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County Level Population Estimation Using Knowledge-Based Image Classification and Regression Models

Description: 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.
Date: August 2010
Creator: Nepali, Anjeev

The Descriptive Paleontology and Applied Ichthyoarchaeology of the Ponsipa Fauna

Description: The archaeology of the Northern Rio Grande region of New Mexico has recently received an increased amount scholarly attention. In particular, understanding past trends in demographics, agricultural productivity, violence, and social networks have been primary goals of archaeological research. Understanding patterns in animal exploitation has, however, received far less attention due to a small yet growing regional zooarchaeological database. Through the identification of animal remains from a site called Ponsipa (occupied ca. A.D. 1300 to 1600), this thesis adds one large dataset to this growing database. In addition, this thesis expands on the pre-impoundment distribution of an endangered native freshwater fish species in the state of New Mexico called the blue sucker (Cycleptus elongatus). The blue sucker is a unique fish that is currently experiencing range reduction across all of its known North American distribution due to anthropogenic habitat fragmentation and degradation. Skeletal remains that were identified from Ponsipa represent the farthest known northern record of its occurrence in the state of New Mexico and highlight the extent of range restriction of the species in the area. The data concerning the historical biogeography of the blue sucker from Ponsipa have implications for the effective conservation and restoration of blue sucker located in the Rio Grande Basin.
Date: May 2015
Creator: Dombrosky, Jonathan

Dismantling the Psychiatric Ghetto: Evaluating a Blended-Clinic Approach to Supportive Housing in Houston, Texas

Description: Locational decisions based on stigma and low funding have handicapped the efficiency of community based mental healthcare in the United States since 1963. However, the pattern of services in the 21st century American South remains largely unknown. This thesis addresses this gap in knowledge by using a mixed methodology including location allocation, descriptive statistics, and qualitative site visits to explore the geography of community clinics offering both physical and mental health services. The City of Houston has proposed using these facilities to anchor new supportive housing, but introducing more fixed costs to a mismatched system could create more problems than solutions. The findings of this study suggest the presence of an unnecessary concentration of services in the central city and a spatial mismatch between accessible clinics and the poor, sick people in need. Furthermore, this research reveals a new suburban pattern of vulnerability, calling into question long-held assumptions about the vulnerability of the inner city. Building supportive housing around existing community clinics, especially in the central city, may further concentrate vulnerable people thereby contributing to intensifying patterns of service-seeking drift and the continued traumatization of mentally ill homeless persons in Houston.
Date: December 2014
Creator: Lester, Katherine Ann

Efficiency of Nitrate and Phosphorus Removal in a Working Rain Garden

Description: Rain gardens are low impact developments designed to mitigate a suite of issues associated with urban stormwater runoff. The site for this study was a Denton City rain garden at the Denton Waste Water Treatment Plant. Nitrogen and phosphorus removal was examined in light of two overflow events comprised of partially treated wastewater from an upslope anaerobic digester pond. Nitrate removal efficiency was examined across differing dry spell intervals of 5, 8, and 12 d, displaying a moderate negative correlation (r2 = 0.59). Continued phosphorus removal capacity was assessed, showing phosphorus removal in cases where P was in excess of 0.8 mg/L, reflecting an equilibrium phosphorus concentration. A high expanded shale component in the soil media (25%) was likely a factor in the continued removal of phosphorus. Overall the rain garden proved to be a large source of nitrate (+425%) and total nitrogen (+61%) by mass. The study showed that while the rain garden intercepted a large volume of partially treated wastewater during the overflow events, preventing it from reaching a nearby creek, the mitigation of an acute event has extended to a chronic one as nitrogen is gradually processed and flushed from the system as nitrate.
Date: August 2015
Creator: Strong, Patrick

Exceedance Frequency Analysis of Urban Stormwater Quality and Its Relation to Land Use Change, Denton, Texas

Description: Urbanization causes various environmental issues including water pollution, air pollution, and solid waste. Urbanization of watersheds has a profound influence on the quality of stormwater runoff. The quality of stormwater runoff is highly associated with land use. This study analyzed the exceedance frequency of stormwater quality in five watersheds of Denton over eleven years and also analyzed the relationship between stormwater quality and land use/cover of each watershed. The results showed that the most of the water quality parameters that were examined in the Lower Pecan watershed exceeded their threshold most frequently. The higher frequency of exceedance in this watershed can be attributed to the wastewater treatment plant and landfill site. Total suspended solids and turbidity were frequently exceeded in Hickory and Clear Creek watersheds. Conductivity was found to have highest percentage of exceedance in Upper Pecan and Cooper watersheds. Thus, rural watersheds were related with higher exceedance of TSS and turbidity whereas urban watersheds were related with higher exceedance of conductivity.
Date: August 2015
Creator: Shrestha, Manjul

Identifying Cultural and Non-cultural Factors Affecting Litter Patterns in Hickory Creek, Texas

Description: Plastic deposition in hydrological systems is a pervasive problem at all geographic scales from loci of pollution to global ocean circulation. Much attention has been devoted to plastic deposition in marine contexts, but little is known about inputs of plastics into local hydrological systems, such as streams. Any attempt to prevent plastic litter must confront people’s behaviors, so archaeological concepts are used to distinguish between various cultural inputs (e.g., littering) and non-cultural forces (e.g., stream transport) that affect litter patterns on the landscape. Litter surveys along Hickory Creek in Denton, TX, are used to assess these factors.
Date: August 2014
Creator: Carpenter, Evan S.

The Influence of Local Forage Variability on White-tailed Deer (Odocoileus virginianus) Body Size at Fort Hood, Texas

Description: Nutritional quality and availability is thought to regulate geographic patterns of variability in animal body size due to phenotypic plasticity. The purpose of this study is to determine how vegetation quality, abundance and population density influence white-tailed deer (Odocoileus virginianus) body size on a subregional spatial scale at Fort Hood, Texas. Harvest and census records are used to test the hypothesis that white-tailed deer exhibit phenotypic plasticity (e.g. larger body size) in response to differences in vegetation quality and availability. Results from these analyses suggest that forage quality and abundance alone is not a main driver of white-tailed deer body size. Analysis of deer population density (generally) resulted in an inverse relationship with body size. Areas with high quality forage and low population density support larger deer while areas with low quality forage and high density support smaller than average deer. The few exceptions occur in areas exhibiting poor quality forage and low population density or high forage quality and high density. Results from this study suggest that continued overcrowding of deer within isolated areas may eventually lead to efficiency phenotypic conditions producing smaller sized deer. These results could prove useful in interpreting deer population responses to harvest management. For successful local management of deer, studies examining the combined influence of habitat variables (such as forage quality, abundance and population density) on deer health offer managers valuable information needed to establish annual harvest goals and understand deer-habitat relationships relative to carrying capacity.
Date: December 2015
Creator: Eddins, Amy C.

Influence of the Choice of Disease Mapping Method on Population Characteristics in Areas of High Disease Burdens

Description: Disease maps are powerful tools for depicting spatial variations in disease risk and its underlying drivers. However, producing effective disease maps requires careful consideration of the statistical and spatial properties of the disease data. In fact, the choice of mapping method influences the resulting spatial pattern of the disease, as well as the understanding of its underlying population characteristics. New developments in mapping methods and software in addition to continuing improvements in data quality and quantity are requiring map-makers to make a multitude of decisions before a map of disease burdens can be created. The impact of such decisions on a map, including the choice of appropriate mapping method, not been addressed adequately in the literature. This research demonstrates how choice of mapping method and associated parameters influence the spatial pattern of disease. We use four different disease-mapping methods – unsmoothed choropleth maps, smoothed choropleth maps produced using the headbanging method, smoothed kernel density maps, and smoothed choropleth maps produced using spatial empirical Bayes methods and 5-years of zip code level HIV incidence (2007- 2011) data from Dallas and Tarrant Counties, Texas. For each map, the leading population characteristics and their relative importance with regards to HIV incidence is identified using a regression analysis of a CDC recommended list of socioeconomic determinants of HIV. Our results show that the choice of mapping method leads to different conclusions regarding the associations between HIV disease burden and the underlying demographic and socioeconomic characteristics. Thus, the choice of mapping method influences the patterns of disease we see or fail to see. Accurate depiction of areas of high disease burden is important for developing and targeting appropriate public health interventions.
Date: December 2015
Creator: Desai, Khyati Sanket

Retail Change and Light Rail: an Exploration of Business Location Changes Accompanying Commuter Rail Development in Denton County, Texas

Description: Within the past few decades, commuter rail routes in several major metropolitan areas have been implemented to provide an alternative to automobile transportation. Urban planners in these cities are looking to commuter rail to mitigate congestion and pollution. However, research on the impacts of commuter rail development on the surrounding retail landscape is still needed. In metropolitan Dallas-Fort Worth, the Denton County Transportation Authority recently opened its new A-Train light rail service linking suburban Denton and downtown Dallas. This thesis examines urban changes that occurred in the years before and after the A-Train line's 2011 opening, with a focus on restaurant and retail development in the vicinity of the A-Train stations in Denton County. This analysis evaluates changes in retail density and type, the population surrounding stations, and municipal initiatives that shape the retail landscape of station vicinities. This was done by gathering field data, retailer listings, population data, and conducting interviews with local businesses and city planners. The findings suggest that A-train stations have had a differential impact on the surrounding landscape, depending on the existing retail landscape, the types of retailers present, and the current state of municipal infrastructure that promotes accessibility. Overall, results suggest that urban planners play a vital role in harnessing the potential of commuter rail to promote nearby retail growth.
Date: August 2014
Creator: Yarbrough, Trevor S.

Small Town Retail Change in East Texas: an Analysis of Retail Growth, Decline, and Spatial Reconfiguration

Description: In recent years, small towns have experienced declining levels of retail activity attributable to a variety of factors. Previously conducted research identifies a number of these factors such as changing population dynamics, continuously evolving retail practices, locational factors, and an assortment of other macroeconomic factors. Although retail decline is common for many small towns, there are some small towns that have been able to maintain their viability in an ever-changing economic climate. The primary purpose of this research is to better understand what spatial and socio-economic characteristics contribute to retail growth and decline in a series of small towns. This research highlights a selection of small towns across a 14 county area within east Texas. The selection of small towns includes a number of towns with an increasing number of retail establishments as well as a number of towns with decreasing retail establishments over the 14 year study timeframe. Contained within this research is a discussion of small town economic and retail development, as well as findings regarding spatial and socio-economic characteristics as they relate to retail growth and decline in small towns. This research finds that locational characteristics do have an effect on retail growth and decline. The research also supports the literature, which states retail growth and decline is more pronounced within certain retail categories.
Date: December 2015
Creator: Whitaker, Carl W.

Structure, Composition, and Regeneration of Cross Timbers Forest Fragments in Different Land Use Contexts

Description: Throughout its current range, the Cross Timbers forest ecosystem is vulnerable to land-use change. In this study, we examined the surrounding land use matrix on the vegetation structure, composition and regeneration of six Cross Timbers forest fragments in Denton County, Texas (north of the Dallas-Fort Worth metroplex). Two fragments adjacent to agricultural land, two to residential neighborhoods, and two formally protected forest sites were selected. In summer 2015, five 100 m2 plots were randomly established in each fragment at least 200 meters from the edge. In each plot, all live and dead trees ≥ 3 cm diameter were identified and their height and diameter at breast height (DBH at 1.3 m aboveground) measured. Evidence of dumping (presence of trash) was recorded as an index of human frequentation. Differences in vegetation structure among the forest fragments were found. Most notably, fragments adjacent to agriculture contained 25% to 50% fewer trees per hectare than all other sites (Kruskal-Wallis, p < 0.02), especially trees <10 cm DBH. However, residential fragments had fewer trees that were ≥15 cm DBH compared to the other fragments, indicating that these are the youngest of the forest patches surveyed. Trash was observed in 60% of plots surveyed at residential forest sites, showing high levels of human frequentation compared to the protected and agricultural forest sites. Agricultural sites contained the lowest number of recorded tree species and were most similar to each other, sharing 91% of species. These findings indicate that surrounding land use affects forest structure and composition, consequently affecting valuable ecosystem services including wildlife habitat, aesthetics and recreation.
Date: May 2015
Creator: Dunn, Ingrid

The Use of Faunal Remains for Identifying Shifts in Pit Structure Function in the Mesa Verde Region: a Case Study From Goodman Point

Description: The archaeofaunal remains left by the Ancestral Puebloan people of Goodman Point Unit provides a valuable, yet underutilized resource into pit structure function. This thesis explores temporal changes in pit structure use and evaluates if a final feast occurred during a kiva decommissioning. The results from zooarchaeological analyses of a pithouse and two great kivas suggest that changes in pit structures at Goodman Point mimic the regional trend toward specialization until late Pueblo III. Cross-cultural studies on feasts, southwest ethnographies and previous zooarchaeological work established methods for identifying a feast. The analysis of differences in faunal remains from a great kiva and multiple room block middens imply that the remains in the kiva were from a final feast prior to a decommissioning ceremony and were not fill. Spatially and temporally the great kiva appears to be a unique, specialized structure in the cultural development of the Goodman Point community.
Date: August 2015
Creator: Winstead, Christy

Zooarchaeology and Biogeography of Freshwater Mussels in the Leon River During the Late Holocene

Description: The Leon River, a small-medium river in central Texas, is highly impacted by multiple impoundments, enrichment from agricultural runoff, and decreased dissolved oxygen levels. This degraded river contains sixteen unionid species, two of which are both endemic to the region and candidates for the federal endangered species listing (Quadrula houstonensis and Truncilla macrodon). While there is a short historical record for this river basin and a recent modern survey completed in 2011, zooarchaeological data adds evidence for conservation efforts by increasing the time depth of data available and providing another conservation baseline. Zooarchaeological data for the Leon River is available from the two Late Holocene archaeological sites: 41HM61 and the Belton Lake Assemblages. Data generated from these assemblages describe the prehistoric freshwater mussel community of the Leon River in terms of taxonomic composition and structure. By comparing this zooarchaeological data to the data generated by the longitudinal modern survey of the Leon River, long term changes within the freshwater mussel community can be detected. A conceptual model is constructed to evaluate how robusticity, identifiability, and life history ecology affect unionid taxonomic abundances in zooarchaeological data. This conceptual model functions as an interpretive tool for zooarchaeologists to evaluate forms of equifinality in zooarchaeological assemblages. This thesis determines differences between the late Holocene and modern freshwater community of the Leon River, explores how different alternative mechanisms influence zooarchaeological data, and exemplifies of how zooarchaeological data can be used for conservation biology.
Date: May 2015
Creator: Popejoy, Traci Glyn