170 Matching Results

Search Results

Advanced search parameters have been applied.

Issues and Challenges for Federal Geospatial Information

Description: The report discusses issues that may be of interest to Congress-managing, sharing, and coordinating geospatial information-and includes examples of legislation. The report also summarizes a diverse set of recommendations and proposals from different non-governmental organizations for how to improve the coordination and management of geospatial information at the federal and state levels.
Date: April 27, 2012
Creator: Folger, Peter
Partner: UNT Libraries Government Documents Department

Issues and Challenges for Federal Geospatial Information

Description: The report discusses issues that may be of interest to Congress-managing, sharing, and coordinating geospatial information-and includes examples of legislation. The report also summarizes a diverse set of recommendations and proposals from different non-governmental organizations for how to improve the coordination and management of geospatial information at the federal and state levels.
Date: May 18, 2011
Creator: Folger, Peter
Partner: UNT Libraries Government Documents Department

A comparison of universal soil loss equation results using a remote sensing/GIS technique to results obtained using a field survey technique

Description: Digital satellite remote sensing and Geographic Information Systems (GIS) have been used in conjunction with the Universal Soil Loss Equation (USLE) to model soil erosion potential within watersheds. This study compared erosion estimates calculated by the remote sensing method to results obtained in the field by soil conservationists using conventional methods.
Date: December 1990
Creator: Hunter, Bruce Allan
Partner: UNT Libraries

Use of geographic information systems for assessing ground water pollution potential by pesticides in central Thailand

Description: This study employed geographic information systems (GIS) technology to evaluate the vulnerability of groundwater to pesticide pollution. The study area included three provinces (namely, Kanchana Buri, Ratcha Buri, and Suphan Buri) located in the western part of central Thailand. Factors used for this purpose were soil texture, percent slope, primary land use, well depth, and monthly variance of rainfall. These factors were reclassified to a common scale showing potential to cause groundwater contamination by pesticides. This scale ranged from 5 to 1 which means high to low pollution potential. Also, each factor was assigned a weight indicating its influence on the movement of pesticides to groundwater. Well depth, the most important factor in this study, had the highest weight of 0.60 while each of the remaining factors had an equal weight of 0.10. These factors were superimposed by a method called “arithmetic overlay” to yield a composite vulnerability map of the study area. Maps showing relative vulnerability of groundwater to contamination by pesticides were produced. Each of them represented the degree of susceptibility of groundwater to be polluted by the following pesticides: 2,4-D, atrazine, carbofuran, dicofol, endosulfan, dieldrin & aldrin, endrin, heptachlor & heptachlor epoxide, total BHC, and total DDT. These maps were compared to groundwater quality data derived from actual observations. However, only the vulnerability maps of atrazine, endosulfan, total BHC, and heptachlor & heptachlor epoxide showed the best approximation to actual data. It was found that about 7 to 8%, 83 to 88% and 4.9 to 8.7% of the study area were highly, moderately, and lowly susceptible to pesticide pollution in groundwater, respectively. In this study a vulnerability model was developed, which is expressed as follow: V = 0.60CW + 0.10CS + 0.10CR + 0.10CL + 0.10CSL. Its function is to calculate a vulnerability score for a certain ...
Date: August 2002
Creator: Thapinta, Anat
Partner: UNT Libraries

Using Geographic Information Systems for the Functional Assessment of Texas Coastal Prairie Freshwater Wetlands Around Galveston Bay

Description: 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.
Date: May 2010
Creator: Enwright, Nicholas
Partner: UNT Libraries

A comparison of least squares regression and geographically weighted regression modeling of West Nile virus risk based on environmental parameters

Description: This article discusses the effectiveness of utilizing local spatial variations in environmental data to uncover the statistical relationships between West Nile Virus (WNV) risk and environmental factors.
Date: March 28, 2017
Creator: Kala, Abhishek K.; Tiwari, Chetan; Mikler, Armin R. & Atkinson, Samuel F.
Partner: UNT College of Arts and Sciences

Emergency Fire Response in Ghana: The Case of Fire Stations in Kumasi

Description: Comprehensive emergency management and response is crucial for disaster prevention and health emergencies. However, in African countries with an abundance of natural disasters and a rising surge in cardiovascular and obstetric emergencies, little research exists on emergency response. This study examines the fire emergency response in Kumasi Metropolitan Assembly (KMA), Ghana's second largest city. We use Geographic Information Systems (GIS) tools including location -allocation modeling to evaluate the existing system of fire facilities, identify gaps in service, and suggest locations for new fire stations to maximize population coverage. Our results show that fire stations within KMA are poorly distributed and large portions of the metropolis are underserved, a situation that is partly responsible for the huge losses of lives and property during fire outbreaks.
Date: May 2017
Creator: Boakye, Kwadwo Adu
Partner: UNT Libraries

A geospatial tool for assessing potential wildland fire risk in central Texas.

Description: Wildland fires in the United States are not always confined to wilderness areas. The growth of population centers and housing developments in wilderness areas has blurred the boundaries between rural and urban. This merger of human development and natural landscape is known in the wildland fire community as the wildland urban interface or WUI, and it is within this interface that many wildland fires increasingly occur. As wildland fire intrusions in the WUI increase so too does the need for tools to assess potential impact to valuable assets contained within the interface. This study presents a methodology that combines real-time weather data, a wildland fire behavior model, satellite remote sensing and geospatial data in a geographic information system to assess potential risk to human developments and natural resources within the Austin metropolitan area and surrounding ten counties of central, Texas. The methodology uses readily available digital databases and satellite images within Texas, in combination with an industry standard fire behavior model to assist emergency and natural resource managers assess potential impacts from wildland fire. Results of the study will promote prevention of WUI fire disasters, facilitate watershed and habitat protection, and help direct efforts in post wildland fire mitigation and restoration.
Date: August 2005
Creator: Hunter, Bruce Allan
Partner: UNT Libraries

Geospatial Information and Geographic Information Systems (GIS): Current Issues and Future Challenges

Description: This report provides a primer on geospatial data and GIS and provides several examples of their use. The report discusses issues that may be of interest to Congress: sharing, coordination, and management of geospatial information, including examples of legislation. Finally, recommendations are included from several organizations for how to improve the coordination and management of geospatial information at the federal and state levels.
Date: June 8, 2009
Creator: Folger, Peter
Partner: UNT Libraries Government Documents Department

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.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: May 2001
Creator: Donkor, Kweku
Partner: UNT Libraries

Geospatial Information and Geographic Information Systems (GIS): An Overview for Congress

Description: The report discusses issues that may be of interest to Congress-managing, sharing, and coordinating geospatial information-and includes examples of legislation. The report also summarizes a diverse set of recommendations and proposals from different non-governmental organizations for how to improve the coordination and management of geospatial information at the federal and state levels.
Date: May 18, 2011
Creator: Folger, Peter
Partner: UNT Libraries Government Documents Department

Modelling land use change and nonpoint source pollution potential using remote sensing and geographic information system technology

Description: In this study Geographic Information System (GIS) technology was integrated with remote sensing techniques in order to determine the potential for nonpoint source pollution in the Lake Palestine and Cedar Creek Reservoir watersheds of North Central Texas. The Universal Soil Loss Equation was used to determine soil erosion potential from the watersheds, and export coefficients were used to estimate nutrient loadings into the reservoirs.
Date: August 1990
Creator: Walker, Scott William
Partner: UNT Libraries

An analysis of adding land cover as a variable to the DRASTIC ground water model

Description: This study involved a geographic information systems (GIS) approach to modeling ground water pollution potential in the Southern Edwards Aquifer Region in Texas. The DRASTIC ground water model was analyzed using two methods. First, the effects of adding land cover data to the drastic model were evaluated. In the second approach, the effects of the removal of DRASTIC variables were evaluated. Six, five, and four variable models were generated and analyzed.
Date: December 1993
Creator: Klingler, Thomas H. (Thomas Henry)
Partner: UNT Libraries

GIS in AP Human Geography: a Means of Developing Students’ Spatial Thinking?

Description: Geography education is undergoing change in K-12 education due in part to the introduction of geospatial technologies, including geographic information systems (GIS). Although active engagement in GIS mapping would seem to enhance students’ spatial thinking, little is known about the mapping strategies that students employ or about changes in their geographic knowledge that would result. This study, set in a high school Advanced Placement human geography class, sought to contribute to these areas of inquiry. Participants performed a web-based GIS task focused on global population and migration. Attention in the study was on (a) the strategies students employed when investigating geographic phenomena using GIS, (b) changes in their cognitive maps, as assessed through sketch maps, resulting from the activity, (c) the relationship between GIS maps and sketch maps, and (d) the ways in which a subset of students serving as case studies explained the nature of their mapping. The study employed screen-captures, video-recordings, observations, pre- and post-study sketch maps, and interviews. Analyses of the GIS process revealed that, in creating their maps, the students used a number of strategies, which included searching, layering, removing layers of data, adjusting transparency, editing, and noting. Although searching and layering were employed by all students, there was variability across students in use of the other strategies. With respect to changes in their spatial thinking, analyses of the sketch maps showed increases in elaboration and accuracy in terms of migration patterns. When GIS maps were compared to sketch maps, analyses showed relations for many students. The six students who served as case studies revealed major connections between personal interests and the reasoning employed in mapping. They also described their entry points into the process. The study shows how real-time data collection, including screen captures, as well as more static measures, specifically sketch maps, can provide ...
Date: May 2015
Creator: Webster, Megan L.
Partner: UNT Libraries

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
Partner: UNT Libraries

Determining the Effectiveness of Incorporating Geographic Information Into Vehicle Performance Algorithms

Description: This thesis presents a research study using one year of driving data obtained from plug-in hybrid electric vehicles (PHEV) located in Sacramento and San Francisco, California to determine the effectiveness of incorporating geographic information into vehicle performance algorithms. Sacramento and San Francisco were chosen because of the availability of high resolution (1/9 arc second) digital elevation data. First, I present a method for obtaining instantaneous road slope, given a latitude and longitude, and introduce its use into common driving intensity algorithms. I show that for trips characterized by >40m of net elevation change (from key on to key off), the use of instantaneous road slope significantly changes the results of driving intensity calculations. For trips exhibiting elevation loss, algorithms ignoring road slope overestimated driving intensity by as much as 211 Wh/mile, while for trips exhibiting elevation gain these algorithms underestimated driving intensity by as much as 333 Wh/mile. Second, I describe and test an algorithm that incorporates vehicle route type into computations of city and highway fuel economy. Route type was determined by intersecting trip GPS points with ESRI StreetMap road types and assigning each trip as either city or highway route type according to whichever road type comprised the largest distance traveled. The fuel economy results produced by the geographic classification were compared to the fuel economy results produced by algorithms that assign route type based on average speed or driving style. Most results were within 1 mile per gallon ({approx}3%) of one another; the largest difference was 1.4 miles per gallon for charge depleting highway trips. The methods for acquiring and using geographic data introduced in this thesis will enable other vehicle technology researchers to incorporate geographic data into their research problems.
Date: April 1, 2012
Creator: White, Sera
Partner: UNT Libraries Government Documents Department

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
Partner: UNT Libraries

USE OF THE AERIAL MEASUREMENT SYSTEM HELICOPTER EMERGENCY RESPONSE ACQUISITION SYSTEMS WITH GEOGRAPHIC INFORMATION SYSTEM FOR RADIOACTIVE SOIL REMEDIATION - [11504]

Description: The Aerial Measurement System (AMS) Helicopter Emergency Response Acquisition System provides a thorough and economical means to identify and characterize the contaminants for large area radiological surveys. The helicopter system can provide a 100-percent survey of an area that qualifies as a scoping survey under the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) methodology. If the sensitivity is adequate when compared to the clean up values, it may also be used for the characterization survey. The data from the helicopter survey can be displayed and manipulated to provide invaluable data during remediation activities.
Date: February 15, 2011
Creator: CT, BROCK
Partner: UNT Libraries Government Documents Department

FEMA Flood Map Modernization Funding

Description: This report discusses the implementation of the Federal Emergency Management Agency (FEMA)'s Flood Map Modernization (Map Mod) Initiative (FMMI) and its ongoing Map Mod program. FEMA introduced the FMMI in September 1997 as a strategic plan to convert paper flood insurance rate maps (FIRMs) to digital electronic format, or DFIRMs.
Date: May 1, 2008
Creator: Morrissey, Wayne A.
Partner: UNT Libraries Government Documents Department

GIS Operations at the U.S. Department of Energy’s Hanford Site: A Review of the Current Status and a Proposed Action to Ensure Long-Term Data Sustainability

Description: This paper provides a current state of spatial data collections, use, management, and challenges at the Hanford Site through the use and development of a Spatial Data Infrastructure. Recommendations designed to ensure data quality, usability and sustainability now and into the future are presented.
Date: July 27, 2005
Creator: Coleman, Andre M. & Webber, William D.
Partner: UNT Libraries Government Documents Department