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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.
51

A methodology for assessing geographical information science professionals and programmes in South Africa

Du Plessis, Hendrik Jacobus 04 1900 (has links)
ENGLISH ABSTRACT: There is a growing demand worldwide for geographical information science (GISc) practitioners. Government agencies and the private sector are competing to find and employ practitioners in the GISc field who are suitably qualified and competent in the practice of the relevant technologies and sciences. Little research exists in South Africa on what GISc professionals should know or be able to do. A set of competencies, knowledge and skills required by professionals in the workplace is needed to design appropriate programmes and to guide those responsible for controlling quality in the profession (through registration) as well as in educational institutions (through accreditation). This research developed a new GISc academic framework with an embedded competency set to serve as a standard for the training of professional GISc practitioners. The format of this GISc framework is based on the structure of the University Consortium of Geographical Information Science (UCGIS) geographical information science and technology (GI S&T) body of knowledge (BoK) as the most frequently used framework internationally, but incorporates content from two existing South African competency sets. The new framework represents the South African, the USA and European perspectives of the knowledge and skills regarded as essential for the GISc profession. An easy-to-use and accessible web-based GISc self-assessment tool (SAT) was developed to facilitate the implementation and adoption of the new framework. Based on feedback from the GISc community the tool is proving to be a valuable labour- and time-saving resource with significant benefits to the GISc society and academia. The new GISc framework, which consists of 14 knowledge areas, 6 fundamental and 32 core units, was developed using a combination of qualitative and quantitative procedures to compare three different existing competency sets. This methodology is unique and lends itself for application in similar studies regardless of the discipline. Through the literature studied, no other GISc web-based SAT was discovered, making the concept of a web-based and database driven SAT unique. The SAT can be modified for use in other disciplines and countries. / AFRIKAANSE OPSOMMING: Daar is ’n groeiende vraag wêreldwyd na geografiese inligtingswetenskap (GIW) praktisyns. Regeringsagentskappe en die privaatsektor kompeteer om GIW praktisyns, wat in die toepassing van die relevante tegnologie en wetenskappe voldoende gekwalifiseerd en kundig is, te vind en in diens te neem. Min navorsing is in Suid-Afrika gedoen oor wat ʼn GIW professionele persoon moet weet en kan doen. ʼn Stel vaardighede en kennis wat van professionele persone in die werksomgewing vereis word, word benodig om gepaste opleidingsprogramme te ontwerp en om diegene wie verantwoordelik is vir die kwaliteitskontrolering van die beroep (deur registrasie) en opvoedkundige instansies (deur akkreditasie) te lei. Hierdie navorsing het ’n nuwe raamwerk en stel vaardighede vir GIW ontwikkel, wat kan dien as ʼn standaard vir die opleiding van professionele praktisyns in GIW. Die formaat van hierdie GIW-raamwerk is op die University Consortium of Geographical Information Science (UCGIS) geographical information science and technology (GI S&T) body of knowledge (BoK) gebaseer wat tans internasionaal as die mees gebruikte raamwerk aangewend word. Die nuwe raamwerk is ’n kombinasie van twee Suid-Afrikaanse kundigheidstelle en die GI S&T BoK. Dit verteenwoordig die Suid-Afrikaanse sowel as die Amerikaanse en Europese perspektiewe oor watter kennis en vaardighede vir die GIW professie belangrik geag word. ’n Webgebaseerde selfevalueringsinstrument (SEI) is ontwikkel om die implementering en aanvaarding van die raamwerk te bevorder. Die SEI is gebruikersvriendelik en toeganklik vir potensiële gebruikers. Terugvoering vanaf die GIW gemeenskap het bevestig dat die SEI (GISc SAT) ‘n waardevolle arbeid- en tydbesparende hulpbron is wat aansienlike voordele vir die GIW-gemeenskap en akademiese wêreld bied. Die nuwe GIW raamwerk bestaande uit 14 kennisgebiede, 6 fundamentele eenhede en 32 kern eenhede, is ontwikkel deur van kwalitatiewe en kwantitatiewe metodes gebruik te maak om verskillende GIW-raamwerke te vergelyk. Hierdie metodologie is uniek en kan ook in ander velde aangewend word. Tydens die literatuurstudie is geen ander GIW SEI opgespoor nie, wat die konsep van ʼn webgebaseerde en databasisgedrewe SEI uniek maak. Die SEI kan aangepas word vir gebruik in ander dissiplines en lande.
52

Evaluation of geospatial data to characterise upland water vole Arvicola terrestris habitat at Grains in the Water and Swains Greave in the Peak District, Derbyshire

Millin, Gail January 2003 (has links)
Evaluation of aerial photographs, LiDAR imagery and GPS survey points was conducted to characterise water vole habitat at Grains in the Water and Swains Greave, in the Peak District. Justification for the study is to explore an affective way to monitor water vole habitat in relation to water vole signs utilising GIS. The water vole is a rapidly declining native species (Strachan and Strachan, 2003). The geospatial data was evaluated in terms of integration and extraction. The aerial photography provided a basis for vegetation mapping after visual interpretation. The aerial photograph required geometric correction and an average control point RMSE of 4.17m for the Grains in the Water site, using a 2nd order polynomial model was achieved. Extraction of slope, aspect, stream proximity and elevation were achieved using LiDAR imagery. Pearson’s product moment correlation coefficient highlighted a significant relationship between water vole latrine density with slope at the 0.01 significance level for 4m and 6m resolution data (Grains in the Water). The Swains Greave site supported this result with a 0.01 significance level for 6m resolution slope data. Elevation and aspect did not show a significant correlation with latrine density at Grains in the Water. The main conclusion is that water vole habitat cannot be solely characterised by aerial photography and LiDAR data, as other habitat variables could affect water vole distributions, which cannot be extracted from these geospatial data e.g. pH, bank exposure and stream depth.
53

Geographical Information Technologies for Road Infrastructure Maintenance in Uganda

Kayondo-Ndandiko, Lydia Mazzi January 2011 (has links)
This thesis is a documentation of research on Geographical Information Technologies (GITs) as decision support tools in Road Infrastructure Maintenance (RIM) in Uganda. The main objective is to develop an operational framework within which the use of geo-information technologies can be enhanced as decision support tools in road infrastructure maintenance works of Uganda. Specifically, the research identifies the gaps and limitations in the use of and access to GITs for RIM and defines an algorithmic framework to accentuate the use of GITs in RIM. The research undertook a participatory multifaceted approach that included a review of documentation both in academia, in form of articles, journals, books, reports and research theses and also reports and documents prepared by the road infrastructure maintenance sector. Participant observations, field visits and measures, interviews and workshops were also triangularly employed to obtain the inherent answers. Content and GIS analyses were made to arrive at the findings that are documented in the papers which are part of the thesis. The gaps to using GITs in RIM have been found to include the lack of standardized datasets to address key nation-wide and local maintenance requirements, challenges on coordinating how geospatial data are acquired and utilized and the collection of duplicate data sets at the local and national levels. Also, the present institutional arrangements do not permit the formation of lasting partnerships and operating under a coordinated GIS infrastructure. The limitations to access of GITs in the sector include; the absence of policies for accessibility and standard use of GITs, lack of infrastructure to support utilization of geographic datasets, unavailability of and limited accessibility to geographic data, lack of geospatial capacity at individual and organizational levels and the digital divide. A nondeterministic algorithmic framework approach to the accentuation of GIT usage in RIM has been suggested. This framework involves strategies on; developing a policy on data collection guidelines emphasizing the use of GPS, satellite imagery and GIS, continuous undertaking of capacity building in the benefits of GIT use and the science involved, establishment of Local Spatial Data Infrastructures (LSDI) for road maintenance data and setting aside yearly budgets for the defined activities. In this framework, the dynamic segmentation data model is considered a superior data storage strategy for road maintenance data within the GIS. Dynamic Segmentation is the process of transforming linearly referenced data (also known as events) that have been stored in a table into features that can be displayed, queried and analyzed on the map through computations. It allows for the location of multiple events stored with linearly referenced attributes without any duplication with route geometry and in effect supports sharing of network infrastructure with different applications
54

Drawing Boundaries and Revealing Language Attitudes: Mapping Perceptions of Dialects in Korea

Jeon, Lisa 05 1900 (has links)
Perceptual dialectology studies have shown that people have strong opinions about the number and placement of dialect regions. There has been relatively little research conducted in this area on Korean, however, with early studies using only short language attitude surveys. To address this gap in research, in the present study, I use the 'draw-­?a-­?map' task to examine perceptions of language variation in Korea. I ask respondents to draw a line around places in Korea where people speak differently and provide names, examples, and comments about the language spoken in those areas. With the resulting data, I use ArcGIS 10.0 software to quantitatively identify, aggregate, and map the most salient dialect areas and categories for subjects' perceptions. I also perform a content analysis of the qualitative data provided by respondents using 'keywords.' During this process, I categorize comments and labels given by respondents to find emerging themes. Finally, I stratify perceptions of respondents by demographic factors, e.g., age, sex, and urbanicity, that have often been found to be important in language variation and change. An analysis of these data suggests that Koreans' perceptions of dialect regions are not necessarily limited by administrative boundaries. In fact, the data reveal not only perceptions of dialect variation unassociated with geographic borders, but they also tap into the way people connect ideas about language and place. Results from this study have implications for language attitudes research, perceptual dialectology methodology, and the relationship between language and place in Korea.
55

Using information and communications technology to improve the efficiency and accuracy of a utility's network data collection business process

Van Olst, Rex 15 February 2007 (has links)
Student Number : 0063608J - MSc(Eng) dissertation - School of Electrical and Information Engineering - Faculty of Engineering and the Built Environment / “You can see the computer age everywhere except in the productivity statistics”. This offhand remark by Robert Solow, the Nobel prize-winning economist [1] has stimulated many other economists to conduct more rigorous analyses on the impact of information technology on productivity. The research presented in this dissertation has been conducted on a large telecommunications utility. An important business process of the utility, that of collecting information on its geographically dispersed network assets, was automated using mobile computing and wireless technologies. The research compared this newly developed automated process with the current, manual, process of sourcing the field network asset data using paper-based templates, and capturing the data manually from the templates. The results of the pilot for this automated business process were encouraging and demonstrated an improvement of over 50% in the productivity of the data collection process, and its integrity. An important aspect of the research outlined in this dissertation was to design and implement the mobile computer-based electronic data collection prototype to minimise user obstruction to the technology deployed. The prototype was tested for technology acceptance by the targeted field workers. This test also proved successful. The research demonstrated that an improvement in productivity of over 50% was achievable from a well-considered investment in information technology. The results from the research also pointed the way for the deployment of this data collection solution in other utilities, e.g. electricity distribution, water reticulation, and municipalities. Through user prototype tests and a cultural intervention process on the targeted users (field workers), the research also demonstrated how the automated business process can be geared for use by low-skilled field workers, so important to improve productivity in developing economies such as those in Africa.
56

Geoprocessamento e sensoriamento remoto como ferramentas na gestão ambiental de Unidades de Conservação: o caso da Área de Proteção Ambiental (APA) do Capivari-Monos, São Paulo-SP. / Geographical Information System and Remote Sensing as tools for conservation units environmental management: Capivari-Monos Environmental Protection Area case (São Paulo-SP).

Jacintho, Luiz Roberto de Campos 20 March 2003 (has links)
Um quadro diagnóstico da Área de proteção Ambiental(APA) do Capivari Monos foi elaborado com informações produzidas através da aplicação de geoprocessamento e sensoriamento remoto. Essa Unidade de Conservação se localiza no extremo sul do município de São Paulo, onde ainda existem importantes fragmentos de Mata Atlântica e mananciais hídricos estratégicos para a Região Metropolitana de São Paulo . Um Mapa Geomorfológico foi produzido com o apoio de um Modelo Numérico de Terreno. Com a aplicação de Álgebra de Mapas, foram integrados os dados sobre Geotecnia e Geomorfologia e um mapa de Fragilidade do Meio Físico foi elaborado. As condições de hidrografia e relevo apontaram indícios de movimentação tectônica recente na região. Imagens dos Satélites Landsat-5 e Landsat-7 foram comparadas, com o emprego de técnicas de detecção de mudanças, para a quantificação do desmatamento no período entre 1991 e 2000. As imagens do satélite Landsat-7 foram classificadas, através do método supervisionado por regiões, para produção de um mapa temático de Uso do Solo e Cobertura Vegetal. Os resultados foram quantificados por sub-bacias hidrográficas, compondo um quadro comparativo que se destina a subsidiar a gestão ambiental da APA. Esses resultados mostram que o crescimento da ocupação urbana se concentra na bacia da Billings, principalmente na subbacia da Cratera de Colônia, onde a fragilidade do meio físico foi considerada muito alta. / Through the application of Geographical Information System and Remote Sensing it was elaborated a chart diagnosis for Capivari-Monos Environmental Protection Area. This Conservation Unit is located in the south end of São Paulo city where important Atlantic Forest fragments and strategic water spring still exist. With the support of a Digital Terrain Model it was produced a Geomorphologic map. Applying Map Algebra the data on Geothecnics and Geomorphorlogy had been integrated for mapping the fragility of physical environment. Relief and hidrography conditions pointed indications of neotectonic movements in this region. Employing change detection techniques in Landsat-7 images the deforestation between 1991 and 2000 was evaluated. A land use and land cover map was produced trough Landsat-7 image classification ( supervised per region method). The results show that the urban growth concentrates on the basin of Billings, mainly at the Cratera de Colônia sub-basin where the fragility regarding to phisical environment was considered very high.
57

Fragmentação florestal e prioridades para a conservação da biodiversidade / Forest fragmentation and biodiversity conservation priorities

Torezan, José Marcelo Domingues 06 March 2004 (has links)
Um modelo dedicado ao planejamento da conservação e restauração de habitats deve incluir informações estratégicas para assegurar a eficácia e de fácil obtenção, para assegurar a agilidade necessária. Planos e estratégias para conservação usualmente são complexos e demandam informações detalhadas, difíceis de se obter, como inventários biológicos e certos tipos de mapeamento, o que traz limitações em termos de disponibilidade, qualidade e custo das informações. Assim, procurou-se testar a eficiência de métodos simples para a seleção, em escala local, de áreas prioritárias para conservação de habitats fortemente fragmentados e reduzidos, uma situação comum no sul do Brasil, usando dados de imagens LANDSAT e planos de informações disponíveis em mapeamentos comuns, e trabalho de campo. Inicialmente analisou-se a estrutura da paisagem e o padrão de fragmentação em parte da região norte do estado do Paraná, e testar se tamanho e forma são adequados para selecionar os fragmentos florestais mais importantes para a conservação, ou seja, as que contribuem para manter maior quantidade e melhor qualidade de habitats, bem como tenham maior impacto (positivo) na conectividade e em outras variáveis da paisagem. Os resultados mostram que a floresta madura cobre cerca de 3% da paisagem, e a cobertura florestal total atinge perto de 8%, consistindo principalmente de pequenos fragmentos (82% tem entre 1 e 10 ha). Fragmentos grandes (>100 ha) são apenas 1,4% dos remanescentes, mas somam 34% da área de floresta. Apesar de estarem sujeitos a efeitos de borda em toda ou quase toda a sua área, fragmentos pequenos mostraram ter um papel importante na conectividade da paisagem. Numa área maior, foi feita uma pré-seleção de áreas com potencial para estabelecimento de redes de conservação. A pré-seleção procurou responder às seguintes perguntas: 1-Quais são os sítios com maior potencial para a conservação da biodiversidade? 2-Quais são os sítios sob maior risco para objetivos de conservação? e 3-Quais sítios têm melhores oportunidades para o estabelecimento de zonas de conservação de uso múltiplo? Foi identificado um conjunto de 11 fragmentos pertencendo a 5 sub-regiões, sofrendo variados graus de pressão antrópica. Adicionalmente, usando medidas simples de estrutura da paisagem, relacionadas com tamanho, forma e conectividade dos fragmentos, procurou-se identificar tipos estruturais de fragmentos, como uma forma alternativa para auxiliar o estabelecimento de prioridades para conservação a partir do seu papel, efetivo ou potencial, na paisagem. Foram identificados 5 tipos de fragmentos, pequenos (ilhotas isoladas, trampolins), médios (núcleos auxiliares e corredores) e grandes (núcleos principais), que podem ser usados para subsidiar estratégias de conservação. Utilizando informações sobre a estrutura da paisagem, hidrografia e legislação ambiental, propõe-se aqui uma estratégia de conservação para o complexo das bacias dos ribeirões Apertados-Três Bocas (CATB), ordenando atividades de restauração e conservação de fragmentos florestais, criação e expansão de unidades de conservação, além da proposição de formas de uso do solo compatíveis com o entorno de unidades de conservação. / Models dedicated to habitat conservation, management and restoration planning must include information both strategic, to ensure effectiveness, and of easy collection, to ensure agility. Plans and strategies for conservation usually are complex and demand detailed data, such as biological inventories and fine scale mapping, which limits work due to information availability, quality and cost. Hence, as a first approach, we tested the efficacy of a simple methods for selection, in local scale, of conservation sites in strongly fragmented landscapes, a common situation in southern Brazil, using LANDSAT data, common mapping data layers, and fieldwork. First, we analyzed landscape structure and fragmentation patterns in the northern portion of Paraná state, looking for the suitability of using size and shape of forest fragments for selection of most important sites for conservation, i.e. fragments that contribute to encompass large and of best quality forest areas, as well have higher positive impact on connectivity and overall landscape structure. Results show that mature forest cover near 3% of landscape area, with total forest cover reaching near 8%, mostly small fragments (82% between 1 and 10 ha). Large fragments (>100 ha) are only 1,4% of fragment number, but encompass 34% of forest area. In spite of suffering of edge effects in almost or all their area, small fragments showed an important role in landscape connectivity. In a larger area we did a pre-selection of suitable areas for establishing conservation networks. Such pre-selection were intended to answer the following questions: 1-What sites have higher biodiversity conservation potential? 2-What sites have higher threats to conservation goals? and 3-What sites have better opportunity to establish multiple-use conservation zones? A set of 11 fragments over 500 ha were selected, being part of 5 conservation sites, of varying degree of development pressure. Using simple landscape structure measures, such as size, shape and connectivity, we tried to identify structural types of habitat fragments, as an alternative way of fragment prioritizing. We identified 5 fragment types, small (stepping-stones and small isolated islands), mid-sized (auxiliary nuclei and corridors) and large (main nuclei), that can be used for landscape conservation strategies. Finally, using information about landscape structure, hidrography, human impacts and environmental legislation, we proposed a integrated conservation strategy for the Apertados-Três Bocas river basin complex (CATB), near Londrina city, encompassing ordination of restoration activities, establishment of new conservation units and expansion of existing ones, as well as proposing land uses compatible with conservation goals.
58

Caracterização geotécnica do subsolo de Curitiba para o planejamento de ocupação do espaço subterrâneo / Geotechnical characterisation of Curitiba city, southern Brazil, for planning of underground space

Talamini Neto, Edmundo 11 January 2002 (has links)
Devido ao seu crescimento acelerado o município de Curitiba deverá, em breve, ter seu espaço subterrâneo ocupado com maior intensidade. Este processo deve ser devidamente planejado, levando-se em conta as propriedades geotécnicas do subsolo. Assim, buscou-se desenvolver e aplicar um método de caracterização geotécnica do meio urbano para fins de planejamento do espaço subterrâneo. O trabalho consistiu no mapeamento tridimensional das principais unidades geotécnicas e na sua caracterização em termos de adequação para obras subterrâneas. Para tanto, inicialmente, reuniu-se dados geotécnicos existentes (sondagens, poços, mapas topográficos), e levantou-se pontos em campo. A partir do mapa topográfico gerou-se imagens artificiais do terreno, que foram reunidas aos demais dados em um sistema de informações geográficas (SIG). Este processo permitiu a elaboração de um mapa geológico simplificado. Os dados armazenados no sistema (SPT, profundidades das unidades geológicas, entre outros) passaram por uma filtragem, sendo exportados para a realização de análises geoestatísticas, interpolações e geração de cartas de isovalores. Grades regulares com valores interpolados foram então inseridas no SIG, constituindo-se um modelo geotécnico digital tridimensional que permite a navegação virtual entre unidades geotécnicas. Através de classificação geomecânica determinou-se as condições de suporte e estabilidade para possíveis túneis em rochas do município. No caso dos solos realizaram-se análises limite considerando informações de campo e ensaios SPT. Integrando- e, em um único documento, cartas de profundidade das unidades geotécnicas, o mapa geológico simplificado e informações construtivas para túneis, gerou-se um mapa orientativo para a construção de obras subterrâneas no município de Curitiba. Este mapa pode ser diretamente aplicado no planejamento de ocupação do subterrâneo. / Due to its fast population increase, the city of Curitiba will soon have to use its underground space. However, underground space use should be previously planned, taking geotechnical information into consideration. Therefore, the present research is intended to develop and apply an urban geotechnical characterisation method for underground space planning. The work consisted of a 3D mapping of main geotechnical units and determination of their suitability for underground constructions. At first, existing geotechnical data, such as borehole logs, well logs and topographic maps, have been collected and stored. Field studies were carried out subsequently. Digital terrain models have been obtained from topographic maps, and integrated with the other data in a geographical information system (GIS). This process allowed for the production of a simplified geological map. The stored data have been filtered and exported for the development of geostatistical analysis, interpolations and contour maps. Interpolated grids were then reinserted in the GIS software, where a 3D digital geotechnical model has been produced, permitting virtual navigation through soil layers. Tunnel stability and support design evaluations have been performed by means of rock mass classifications. For soil tunnel stability and support assessments, field studies and N-SPT correlations have been used along with limit analysis. A decision support geotechnical map for underground constructions has been obtained by representing, in a single document: the simplified geological map, geotechnical unit depth contour charts, tunnel stability and support analysis results. This decision support map may be directly applied for underground space planning activities.
59

Aplicação de sensoriamento remoto e geoprocessamento para analisar a distribuição da malária na região do reservatório de Tucuruí-PA / Remote sensing and geoprocessing to analyze malaria distribution at the UHE Tucuruí-Pará region

Vasconcelos, Cíntia Honório 15 April 2004 (has links)
A malária é a mais importante doença tropical do mundo. Em muitos países, especialmente no continente africano, causa grandes prejuízos com custos médicos e dias de trabalho perdidos. O risco de contrair malária está relacionado a alterações ambientais causadas por atividades como construções de estradas, projetos de mineração, agricultura e irrigação, particularmente em áreas da região amazônica e sudeste asiático. Entre outras causas da expansão desta endemia no mundo, pode-se incluir as mudanças climáticas, desintegração dos serviços de saúde e movimentos migratórios. Em áreas onde a malária é endêmica, o monitoramento das larvas e de populações de mosquitos adultos é de grande importância para o controle da doença. Novas ferramentas são necessárias para este processo, dentre os quais, as técnicas de sensoriamento remoto e os sistemas de informação geográfica (SIG). Essas técnicas têm reduzido custos e tempo nas pesquisas epidemiológicas, pois são usadas em escala regional para identificar tipos de vegetação, alterações ambientais que podem favorecer a proliferação de vetores da doença. Dada à gravidade da malária na região amazônica, este trabalho tem por objetivo entender como os padrões de distribuição espacial dos casos de malária na região da Usina Hidrelétrica de Tucuruí-PA se relacionam com os padrões de ocupação da terra, induzidos por sua implantação. Foi utilizado um conjunto de dados que incluem imagens TM-LANDSAT5 e SAR-RADARSAT para o levantamento de uso da terra os municípios de Tucuruí, Novo Repartimento e Jacundá e também para monitorar a variação sazonal do reservatório da UHE de Tucurui, além de uma série histórica de dados de malária do período compreendido entre 1992 a 2001. Esses dados foram integrados e analisados por meio do software SPRING 3.6. Foi constatado que os municípios de Novo Repartimento e Tucuruí, por possuírem grandes áreas de contato com o reservatório, apresentaram maiores problemas com a malária e que a variação temporal da doença, nesta região, está relacionada com o ciclo do reservatório, com a precipitação e com a dinâmica da população. / Malaria is the most important tropical disease in the world. In many countries, specially in the African continent, malaria is responsible for huge economical losses with medical bills and absenteeism. Malaria risk relates to environmental change derived from road construction, mining activities, agriculture and irrigation mainly in forested areas such as Amazon region and southern Asia. Among the causes explaining the spread of this endemic disease in the world, one can include climatic changes, healthy service breakdown and migration. At malaria endemic areas, larva and mosquito monitoring is highly important for disease control. New tools however are needed such as remote sensing and geographical information system in epidemic areas. These techniques have been responsible for reducing the time and cost of epidemiological researches, since they are used in a regional scale for assessing environmental disturbance apt to spreading of malaria vectors. Due to the threat of malaria in the Amazon region, this research aims to understand the relationship between land use changes induced by UHE-Tucuruí construction and the spatial distribution of malaria incidence in the region. LANDSAT5-TM and RADARSAT-SAR images were used respectively for land use mapping at Tucuruí, Novo Repartimento and Jacundá municipality and for monitoring the seasonal variation of UHE Tucuruí reservoir flooded area. A historic series of malaria data acquired for the National Health Foundation between 1992 and 2001 was also used. These data were integrated and analyzed with the aid of the SPRING 3.6 software. It was determined that Novo Repartimento and Tucuruí with large areas bounded by the reservoir are more prone to malaria incidence and that the time change in the disease in this region is related to the hydrology and reservoir operation, as well as with the precipitation and population dynamic.
60

Geologic and geological assessment of Acid Mine Drainage and heavy metals contamination in the West Rand, Witwatersrand Basin, South Africa

Abegunde, Oluseyi Ayokunle January 2015 (has links)
Masters of Science / Over the years, South Africa has produced over 468 million tons of mine waste yearly, in which gold mining waste accounted for 221 million tons (47%) of all mine waste produced, making it the largest, single source of waste and pollution. The exposure of these mine wastes such as tailings dams, waste rocks to oxidation and leaching has been the source of heavy metal release into the environment. This study assessed the magnitude of possibly leachable metals, its distribution and associations and predicted the AMD load discharge over time, from Mogale’s tailings dam into the environs in Randfontein area, Witwatersrand Basin, South Africa. Fifty-one tailings dam samples were analysed for their mineral and multi-elements contents. Petrography studies was done by X-Ray Diffraction (XRD) technique to determine the mineralogical composition. X-ray fluorescence (XRF) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) techniques were used to determine the multi-elements content in the tailings dam samples. The dataset were evaluated using multivariate statistics, Geographical Information Systems (GIS) and geochemical mass balance techniques. From the results, the tailings dam lithology was grouped into four distinct layers. The uppermost oxidized layer is siliceous and contains the highest SiO2 (87.32%) contents, which is with the lowest contents in Tot/S, U, As, Zn, Ni, Co, and Cu. A downward decrease in SiO2 (76.39%) contents occurs, coupled by an increase in Fe2O3, Tot/S, U, As, Zn, Ni, Co, and Cu, reaching maximum contents in layer 3. Layer 4 is the least weathered horizon. The cluster analysis grouped the samples into four sub-clusters based on the variation in SiO2 and Al2O3 contents. Factor analysis (83.542% total data variance) related the four controlling factors of element distribution to the occurrence in ore elements (sulphides), silicates, mining additives and refractory minerals. Elements of the same origin show a similar concentration trend down hole in the GIS interpolation analysis. The geochemical mass balance showed variable gain and loss of oxides and trace elements within each layer. Based on the variation patterns of the Tot/S contents and other mobile elements, about 0.164kg/tonne/yr(±0.02) of the tailings materials are leached yearly. Layer 1 is the most altered. This assessment and prediction study therefore gives an insight to the geochemical behaviour of an abandoned tailings dam, highlighting its extent of oxidation. However, the interaction between the oxidized zone and transition zone should be given more attention, to determine the actual extent of damage.

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