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

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.

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.

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.

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.

With the rapid advances in technologies, strategies for efficiently operating the spatial data are needed. The spatial data consists of points, lines, rectangles, regions, surface, and volumes. In this thesis, we focus on the region data. There are many important and efficient operations for the region data, such as neighbor finding, rotation, and mirroring. The nearest neighbor (NN) finding is frequently used in geographic information system (GIS). We can find the specific point (e.g., a park, a department store, etc.) that is the closest to our position in geographical information systems. In any representation for the region data, it is not instinctive and easy for nearest neighbor finding, since the coordinate information has been lost. Voros, Chen, and Chang have proposed the strategies for the nearest neighbor finding based on the quadtree in eight directions. Chen and Chang have proposed the nearest neighbor finding based on the Peano curves. These strategies for the nearest neighbor finding based on the quadtree and the Peano curve use a looping process, which is time-consuming. On the other hand, in recent years, many researchers have also focused on finding efficient strategies for the rotating and mirroring operations, which is useful when the animation is performed by computers. The boolean function-based encoding is a considerable amount of space-saving with respect to the other binary image representation. The CBLQ representation saves memory space as compared to the other binary image representations that have proposed the strategies of the set operations. However, the processes for obtaining the rotated or mirrored code based on these two representations are time-consuming, since the coordinate information of all pixels has been lost. Therefore, in this thesis, first, for the nearest neighbor finding based on the quadtrees and the Peano curve, we propose the strategy which uses the bitwise and arithmetic operations, and it is more efficient than the strategies based on the looping processes. Next, we propose efficient strategies for rotating and mirroring images based on the boolean function-based encoding and constant bit-length linear quadtrees (CBLQ) representations. From our simulation study, first, we show that our strategies based on the quadtree and the Peano curve require the least CPU-time and our strategy based on the Hilbert curve requires the least total time (the CPU-time + the I/O time) among the strategies for the nearest neighbor finding based on the quadtree and the three space-filling curves. Next, in most of cases, when the black density is no larger than 50%, the CPU-time based on the boolean function-based encoding is less than that based on CBLQ.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Este trabalho teve como objetivo principal analisar os parÃmetros hidrossedimentolÃgicos da bacia hidrogrÃfica do SÃo Josà (BHSJ), avaliar a produÃÃo de sedimentos e definir o mapa de susceptibilidade dos solos à erosÃo, a partir da EquaÃÃo Universal de Perdas do Solo (USLE). Para isso determinou-se: (i) a erosividade da chuva na bacia, a partir de formulaÃÃes desenvolvidas com base em Wischmeier e Smith (1958) e Fournier (1960); (ii) a erodibilidade do solo na bacia, desenvolvida a partir do nomograma de Wischmeier et al. (1971); (iii) o fator topogrÃfico da bacia, atravÃs do mÃtodo de Bertoni e Lombardi Neto (1990), utilizando o Modelo NumÃrico do Terreno (MNT) gerado atravÃs de dados do Shuttle Radar Topography Mission (SRTM); (iv) a identificaÃÃo, delimitaÃÃo e descriÃÃo dos tipos de uso e ocupaÃÃo dos solos na bacia, atravÃs de SIGs, utilizando a classificaÃÃo de imagens de satÃlite multitemporais prÃ-processadas. A razÃo de aporte de sedimentos (RAS) da bacia foi estimada a partir de equaÃÃes propostas por Maner (1958), Roehl (1962), Vanoni (1975), Renfro (1975) e Williams e Brendt (1972), a partir das quais escolheu-se a que apresentou resultado mais prÃximo do valor de descarga sÃlida em suspensÃo medido no exutÃrio para o ano hidrolÃgico monitorado de Setembro de 2011 a Setembro de 2012. Os resultados mostraram que: (i) a erosividade, determinada a partir da equaÃÃo desenvolvida nesse trabalho e validada com coeficiente de Nash e Sutcliffe de 0,81; apresentou resultados satisfatÃrios no ajuste da equaÃÃo da USLE para a BHSJ, com melhor ajuste dentre as metodologias comparadas, que apresentaram erros percentuais de pelo menos 50%. (ii) a erodibilidade determinada foi espacializada na bacia por Krigagem, utilizando modelo Gaussiano testado e validado; (iii) o fator topogrÃfico foi determinado e espacializado na bacia, considerando-se valores mÃdios para seis classes distintas de declividades; (iv) os tipos de uso e ocupaÃÃo dos solos na bacia foram divididos em agricultura, caatinga, cerrado, floresta Ãmida, solo exposto, Ãrea urbana e vegetaÃÃo rasteira. A partir da USLE estimou-se uma taxa de erosÃo na bacia de 364 t.ha-1.ano-1, correspondendo a uma produÃÃo de 1,48 x 106 t de sedimentos no ano hidrolÃgico. O mapa de susceptibilidade à erosÃo mostrou que a bacia apresentou grau de erosÃo: baixo, mÃdio, alto e muito alto, respectivamente, em 26,39, 34,34, 30,37 e 8,90% da Ãrea. A SDR determinada pelas equaÃÃes propostas por Maner (1958) e Vanoni (1975) apresentaram valores bem prÃximos da descarga sÃlida em suspensÃo medida no exutÃrio durante os eventos monitorados, com erros percentuais de â12,4 e â 2,6%, respectivamente. / This study aimed to analyse the SÃo Josà river catchment (BHSJ) hydrosedimentological parameters, evaluate the sediment yield and define the susceptibility of soils to erosion based on the Equation Universal Soil Loss (USLE). Therefore, it was determined: (i) the rainfall erosivity (R - factor) at catchment, based on the formulations proposed by Wischmeier and Smith (1958) and Fournier (1960), (ii) the soil erodibility (K â factor) at catchment, it was calculated using the nomograph developed by Wischmeier et al. (1971), (iii) the topographic factor (LS â factor) was obtained through the method of Bertoni and Lombardi Neto (1990), using the Digital Elevation Model (DEM) generated by the Shuttle Radar Topography Mission (SRTM), (iv) identification, delineation and description of the land cover (C â factor), using GIS, through by the classification techniques of multitemporal satellite images. The sediment delivery ratio (SDR) of the catchment was estimated based in equations proposed by Maner (1958), Roehl (1962), Vanoni (1975), Renfro (1975) and Williams and Brendt (1972). The equation that presented the best fit was selected, comparing modelled and measured data at the catchment outlet, for hydrological year monitored since September 2011 to September 2012. The results show the following: (i) the rainfall erosivity, determined by the equation developed in this study and validated with Nash and Sutcliffe coefficient of 0.81; presented satisfactory results in the adjustment of the USLE equation for BHSJ, with best adjustments among the compared methods, that presented percentage errors of at least 50%; (ii) the soil erodibility determined was spatialized in the catchment by Kriging, using the method of interpolation Gaussian model tested and validated; (iii) the topographic factor was determined and spatialized in the catchment, considering average values for six distinct classes of slopes; (iv) the use types and occupation of the basin were divided into agriculture, caatinga, cerrado, tropical rainforest, bare soil, urban and undergrowth. In the catchment, the rate of erosion was estimated at 364 t ha-1.year-1 from the USLE, corresponding to a sediment yield of 1.48 x 106 t in the hydrological year. The map of erosion susceptibility showed that the degree of erosion basin presented: low, medium, high and very high, respectively, 26.39, 34.34, 30.37 and 8.90% of the area. SDR determined by the equations proposed by Maner (1958) and Vanoni (1975) presented values near suspended sediment discharge measured at the catchment outlet during the monitored events, with percentage errors of -12.4 and -2.6%, respectively.

Flash flooding, as a result of excessive rainfall in a short period, is considered as one of the worst environmental hazards in arid regions. Areas located in the western provinces of Saudi Arabia have experienced catastrophic floods. Geomorphologic evaluation of hydrographic basins provides necessary information to define basins with flood hazard potential in arid regions, especially where long-term field observations are scarce and limited. Six large basins (from North to South: Yanbu, Rabigh, Khulais, El-Qunfza, Baish and Jizan) were selected for this study because they have large surface areas and they encompass high capacity dams at their downstream areas. Geographic Information System (GIS) and remote sensing techniques were applied to conduct detailed morphometric analysis of these basins. The six basins were further divided into 203 sub-basins based on their drainage density. The morphometric parameters of the six basins and their associated 203 sub-basins were calculated to estimate the degree of flood hazard by combining normalized values of these parameters. Thus, potential flood hazard maps were produced from the estimated hazard degree. Furthermore, peak runoff discharge of the six basins and sub-basins were estimated using the Snyder Unit Hydrograph and three empirical models (Nouh’s model, Farquharson’s model and Al-Subai’s model) developed for Saudi Arabia. Additionally, recommendations for flood mitigation plans and water management schemes along these basins were further discussed.

In developing countries rural communities are normally geographically isolated contributing to both poverty levels and the deficiency in the participation of social and economic activities. Accessibility to education constitutes one of the primordial links between the economic growth of a country and the development of high skilled population. Given South Africa's unique history, divisions throughout the landscape incapacitate inhabitants of rural communities in reaching opportunities and services, therefore, aggravating issues related to social exclusion and inequality. This study aims to determine accessibility levels in South African rural regions by looking at different aspects that entangle the theory behind it, specifically: the zone attractiveness and impedance. With that in mind, the investigations carried out are firstly directed towards accessibility at the provincial level and thereafter a focus area is determined. At the provincial level, it was found that the Northern Cape presented the greatest disadvantages. However, given insufficient resources and data related to this province, the Cape Winelands Municipality District was chosen as the area to extend the investigations. When assessing the focus area, the study deployed a GIS-based analysis wherein potential and real accessibility were determined. Initially using the gravity measure, and subsequently using a survey carried out in the region. The study has revealed that Stellenbosch and Robertson are the towns experiencing high accessibility levels. Notwithstanding, most principal towns still experience critically low accessibility indexes. The findings of this study can, therefore, be useful in indicating areas that need further studies or are experiencing disadvantages regarding accessibility.

Harmful Algae Blooms (HABs) in inland waterbodies (e.g., lakes and ponds) pose serious threat to human health and natural ecosystem. Thus, it is imperative to assess HABs and their potential triggering factors over broader spatiotemporal scales. This study utilizes Chlorophyll-a (Chl-a) concentration in water samples collected from lakes in Illinois as an indirect measurement of HABs. The major objectives were to assess the spatiotemporal pattern of HABs over Illinois regions in recent decades, and to examine different machine learning models for predicting the Chl-a concentration based on publicly available water quality datasets. The Chl-a dataset was compiled from two different sources, the regular monitoring program by Illinois Environmental Protection Agency (IEPA) and the Voluntary Lake Monitoring Program (VLMP), the latter of which was primarily collected by citizen participants. Seven environmental and water quality zones were selected for spatial analyses. Additionally, the temporal patterns were assessed using time-series decomposition of monthly Chl-a concentration datasets. The machine learning pipeline includes two tasks: a regression modeling task for predicting Chl-a concentration, and a classification task for estimating lake trophic status. Different meteorological, land use and land cover, and lake morphometry variables were used as independent variables. Four regression models, i.e., Partial Least Squares Regression (PLSR), Support Vector Machine Regression (SVR), Artificial Neural Network Regression (ANNR), and Random Forest Regression (RFR) were used for the first task of the modeling pipeline, and four classification models, i.e., Logistic Regression Classification (LRC), Support Vector Machine Classification (SVC), Artificial Neural Network Classification (ANNC), and Random Forest Classification (RFC), were used for the second task. Results indicate that: a) the Collinsville region in southwestern part of Illinois exhibited higher mean concentration of Chl-a in its lakes than any other regions from 1998 to 2018; b) the lakes that showed increasing trends in their monthly mean Chl-a concentrations were also clustered in the southwestern region; c) Random Forest outperformed all other models in both classification (Accuracy=60.06%) and regression (R2=38.88%); and d) the land use and land cover variables were found as the most important set of variables in Random Forest models.