: Use of this item is restricted to the UNT Community.
Date: May 2001
Creator: Hillin, Clifford K.
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.
Contributing Partner: UNT Libraries
An environmental justice assessment of the light rail expansion in Denton County, Texas.

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

Date: August 2007
Creator: Moynihan, Colleen T.
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.
Contributing Partner: UNT Libraries
Estimating Buruli Ulcer Prevalence in Southwestern Ghana

Estimating Buruli Ulcer Prevalence in Southwestern Ghana

Date: August 2007
Creator: Denton, Curtis James
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.
Contributing Partner: UNT Libraries
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