You limited your search to:

  Partner: UNT Libraries
 Degree Discipline: Applied Geography
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
Measuring the value of transit access for Dallas County: A hedonic approach.

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

Date: August 2007
Creator: Leonard, Christopher
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.
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
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.
Contributing Partner: UNT Libraries
Hyperspectral and Multispectral Image Analysis for Vegetation Study in the Greenbelt Corridor near Denton, Texas

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

Access: Use of this item is restricted to the UNT Community.
Date: August 2006
Creator: Bhattacharjee, Nilanjana
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.
Contributing Partner: UNT Libraries
FACET Simulation in the Imataca Forest Reserve, Venezuela: Permanent Plot Data and Spatial Analysis

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

Date: May 2006
Creator: Figuera, Dilcia
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.
Contributing Partner: UNT Libraries
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
GIS Modeling of Wetlands Elevation Change in Response to Projected Sea Level Rise, Trinity Bay, Texas

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

Date: December 2005
Creator: Lee, Erica Anne
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.
Contributing Partner: UNT Libraries
Hydrological Impacts of Urbanization: White Rock Creek, Dallas Texas

Hydrological Impacts of Urbanization: White Rock Creek, Dallas Texas

Date: December 2005
Creator: Vicars, Julie Anne Groening
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.
Contributing Partner: UNT Libraries