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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A Framework for Evaluating and Assessing the Effects of Urban Growth on Protected Areas

Yeasmin, Dilruba January 2011 (has links)
Protecting and managing National Parks and Monuments effectively is very important for their future sustainability. Urban encroachment on areas adjacent to protected areas is often considered a potential threat to the natural resources inside the protected areas. To minimize these threats, evaluating and assessing the effects of urban encroachment on protected areas and developing effective management strategies is critical. To implement any management strategy, interactions, support and perceptions of changing conditions from neighboring communities is imperative. The goal of this study was to develop a framework to assess perception of land use change along the borders surrounding Saguaro National Park East. The objectives of this study were to determine 1) the change in landscape that has occurred as a result of urban encroachment in and adjacent areas to Saguaro National Park (SNP) over a 15 year period 2) the degree to which neighbors surrounding SNP perceive that these changes have occurred due to urban encroachment 3) the perception of neighbors surrounding SNP that increased urbanization has led to more impacts on local wildlife 4) the possible planning and management strategies that neighbors agree would lead to reduce impacts of urban encroachment on protected areas and how strongly do they support the implementation of these proposed planning and management strategies. Results of this study indicated that landuse / landcover changes have occurred over the landscape at a rapid rate and in large areas within one mile of lands adjacent to the boundary of SNP East. Urban area increased 2.45%, agricultural lands decreased 76.15% and forested lands decreased 6.19% from its previous class in one mile adjacent land to the park from 1992 - 2001. Building units (residential) increased dramatically by 71.53% in this one mile buffer in the period between 1992 and 2007. In addition, respondents that live in adjacent lands perceive these changes over the landscape due to urban encroachment at a moderate degree strongly agree that increased urbanization has led to more negative impacts on local wildlife. Further, respondents strongly support more communication between authorities, developers and neighbors and environmental education programs with regards to urban encroachment on SNP.
2

A Web-based Geographical Information System for Low Bandwidth Access

Shi, Zhennan January 2007 (has links)
The Geographic Information Systems (GIS) have become popular tool, used in different fields. The launching of Google Maps offered a new approach of building web based GIS systems; making it possible to integrate external geographically referenced data with the powerful map service supplied by Google. This thesis demonstrates the design and implementation of creating a web based geographic information system. The system is built by adapting the Google Maps API library and building a web server to display and explore agricultural data.
3

Analysis Of Conservation Practices In The Blackland Prairie Region Of Mississippi And Construction Of A Predictor For Locating New Sites For Conservation Efforts

Hughes, Steven Cameron 30 April 2011 (has links)
Mississippi’s Blackland Prairie has been reduced below 10% of pre-Columbian extent, with few conservation practices in place. To determine efficacy of current restoration practices, plant species at remnant sites were compared with those at restoration sites. Analyses using multivariate statistical approaches revealed no generalizable patterns among four available remnants versus two available restoration sites. Thus, the aim of this project shifted to evaluating methods of identifying Blackland Prairie remnants or potential restoration sites. Location data for Blackland Prairie plant species and potentially informative environmental variables were used to develop geographic information system (GIS)-based habitat models. The best models were selected for validation against a second set of data collected from random points on public lands across the survey region. Validation surveys also were used to explore trends in predictive success and to aid in increasing accuracy through inclusion of other variables. Models incorporating soil characteristics had the highest predictive success.
4

Geographic information system usability and decision support for rural health policy

Bond, Jason 02 May 2016 (has links)
With the rising cost of health care, the debate about where each dollar is spent is putting increasing pressure on decision makers. Consequently, one of the biggest challenges of providing health care to rural populations, specifically, is determining which communities should receive funding to address access to services. Defining rurality in the context of health care is a challenge that governments and health care providers have struggled with for years. Each stakeholder in Canada’s health care system has developed different criteria for defining rurality to inform policy. Currently there is a gap in academic research exploring the benefits of applying Geographic Information Systems (GIS) in rural health care policy and program decision support. GIS can provide insight into rural health care accessibility by modeling and measuring the way patients seek medical treatment. This thesis seeks to explore usability mapping issues and identify how policy makers perceive rurality when presented with information displayed on a map. Usability in this study influenced the perceived usefulness of the mapping tool. Overall study participants felt that mapping tools should be used as a form of decision support in rural health policy issues. Mapping was seen as tool to obtain quicker consensus among decision makers, to provide more context to rural issues in the study scenario, and used as a platform which could potentially assist in the identification of new criteria used to define rural health policy. In terms of usability, system usability design principles play a key role in the success and adoption of mapping tools among rural health policy makers. The study found that Google Earth’s software design violated Nielsen’s usability design principles in the following categories: Help and Documentation, User Control and Freedom, and Navigation. Despite these usability issues, participants found the mapping tool to have three main advantages over the paper-based decision support, the tool allowed them to: 1) gain a more complete picture of the surrounding communities; 2) understand the proximity of health services; and 3) gain greater awareness of the geography of the area. / Graduate
5

Uma análise de acessibilidade sob a ótica da eqüidade - o caso da região metropolitana de Belém. / Assessing equity in transportation accessibility distribution: the case of Belém Metropolitan Region

Goto, Massa 13 September 2000 (has links)
Belém sofreu processo semelhante a diversas cidades brasileiras, com a expulsão de parte da população para áreas de expansão com carência de infra-estrutura viária e, em geral, prejudicadas em termos de acessibilidade. Considerando que este processo atingiu de forma desigual aos diferentes segmentos da população, o objetivo deste trabalho é avaliar como se dá a distribuição de acessibilidade ao transporte para indivíduos de diferentes classes de renda e, a partir daí, analisar estratégias para assegurar a eqüidade na sua distribuição na Região Metropolitana de Belém (RMB). Com este fim, dois índices de acessibilidade foram calculados neste estudo a partir da aplicação de um sistema de informações geográficas para transportes: um do tipo separação espacial média e outro do tipo gravitacional. Os valores de atratividade do índice do tipo gravitacional foram posteriormente alterados de forma a compor dois cenários de localização de pólos de comércio e serviços diferentes do atual. O estudo mostra que os cenários alternativos promoveram uma melhor distribuição da acessibilidade na RMB e que a seleção do melhor deles pode ser feita através de critérios de eqüidade. Além disto, demonstrou-se ainda que, após a seleção do melhor cenário, outros recursos do SIG podem ser utilizados para priorizar, também segundo a ótica da eqüidade, as zonas que ainda carecem de melhorias na acessibilidade aos transportes. / The growth process of Belém, similarly to what happened to other Brazilian cities, was characterized by the location of part of its population in areas with insufficient road infrastructure. As a consequence, these were in general low accessibility areas. Considering that the impacts of the growth process were not evenly distributed to all population groups, the aim of this work is to evaluate the distribution patterns of transportation accessibility to different income groups in the Metropolitan Region of Belém. This is an important step towards the formulation of strategies to reestablish equity in the accessibility distribution. Two indexes have been used to estimate accessibility values in a geographic information system environment: a Mean Separation Index and a Gravity-type Index. The attractiveness values of the Gravity-type Index were subsequently changed to create alternative scenarios in which the location of the retail and service areas was different from the current conditions. The results found in this study showed that: a) the alternative scenarios had a better transportation accessibility distribution than the present one; and b) the selection of the best alternative scenario could be based on equity criteria. Next, once again oriented by an equity criterion, other GIS tools were applied to select the areas in the chosen scenario in which transportation accessibility could be further improved.
6

Uma análise de acessibilidade sob a ótica da eqüidade - o caso da região metropolitana de Belém. / Assessing equity in transportation accessibility distribution: the case of Belém Metropolitan Region

Massa Goto 13 September 2000 (has links)
Belém sofreu processo semelhante a diversas cidades brasileiras, com a expulsão de parte da população para áreas de expansão com carência de infra-estrutura viária e, em geral, prejudicadas em termos de acessibilidade. Considerando que este processo atingiu de forma desigual aos diferentes segmentos da população, o objetivo deste trabalho é avaliar como se dá a distribuição de acessibilidade ao transporte para indivíduos de diferentes classes de renda e, a partir daí, analisar estratégias para assegurar a eqüidade na sua distribuição na Região Metropolitana de Belém (RMB). Com este fim, dois índices de acessibilidade foram calculados neste estudo a partir da aplicação de um sistema de informações geográficas para transportes: um do tipo separação espacial média e outro do tipo gravitacional. Os valores de atratividade do índice do tipo gravitacional foram posteriormente alterados de forma a compor dois cenários de localização de pólos de comércio e serviços diferentes do atual. O estudo mostra que os cenários alternativos promoveram uma melhor distribuição da acessibilidade na RMB e que a seleção do melhor deles pode ser feita através de critérios de eqüidade. Além disto, demonstrou-se ainda que, após a seleção do melhor cenário, outros recursos do SIG podem ser utilizados para priorizar, também segundo a ótica da eqüidade, as zonas que ainda carecem de melhorias na acessibilidade aos transportes. / The growth process of Belém, similarly to what happened to other Brazilian cities, was characterized by the location of part of its population in areas with insufficient road infrastructure. As a consequence, these were in general low accessibility areas. Considering that the impacts of the growth process were not evenly distributed to all population groups, the aim of this work is to evaluate the distribution patterns of transportation accessibility to different income groups in the Metropolitan Region of Belém. This is an important step towards the formulation of strategies to reestablish equity in the accessibility distribution. Two indexes have been used to estimate accessibility values in a geographic information system environment: a Mean Separation Index and a Gravity-type Index. The attractiveness values of the Gravity-type Index were subsequently changed to create alternative scenarios in which the location of the retail and service areas was different from the current conditions. The results found in this study showed that: a) the alternative scenarios had a better transportation accessibility distribution than the present one; and b) the selection of the best alternative scenario could be based on equity criteria. Next, once again oriented by an equity criterion, other GIS tools were applied to select the areas in the chosen scenario in which transportation accessibility could be further improved.
7

Spatiotemporal correlation analysis of colorectal cancer late-stage incidence, mortality, and survival: Iowa, 1999 to 2010

Matthews, Kevin Andrew 01 August 2018 (has links)
This study of the spatiotemporal patterns of colorectal cancer (CRC) in Iowa introduced the importance of examining the geographic patterns of four epidemiological measures (incidence, late-stage incidence, mortality, and survival) as inter-related phases in the natural history of the disease rather than as independent measures. To conduct such an analysis required the development of a framework for conducting spatiotemporal correlation analysis involving two or more measures across two or more periods. This framework is based on geographic units called spatially adaptive filter areas.which effectively address the small number problem. This common spatial epidemiology problem occurs when the population in a unit of geography is too small to calculate a reliable disease rate. The spatially adaptive filter areas are created by aggregating smaller geographic units which, by themselves, do not have sufficiently large populations to calculate statistically reliable disease rates. Conducting spatiotemporal analysis magnifies the small number problem because stratifying disease data by time further reduces the sample sizes in each period, thus increasing the potential for unreliable disease rates. This spatiotemporal framework satisfies two conditions: 1) the rates of each measure in all small areas in the study region meet a minimum level of statistical reliability in all periods, and 2) the disease outcomes measured for one period relies on the same geographic units as the rates calculated for all other periods and measures. We applied the spatiotemporal framework to colorectal cancer data collected in the state of Iowa between 1999 and 2010. Using rates calculated in spatial filter areas, we found that the proportion of cases diagnosed at a late-stage among the population at risk for CRC is more correlated with CRC mortality than when late-stage is measured as the proportion of late-stage cases among the CRC cases diagnosed at any stage. We also found that, when measured in the context of the statewide change, an observed decline in the rate of CRC mortality in a small area does not necessarily mean that its level of mortality is improving. We also found that the correlation between rates of CRC mortality and the survival time among patients diagnosed with CRC varied across Iowa. The results described in this dissertation could potentially reduce the burden of colorectal cancer and improve the health of communities by providing public health professionals and cancer control specialists with evidence to enhance their decision-making processes.
8

Spatially-Weighted Ethnic Density and Residential Segregation: Effects on Health Status among Older Mexican Americans

Rhew, Sung Han 10 April 2015 (has links)
Research suggests that living in communities with high densities of persons from their own ethnic group improves the overall health of older Mexican Americans. One hypothesis is that residing in high ethnic density areas allows characteristics of Mexican culture such as strong social ties and social cohesion, to have a beneficial effect. The majority of investigations focused on ethnic density effects, however, have utilized relatively loose interpretations of what constitutes the appropriate social-geographic area to be studied. Moreover it is not clear how certain dimensions of residential segregation are protective or harmful toward health, particularly when measuring ethnic residential segregation from a geographic information systems (GIS) perspective. The effects of ethnic density and segregation have not been directly or quantitatively tested using the kind of multi-level methodology that can effectively capture data from both personal and environmental characteristics. The present study assessed how multiple geographic/neighborhood factors including ethnic density, neighborhood social cohesion, and social ties may serve as resources for health and health service use of older Mexican Americans. The study had three objectives: 1. To examine whether protective/deleterious effects of ethnic density exist when we use the more commonly used approach to measuring ethnic density (proportion of ethnic group within a specific census unit), and whether the ethnic density effect is increased when an alternative measurement approach (proximity weighted density) is used that relies on more than a single, specific census unit . 2. To examine how different dimensions of ethnic segregation are related to perceived social support, number of social ties, and perception of social cohesion in their neighborhood. 3. To examine whether or not social cohesion mediate the relationship between ethnic density or segregation and health status/health service use. The study represents a secondary analysis of data from the fifth interview wave of the Hispanic Established Populations for the Epidemiologic Study (H-EPESE; PI: Markides). Using geographic information systems (GIS), proximity weighted ethnic density and residential segregation indices were calculated, as well as more standard measures of density based on composition of the census tract in which participant lived. Since the H-EPESE dataset has a clustered structure where individuals are nested within neighborhoods, multilevel modeling techniques were employed. Results suggest that the several approaches here employed to measure ethnic composition of the local environment are complementary. First, the proportion of Hispanics in the neighborhood as defined by the use of census tracts, is both simple and the data easily accessible to researchers. This proportion, or what is often called density, was found to associate with several outcome measures in much the same way, and with similar proportions of variance as the more complex ways of method. The latter, however, made significant contributions that often were relatively independent of the census tract based proportions and thus add significantly to our understanding of the role of the ethnic neighborhood. These more complex measures, moreover, may potentially contribute even more: analyses using these newer approaches were limited by the lack of street address or census block data. Access to such data was not possible due to confidentiality issues surrounding the use of highly specific geographic information that could potentially identify the participant. Results did strongly suggest the value of a residential segregation index as a means of demonstrating that the ethnic environment and urban-rural composition of the residential environment contributes to our understanding of the importance of social coherence and social ties. It was found for example that older Mexican Americans who lived in neighborhoods with higher exposure segregation (i.e., neighborhoods where an individual from one particular racial/ethnic group has a higher probability of encountering members of another group, rather than from their own group) have higher depressive symptoms, as measured by the Center for Epidemiologic Studies Depression (CES-D) scale. This relationship was mediated by individual level data on perception of social cohesion. While in all cases causal interpretations were limited by the lack of a true experimental design the results generally do demonstrate the value of the newer, complementary, approaches to assessment of racial/ethnic density.
9

Geospatial data sharing in Saudi Arabia

Lee, Donald C. January 2003 (has links)
This research started with a realization that two organizations in Saudi Arabia were spending large amounts of money, millions of dollars in fact, in acquiring separate sets of geospatial data that had identical basemap components. Both the organizations would be using the data for similar engineering purposes, yet both would be independently outsourcing the data gathering. In all probability, resources are being wasted through two organizations each developing and operating stand-alone geographic information systems and then populating the databases with geospatial data obtained separately. Surely with some cooperation, a shared database could be established, with a diffusion of economic benefits to both organizations. Preliminary discussions with representatives from both the organizations revealed high levels of enthusiasm for the principle of sharing geospatial data, but the discussions also revealed even higher levels of scepticism that such a scheme could be implemented. This dichotomy of views prompted an investigation into the issues, benefits and the barriers involved in data sharing, the relative weight of these issues, and a quest for a workable model. Sharing geospatial data between levels of government, between governmental and private institutions, and within institutions themselves has been attempted on large and small scales in a variety of countries, with varying degrees of accomplishment. Lessons can be learned from these attempts at data sharing, confirming that success is not purely a function of financial and technical benefits, but is also influenced by institutional and cultural aspects. This research is aimed at defining why there is little geospatial data sharing between authorities in Saudi Arabia, and then presenting a workable model as a pilot arrangement. This should take into account issues raised in reference material; issues evidenced through experience in the implementation of systems that were configured as independent structures; issues of culture; and issues apparent in a range of existing data sharing arrangements. The doubts expressed by engineering managers towards using a geospatial database that is shared between institutions in Saudi Arabia have been borne out by the complexity of interrelationships which this research has revealed. Nevertheless, by concentrating on a two party entry level, a model has been presented which shows promise for the implementation of such a scheme. The model was derived empirically and checked against a case study of various other similar ventures, with a consideration of their applicability in the environment of Saudi Arabia. This model follows closely the generic structure of the Singapore Land Hub. The scalability of the model should allow it to be extended to other, multi-lateral data sharing arrangements. An alternative solution could be developed based on a Spatial Data Infrastructure model and this is suggested for ongoing investigation. Major unresolved questions relate to cultural issues, whose depth and intricacy have the potential to influence the realization of successful geospatial data sharing in the Kingdom of Saudi Arabia.
10

Assessing the Impacts of Sea Level Rise in the Caribbean using Geographic Information Systems

Sim, Ryan January 2011 (has links)
Numerous studies project that climate change will accelerate the rise in global sea levels, leading to increased coastal inundation, greater potential damage from storm surge events, beach erosion and other coastal impacts which threaten vital infrastructure and facilities that currently support the economies of island nations. There is a broad consensus amongst experts that small island developing states (SIDS) face the greatest risk to the projected impacts of climate change. Unfortunately, few sea level rise (SLR) impact assessment studies have been conducted in SIDS due to the limitations of the geospatial data with regard to currency, accuracy, relevance and completeness. This research improves upon previous SLR impact assessment research by utilizing advanced global digital elevation models to create coastal inundation scenarios in one metre increments for 19 Caribbean Community (CARICOM) nations and member states, and then examine the implications for seven key impact indicators (land area, population, economic activity, urban areas, tourism resorts, transportation infrastructure and beach erosion). The results indicate that a one metre SLR would have serious consequences for CARICOM nations. For example under this scenario over 10% of the 73 identified study area airports and 30% of the 266 major tourism resorts were identified as prone to flooding. Projected effects were not found to be uniform across the region; low-lying island nations and mainland countries with coastal plains below ten metres were identified as the most vulnerable countries. Recommendations for adaptive actions and policies are provided.

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