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Análise da estrutura da paisagem na bacia do Rio Corumbataí, SP. / Landscape structure analysis of the Corumbataí River Basin, SP.Roberta de Oliveira Averna Valente 06 December 2001 (has links)
A importância regional da Bacia do Rio Corumbataí para o abastecimento de água, em qualidade e quantidade, e o elevado nível de desmatamento que é na atualidade um dos fatores que mais afetam a sua biodiversidade, motivaram a análise da estrutura paisagem dessa área. Para essa análise foi produzido o mapa de uso e cobertura do solo da bacia e aplicados índices de ecologia da paisagem. O mapa de uso e cobertura do solo foi produzido pela classificação digital supervisionada (algoritmo de máxima verossimilhança) de imagens orbitais digitais (SPOT e LANDSAT ), com exatidão global de 91,10%.Os índices de ecologia da paisagem (calculados pelo software FRAGSTATS) foram determinados por sub-bacias (Passa-Cinco, Alto Corumbataí, Médio Corumbataí, Ribeirão Claro e Baixo Corumbataí), sendo utilizados os que fazem a caracterização em nível de fragmentos e em nível de classes de uso e cobertura do solo. Os índices referentes às classes forneceram as caracterizações das classes floresta nativa (Floresta Estacional Semidecidual) e cerrado; e os referentes a fragmentos a caracterização, dos seus respectivos remanescentes. As caracterizações quantitativas em nível de fragmentos e de classes de uso e cobertura do solo foram feitas com os grupos de índices de área; densidade, tamanho e variabilidade métrica; área nuclear; forma; proximidade; e dispersão e justaposição. Com base nesses índices, pode-se dizer que a estrutura florestal das sub-bacias do rio Passa-Cinco e Alto Corumbataí, apresentaram algumas diferenciações em relação às sub-bacias do Médio Corumbataí, do Ribeirão Claro, e do Baixo Corumbataí. Os índices indicaram que nas sub-bacias do Médio Corumbataí, do Ribeirão Claro, e Baixo Corumbataí, existe a predominância de fragmentos de floresta nativa menores que 15 ha e que seus fragmentos, independentemente do tamanho, estão mais distantes uns dos outros e, portanto, mais sujeitos às ações dos outros usos e coberturas do solo que os remanescentes das sub-bacias do Alto Corumbataí e do rio Passa-Cinco. Nas sub-bacias do rio Passa-Cinco, do Alto Corumbataí e do Ribeirão Claro, a estrutura florestal tem como outro componente a vegetação de cerrado. No Alto Corumbataí, essa vegetação representa 78,24% do total de cerrado da Bacia do Rio Corumbataí. Neste contexto, pode-se concluir que os índices de ecologia da paisagem, quando analisados em conjunto, permitiram a caracterização da estrutura florestal das sub-bacias da Bacia do Rio Corumbataí e a avaliação dessas áreas, sob o ponto de vista da preservação e da conservação florestal. Tendo por base a preservação e a conservação florestal, pode-se concluir que as sub-bacias do Passa-Cinco e Alto Corumbataí têm um padrão de estrutura florestal com predominância de fragmentos aptos à preservação. Essa condição é conseqüência do fato de possuirem fragmentos com área nuclear suficiente para manter sua estrutura interna e a estabilidade da estrutura florestal da paisagem em que estão inseridos. As sub-bacias do Ribeirão Claro, Baixo Corumbataí e, principalmente, do Médio Corumbataí, apresentam estrutura florestal com a maioria de fragmentos devendo ser conservados. Os fragmentos que possuem a área mínima necessária à autossustentabilidade não são suficientes, em número, para manter a estabilidade dessas paisagens. / Corumbataí River Basin is regionally important for public water supply. It presents a high deforestation level, which affects deeply its biodiversity. These facts have motivated the landscape structure analysis of this area, based on its land use/land cover map and landscape ecology indices. Land use/ land cover map was produced by supervised digital classification (maximum Likelihood algorithm) of satellite images (SPOT and LANDSAT), with an classification accuracy of 91.10%. Landscape ecology indices (calculated by FRAGSTATS software) were determined for each sub-basin (Passa-Cinco, Alto Corumbataí, Médio Corumbataí, Ribeirão Claro e Baixo Corumbataí), being used those that perform the characterization to the patch level and land use/land cover classes level. The classes quantified were: native forest (Seasonal Semidecidual Forest) and cerrado. The indices groups applied were: area; density, size and variability metrics; core area; shape; proximity; interspersion and juxtaposition index. Based on those indices one can assert that the forest structure of Passa-Cinco and Alto Corumbataí sub-basins showed some differences in relation to the other ones. Most of the native forest patches in the Médio Corumbataí, Ribeirão Claro e Baixo Corumbataí sub-basins are less than the native forest patches of the other two sub-basins. Other native vegetation class in the Passa-Cinco, Alto Corumbataí, and Ribeirão Claro sub-basins is the cerrado, mainly in the Alto Corumbataí (78.24% of the whole basin). The results of this research have indicated that the landscape ecology indices allowed the forest structure characterization of the Corumbataí River sub-basins and the evaluation of those areas according to the viewpoint of forest preservation and conservation. Most of the native forest patches in Passa-Cinco and Alto Corumbataí sub-basin should be preserved. This is a consequence of the fact of having core area big enough to maintain their internal structure and stability of forest structure in the landscape where they are. For the Ribeirão Claro, Baixo Corumbataí, and mainly Médio Corumbataí, most of the native forest patches should be conserved. Those patches do not have a core area able to sustain themselves.
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Detecção de mudanças no uso e na cobertura do solo em uma série temporal de imagens da Região da Campanha do Rio Grande do SulKiel, Roberto January 2008 (has links)
A detecção de mudanças no uso e na cobertura do solo pode ser considerada a função do sensoriamento remoto que agrega uma dimensão temporal à análise das informações contidas nas imagens. Ao confrontá-las duas a duas, para identificar, localizar e qualificar as transformações que ocorreram na cobertura e no uso do solo em determinados espaço e tempo, através das respostas espectrais registradas nos pares de pixels homólogos quando aplicados limiares que permitam distinguir entre a mudança e a não mudança. A análise ponto a ponto, ou instante a instante permite inferir sobre a quantidade e qualidade das mudanças detectadas em uma região durante um determinado período. Já a análise comparativa entre dois ou mais destes resultados, utilizando uma série temporal de imagens, permite inferir acerca da dinâmica das transformações em vários outros aspectos; como topologia, intensidade, tipo de mudança (substituição ou conversão) e taxa de mudança. São várias as técnicas disponíveis para a detecção de mudanças no uso e cobertura do solo a partir de imagens digitais, obtidas por sensores orbitais, dois grandes grupos podem ser propostos: técnicas de pré-classificação e de pós-classificação, diferindo fundamentalmente sobre quais produtos são aplicados os limiares da detecção das mudanças, se sobre produtos temáticos da classificação de imagens, ou se sobre imagens diretamente. Este trabalho utiliza técnicas de detecção baseadas em subtração de imagens de ambos os grupos, especificamente, a pós-classificação por máxima verossimilhança e da pré-classificação, por Índice de Vegetação por Diferença Normalizada (NDVI) e por Transformada Kauth-Thomas (KT), nesse caso o componente de verdor. Visa avaliar a sensibilidade e adequação destas técnicas para a análise das transformações ocorridas no uso e da cobertura do solo durante os dois períodos de comparação: 1988 a 2001 e 2001 a 2006 e no conjunto dos 18 anos, na captação das tendências das transformações deste ambiente da Campanha Sul do Estado do Rio Grande do Sul, que é majoritariamente rural, muito dinâmico e bastante heterogêneo. Considerando que durante o período abrangido neste trabalho, grandes fazendas tradicionais de pecuária, em um primeiro momento, foram convertidas para agricultura familiar através da criação intensiva de assentamentos da reforma agrária, ocorrida entre a metade dos anos 80 e a metade dos anos 90, mais recentemente, substituídas por plantios florestais da indústria do papel. Os resultados permitiram confrontar os tratamentos e verificar as acurácias das detecções e identificar as principais dificuldades, em especial, o efeito da fenologia nas diversas fases em que se apresentam nas substituições florestais de ciclos longos. A dificuldade da técnica KT, em lidar com plantios semi-perenes e perenes, a impossibilidade de se considerar áreas cobertas em algum momento por nuvens. Por fim, corrobora com a inviabilidade do estabelecimento a priori da melhor técnica, ou mesmo, daquela mais acurada, sem que sejam considerados plenamente os objetivos, a escala, a natureza do ambiente analisado e as classes de mudança estabelecidas para o trabalho, além da qualidade das imagens disponíveis. / The detection of alterations in land use and cover can be considered as being an operation in Remote Sensing which adds a time dimension to the analysis of information in images. This is done when images are compared, by groups of two, at certain space and time looking for spectral responses stored in pairs of homologous pixels, through the application of thresholds which lead to the differentiation between change and non-change. A point-to-point, or instant-to-instant analysis, permits to infer on the amount and quality of alterations detected in a region, during a certain period. The comparative analysis between two or more of these results, via a time series of images, informs on the dynamics of transformations in other aspects, as topology, intensity, kind of change (substitution or conversion), and change rate. Several techniques are available to detect alterations in land use and cover, from digital images collected by orbital sensors. Two larger groups can be highlighted: preclassification techniques, and post-classification techniques. They differ basically on over which products the thresholds defining changes are applied, these products being either thematic ones for image classification, or the image itself. This work uses detection techniques based on image subtraction of both groups. Pre-classification uses the Normalized Difference Vegetation Index (NDVI) and the Kauth-Thomas Transform (KT), the green index in this last case. Post-classification uses the Maximum Likelihood. The objective is to estimate the sensitivity and adequacy of these techniques for the detection and analysis of changes in land use and cover during two comparison periods: the first one is from 1988 to 2001; the second, from 2001 to 2006. Besides, the whole 18-years period is studied to detect tendencies of the transformation of the region. The study area is at the Campanha Sul region, at Rio Grande do Sul State Brazil. It is largely rural, heterogeneous and dynamic, since during the period covered (1988-2006) large estates where either converted into smaller properties, family-managed; though an intensive policy of agrarian reform (from the mid-eighties to the mid-nineties), or, more recently, by industrial-style cultures of forests to serve the paper industry. The results allowed comparing the different treatments and to verify the accuracy of detections. The main difficulties were the phonological cycles, the various phases of long-cycle artificial forests, the limitations of the KT technique to handle semi-perennial cultures, and cloud-covered areas. It was not possible to clearly define the better or more accurate technique; this definition depends of specific objectives, of the scale and nature of the study region, and of the classes of change being analyzed, besides of the quality of available images.
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Detecção de mudanças no uso e na cobertura do solo em uma série temporal de imagens da Região da Campanha do Rio Grande do SulKiel, Roberto January 2008 (has links)
A detecção de mudanças no uso e na cobertura do solo pode ser considerada a função do sensoriamento remoto que agrega uma dimensão temporal à análise das informações contidas nas imagens. Ao confrontá-las duas a duas, para identificar, localizar e qualificar as transformações que ocorreram na cobertura e no uso do solo em determinados espaço e tempo, através das respostas espectrais registradas nos pares de pixels homólogos quando aplicados limiares que permitam distinguir entre a mudança e a não mudança. A análise ponto a ponto, ou instante a instante permite inferir sobre a quantidade e qualidade das mudanças detectadas em uma região durante um determinado período. Já a análise comparativa entre dois ou mais destes resultados, utilizando uma série temporal de imagens, permite inferir acerca da dinâmica das transformações em vários outros aspectos; como topologia, intensidade, tipo de mudança (substituição ou conversão) e taxa de mudança. São várias as técnicas disponíveis para a detecção de mudanças no uso e cobertura do solo a partir de imagens digitais, obtidas por sensores orbitais, dois grandes grupos podem ser propostos: técnicas de pré-classificação e de pós-classificação, diferindo fundamentalmente sobre quais produtos são aplicados os limiares da detecção das mudanças, se sobre produtos temáticos da classificação de imagens, ou se sobre imagens diretamente. Este trabalho utiliza técnicas de detecção baseadas em subtração de imagens de ambos os grupos, especificamente, a pós-classificação por máxima verossimilhança e da pré-classificação, por Índice de Vegetação por Diferença Normalizada (NDVI) e por Transformada Kauth-Thomas (KT), nesse caso o componente de verdor. Visa avaliar a sensibilidade e adequação destas técnicas para a análise das transformações ocorridas no uso e da cobertura do solo durante os dois períodos de comparação: 1988 a 2001 e 2001 a 2006 e no conjunto dos 18 anos, na captação das tendências das transformações deste ambiente da Campanha Sul do Estado do Rio Grande do Sul, que é majoritariamente rural, muito dinâmico e bastante heterogêneo. Considerando que durante o período abrangido neste trabalho, grandes fazendas tradicionais de pecuária, em um primeiro momento, foram convertidas para agricultura familiar através da criação intensiva de assentamentos da reforma agrária, ocorrida entre a metade dos anos 80 e a metade dos anos 90, mais recentemente, substituídas por plantios florestais da indústria do papel. Os resultados permitiram confrontar os tratamentos e verificar as acurácias das detecções e identificar as principais dificuldades, em especial, o efeito da fenologia nas diversas fases em que se apresentam nas substituições florestais de ciclos longos. A dificuldade da técnica KT, em lidar com plantios semi-perenes e perenes, a impossibilidade de se considerar áreas cobertas em algum momento por nuvens. Por fim, corrobora com a inviabilidade do estabelecimento a priori da melhor técnica, ou mesmo, daquela mais acurada, sem que sejam considerados plenamente os objetivos, a escala, a natureza do ambiente analisado e as classes de mudança estabelecidas para o trabalho, além da qualidade das imagens disponíveis. / The detection of alterations in land use and cover can be considered as being an operation in Remote Sensing which adds a time dimension to the analysis of information in images. This is done when images are compared, by groups of two, at certain space and time looking for spectral responses stored in pairs of homologous pixels, through the application of thresholds which lead to the differentiation between change and non-change. A point-to-point, or instant-to-instant analysis, permits to infer on the amount and quality of alterations detected in a region, during a certain period. The comparative analysis between two or more of these results, via a time series of images, informs on the dynamics of transformations in other aspects, as topology, intensity, kind of change (substitution or conversion), and change rate. Several techniques are available to detect alterations in land use and cover, from digital images collected by orbital sensors. Two larger groups can be highlighted: preclassification techniques, and post-classification techniques. They differ basically on over which products the thresholds defining changes are applied, these products being either thematic ones for image classification, or the image itself. This work uses detection techniques based on image subtraction of both groups. Pre-classification uses the Normalized Difference Vegetation Index (NDVI) and the Kauth-Thomas Transform (KT), the green index in this last case. Post-classification uses the Maximum Likelihood. The objective is to estimate the sensitivity and adequacy of these techniques for the detection and analysis of changes in land use and cover during two comparison periods: the first one is from 1988 to 2001; the second, from 2001 to 2006. Besides, the whole 18-years period is studied to detect tendencies of the transformation of the region. The study area is at the Campanha Sul region, at Rio Grande do Sul State Brazil. It is largely rural, heterogeneous and dynamic, since during the period covered (1988-2006) large estates where either converted into smaller properties, family-managed; though an intensive policy of agrarian reform (from the mid-eighties to the mid-nineties), or, more recently, by industrial-style cultures of forests to serve the paper industry. The results allowed comparing the different treatments and to verify the accuracy of detections. The main difficulties were the phonological cycles, the various phases of long-cycle artificial forests, the limitations of the KT technique to handle semi-perennial cultures, and cloud-covered areas. It was not possible to clearly define the better or more accurate technique; this definition depends of specific objectives, of the scale and nature of the study region, and of the classes of change being analyzed, besides of the quality of available images.
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Detecção de mudanças no uso e na cobertura do solo em uma série temporal de imagens da Região da Campanha do Rio Grande do SulKiel, Roberto January 2008 (has links)
A detecção de mudanças no uso e na cobertura do solo pode ser considerada a função do sensoriamento remoto que agrega uma dimensão temporal à análise das informações contidas nas imagens. Ao confrontá-las duas a duas, para identificar, localizar e qualificar as transformações que ocorreram na cobertura e no uso do solo em determinados espaço e tempo, através das respostas espectrais registradas nos pares de pixels homólogos quando aplicados limiares que permitam distinguir entre a mudança e a não mudança. A análise ponto a ponto, ou instante a instante permite inferir sobre a quantidade e qualidade das mudanças detectadas em uma região durante um determinado período. Já a análise comparativa entre dois ou mais destes resultados, utilizando uma série temporal de imagens, permite inferir acerca da dinâmica das transformações em vários outros aspectos; como topologia, intensidade, tipo de mudança (substituição ou conversão) e taxa de mudança. São várias as técnicas disponíveis para a detecção de mudanças no uso e cobertura do solo a partir de imagens digitais, obtidas por sensores orbitais, dois grandes grupos podem ser propostos: técnicas de pré-classificação e de pós-classificação, diferindo fundamentalmente sobre quais produtos são aplicados os limiares da detecção das mudanças, se sobre produtos temáticos da classificação de imagens, ou se sobre imagens diretamente. Este trabalho utiliza técnicas de detecção baseadas em subtração de imagens de ambos os grupos, especificamente, a pós-classificação por máxima verossimilhança e da pré-classificação, por Índice de Vegetação por Diferença Normalizada (NDVI) e por Transformada Kauth-Thomas (KT), nesse caso o componente de verdor. Visa avaliar a sensibilidade e adequação destas técnicas para a análise das transformações ocorridas no uso e da cobertura do solo durante os dois períodos de comparação: 1988 a 2001 e 2001 a 2006 e no conjunto dos 18 anos, na captação das tendências das transformações deste ambiente da Campanha Sul do Estado do Rio Grande do Sul, que é majoritariamente rural, muito dinâmico e bastante heterogêneo. Considerando que durante o período abrangido neste trabalho, grandes fazendas tradicionais de pecuária, em um primeiro momento, foram convertidas para agricultura familiar através da criação intensiva de assentamentos da reforma agrária, ocorrida entre a metade dos anos 80 e a metade dos anos 90, mais recentemente, substituídas por plantios florestais da indústria do papel. Os resultados permitiram confrontar os tratamentos e verificar as acurácias das detecções e identificar as principais dificuldades, em especial, o efeito da fenologia nas diversas fases em que se apresentam nas substituições florestais de ciclos longos. A dificuldade da técnica KT, em lidar com plantios semi-perenes e perenes, a impossibilidade de se considerar áreas cobertas em algum momento por nuvens. Por fim, corrobora com a inviabilidade do estabelecimento a priori da melhor técnica, ou mesmo, daquela mais acurada, sem que sejam considerados plenamente os objetivos, a escala, a natureza do ambiente analisado e as classes de mudança estabelecidas para o trabalho, além da qualidade das imagens disponíveis. / The detection of alterations in land use and cover can be considered as being an operation in Remote Sensing which adds a time dimension to the analysis of information in images. This is done when images are compared, by groups of two, at certain space and time looking for spectral responses stored in pairs of homologous pixels, through the application of thresholds which lead to the differentiation between change and non-change. A point-to-point, or instant-to-instant analysis, permits to infer on the amount and quality of alterations detected in a region, during a certain period. The comparative analysis between two or more of these results, via a time series of images, informs on the dynamics of transformations in other aspects, as topology, intensity, kind of change (substitution or conversion), and change rate. Several techniques are available to detect alterations in land use and cover, from digital images collected by orbital sensors. Two larger groups can be highlighted: preclassification techniques, and post-classification techniques. They differ basically on over which products the thresholds defining changes are applied, these products being either thematic ones for image classification, or the image itself. This work uses detection techniques based on image subtraction of both groups. Pre-classification uses the Normalized Difference Vegetation Index (NDVI) and the Kauth-Thomas Transform (KT), the green index in this last case. Post-classification uses the Maximum Likelihood. The objective is to estimate the sensitivity and adequacy of these techniques for the detection and analysis of changes in land use and cover during two comparison periods: the first one is from 1988 to 2001; the second, from 2001 to 2006. Besides, the whole 18-years period is studied to detect tendencies of the transformation of the region. The study area is at the Campanha Sul region, at Rio Grande do Sul State Brazil. It is largely rural, heterogeneous and dynamic, since during the period covered (1988-2006) large estates where either converted into smaller properties, family-managed; though an intensive policy of agrarian reform (from the mid-eighties to the mid-nineties), or, more recently, by industrial-style cultures of forests to serve the paper industry. The results allowed comparing the different treatments and to verify the accuracy of detections. The main difficulties were the phonological cycles, the various phases of long-cycle artificial forests, the limitations of the KT technique to handle semi-perennial cultures, and cloud-covered areas. It was not possible to clearly define the better or more accurate technique; this definition depends of specific objectives, of the scale and nature of the study region, and of the classes of change being analyzed, besides of the quality of available images.
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Metodologia de classificação de imagens multiespectrais aplicada ao mapeamento do uso da terra e cobertura vegetal na Amazônia: exemplo de caso na região de São Félix do Xingu, sul do Pará. / Methodology for multispectral image classification applied to the mapping of land use and land cover in Amazonia: a case example in the region of Sao Felix do Xingu, south of Para.Fernando Shinji Kawakubo 05 August 2010 (has links)
Este trabalho apresenta uma metodologia de classificação de imagens multiespectrais aplicada a análise e mapeamento da evolução do uso da terra/cobertura vegetal em São Félix do Xingu, Sul do Pará. Imagens frações representando as proporções de sombra, vegetação e solo foram estimadas a partir das bandas 1 a 5 e 7 do Landsat-5 TM e relacionadas com as estruturas das classes de uso da terra/cobertura vegetal. As imagens frações geradas do modelo linear de mistura espectral foram importantes para reduzir a massa de dados e ao mesmo tempo realçar alvos de interesse na imagem. A banda do infravermelho próximo (TM-4) foi importante para realçar áreas de queimadas. A classificação adotada foi divida em etapas combinando técnica de segmentação por crescimento de regiões e uso de máscaras. Por meio da máscara foi possível restringir o processo de segmentação em regiões pré-estabelecidas com o intuito de adquirir um melhor particionamento da imagem. Adotando este procedimento, ao invés de realizar uma única segmentação para mapear todas as classes em uma única vez, foram realizadas várias segmentações ao longo das etapas. As regiões segmentadas foram agrupadas com um classificador não-supervionado batizado de ISOSEG. Os resultados mostram que a metodologia é bastante eficiente. A matriz de erro gerada para a classificação de 2008 apontou que as confusões mais freqüentes ocorreram entre as classes que apresentaram em certas localidades proporções de misturas parecidas: Capoeira e Campo/Pastagem-2; Campo/Pastagem-1 e Campo/Pastagem-2; Queimada-1 e Queimada-2; Solo Exposto e Campo/Pastagem-1. Considerando nove classes, o índice Kappa atingiu 0,58, o que representa um valor de concordância classificada como moderada. Quando o numero de classes foi reduzido para 6, agrupando as classes que apresentaram as maiores confusões, o índice Kappa subiu para 0,80, atingindo um valor de concordância quase perfeita. A comparação dos resultados das classificações de 1987, 1992, 2000 e 2008 juntamente com a analise de dados auxiliares permitiu traçar um modelo de evolução do desmatamento e do uso da terra para São Félix do Xingu. O intenso desmatamento observado principalmente a partir de 2000 foi relacionado com o incremento da atividade pecuária, sendo São Félix do Xingu o município que detém atualmente o segundo maior rebanho bovino do País. / In this work we present a methodological procedure for multi-spectral images classification to evaluate and map land-use and land-cover changes in São Félix do Xingu, Southern Pará (Brazilian Amazon). Fraction images representing shade, vegetation and soil abundance at the pixel scale were estimated using all six reflective bands of Thematic Mapper sensor (TM-1 to TM-5 and TM-7) and related to different types of land-use and land-cover classes. The linear spectral mixing analysis method was an alternative approach adopted to reduce the data-dimensionality while at the same time enhancing targets of interest. Also, the near-infrared band (TM-4) was employed to separate areas affected by burns (Queimadas in Portuguese). The classification routines were performed in stages by combining region-growing segmentation and use of masking techniques. For each stage, the segmentation process was directed to preselected areas by masking techniques in order to obtain a better image partitioning. This procedure resulted in more than one segmentation thereby reducing confusing errors during the classification routine. An unsupervised classifier by region named ISOSEG was employed to classify the segmented images. The analysis of classification results was mainly qualitative and visual except for the 2008 classification which was assessed through an error matrix. According to the error matrix analysis, misclassifications arose more frequently when a set of classes with similar mixture proportions were involved, such as: Capoeira and Campo/Pastagem-2; Campo/Pastagem-1 and Campo/Pastagem- 2; Queimada-1 and Queimada-2, and finally Bare Soil and Campo/Pastagem-1. As a robust measure of concordance for dichotomous data, the kappa statistic reached a value of 0.62 by considering nine land types of classes and it rose to 0.80 when the mapping classes were diminished to six. Theses kappa values represent moderate and strong agreements between the remotely sensed classification and the reference data, respectively. Making use of the classification results from 1987, 1992, 2000 and 2008 and auxiliary data, we tried to design a simple land evolution model to São Félix do Xingu. The deforestation process notably intensified since 2000 has been driven mainly by a continuous increase in cattle breeding, for wich São Félix do Xingu has the second-largest cattle herd of all Brazilian municipalities.
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A aplicação conjunta de método de projeção das alterações no uso e ocupação do solo e de instrumentos de gestão ambiental: o caso de São Carlos (SP) / The joint application of projection methods of the alteration on land use and the environmental policy tools: the São Carlos (SP) caseMarcelo Montaño 08 August 2005 (has links)
A integração do ferramental técnico-científico disponível com os diferentes instrumentos de política e gestão ambiental é essencial para a compatibilização das exigências impostas pelo desenvolvimento com a manutenção ou melhoria da qualidade ambiental e social e, também, para o equacionamento das demandas e dos interesses de cada setor envolvido no processo decisório. Assim, os modelos para a projeção das alterações no uso e ocupação do solo de um determinado território têm sido freqüentemente utilizados. A modelagem propicia a geração e a avaliação das informações para montagem de um panorama das possíveis alterações no uso do solo, considerando que as tendências identificadas para aquele território, num certo instante, sejam mantidas de modo a se desenvolverem de acordo com um determinado cenário projetado. O presente trabalho analisa a possibilidade de aplicação conjunta do método de projeção das alterações no uso e ocupação do solo e instrumentos de política ambiental, levando em conta os aspectos preventivos. Aplicado a uma porção do município de São Carlos (SP), o trabalho apresenta uma projeção para a expansão urbana para os anos de 2012 e 2019, considerando três cenários alternativos de ocupação territorial. Confrontando os resultados obtidos pela modelagem com a capacidade de suporte do meio para a implantação de empreendimentos urbanos - determinada a partir da elaboração de um zoneamento ambiental, verifica-se que, mantidas as tendências atuais, e para os três cenários de ocupação avaliados, a expansão urbana continuará avançando sobre áreas de baixa aptidão para a urbanização, permanecerá exercendo intensa pressão sobre os recursos hídricos e os fragmentos de vegetação nativa, caso não sejam adotadas medidas que modifiquem o atual padrão de ocupação do território. / To compatibilize the demands raised by development with the maintenance or improvement of the social and environmental quality, the integration among technical scientific tools and environmental management instruments is essential to solve the interests of each sector involved at the decision process. On this context are inserted land use and cover change models. The modelling permit the decision-making process to be done evaluating the consequences of possible alterations on land use, which can be identified considering the scenarios projected for the territory under certain circunstances. The presente work analyses the possibility of joint application of this technique and environmental policy tools considering preventive aspects. Allocated to a portion of the São Carlos (SP) municipality, the work projects urban growth for the years 2012 and 2019, considering three alternative scenarios of occupation. Confronting the results obtained by the model with the carrying capacity for the implementation of urban activities - determined from the elaboration of environmental zoning, is showed that, maintained the present tendencies, and for the scenarios evaluated, the urban growth will continue forward and towards the areas with low suitability. In the same way, the pressure over water resources and fragments of native vegetation will remains intense unless measures to modify the standards in occupation can be adopted.
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Estimativa do escorrimento superficial e da produção de sedimentos em áreas de atividades agrossilvopastoris, no Estado de São Paulo, em função da mudança de uso e cobertura do solo / Runoff and sediment yield estimation in agroforestry areas in São Paulo state due to changes in land use and land coverCaroline Alves Galharte 11 November 2011 (has links)
O significativo investimento em desenvolvimento tecnológico associado aos fatores ambientais, como disponibilidade de recursos naturais, clima e solo elevaram o Brasil ao patamar de maior produtor mundial de cana-de-açúcar, matéria-prima do açúcar e do etanol. Atualmente, o país exporta açúcar para mais de 100 países. Em relação ao etanol, esse vem se destacando no cenário mundial devido à viabilidade econômica e à necessidade de se utilizar energia renovável, em substituição aos combustíveis fósseis, com o intuito de mitigar o efeito estufa. Sendo assim, as perspectivas mundiais para a produção e, principalmente, consumo do etanol são favoráveis. Para o Brasil, devido à alta demanda mundial por açúcar e biocombustíveis, o zoneamento agroecológico da cana-de-açúcar, que apresenta uma seleção de terras potenciais para a expansão do seu cultivo visando uma produção sustentável, é uma necessidade imperiosa. Entretanto, os processos de mudança de uso e cobertura do solo são complexos e podem causar impactos, tais como: desertificação, perda da biodiversidade, poluição de ar, degradação dos componentes ambientais água e solo. Esse trabalho acadêmico visou estimar o escorrimento superficial e a produção de sedimentos em área consolidada e em área que encontra-se em expansão do cultivo da cana-de-açúcar para a produção de açúcar e etanol. Para isso, com base no Zoneamento Agroecológico da Cana-de-açúcar (ZAE Cana) que indica as áreas aptas ao cultivo da cana-de-açúcar, foram selecionadas duas áreas de estudo que possuem alta aptidão para a expansão da cana-de-açúcar. São elas: a Microbacia hidrográfica do ribeirão das Guabirobas (MBH-G) localizada no município de São Carlos - SP, região onde a cultura da cana-de-açúcar é consolidada e; a Microbacia hidrográfica córrego da Onça (MBH-O), localizada na região oeste do Estado de São Paulo, nos municípios de Ilha Solteira e Itapura, região onde a cultura da cana-de-açúcar encontra-se em expansão. O modelo de simulação espacial usado no trabalho é o Conversion of Land Use and its Effects at small region extent (CLUE-S), desenvolvido pela Universidade de Wageningen (Holanda). A aplicação satisfatória do CLUE-S permitiu o desenvolvimento de cenários futuros de uso e cobertura do solo com o intuito de simular a expansão da cultura da cana-de-açúcar em paisagens com diferentes características. A posteriori, foi estimada o escorrimento superficial e a produção de sedimentos desses cenários com o auxílio do modelo Soil and Water Assessment Tool (SWAT). O SWAT foi sensível aos cenários, possibilitando a geração de resultados consistentes, qualitativa e quantitativamente para cada um deles, o que permitiu verificar as suas particularidades. Vale ressaltar que a avaliação ex-ante dos impactos ambientais na área de expansão da cultura da cana-de-açúcar em diferentes cenários pode direcionar ações de políticas públicas e de planejamento sócio-econômico-ambiental, dentre outros. / The significant investments in technological development associated to environmental factors, such as the availability of natural resources, for instance, climate and soil, have led Brazil to become the world\'s largest producer of sugarcane, the raw material used in the manufacture of ethanol and sugar. Currently, the country exports sugar to more than 100 countries. Ethanol has become globally eminent due to its economic feasibility and the need of clean and renewable energy rather than of fossil fuels in order to mitigate the greenhouse effect. Therefore, the global perspectives on the production and especially the consumption of ethanol are favorable. Due to the high global demand for sugar and biofuels, the agro-ecological zoning of sugarcane, which features a selection of potential areas for cultivation expansion aiming at sustainable production, is a fundamental necessity for Brazil. However, the changes inland use and land cover are complex processes and can cause impacts such as desertification, biodiversity loss, air pollution, and degradation of environmental components such as water and soil. This research aims to estimate the sediment yield and runoff in areas where the culture of sugarcane is consolidated and in areas of sugarcane expansion for the production of sugar and ethanol. Accordingly, based on the Agro-Ecological Zoning for Sugarcane (ZAE Cana), which indicates suitable areas for sugarcane cultivation, two study areas that have high potential for the expansion of sugarcane were selected, namely the microbacia hidrográfica do ribeirão das Guabirobas/MBH-G (Ribeirão das Guabirobas micro-drainage basin), located in the city of São Carlos - SP, a region where the culture of sugarcane is consolidated, and the microbacia hidrográfica córrego da Onça/MBH-O (córrego da Onça micro-drainage basin), located in the western region of the state of São Paulo, in the cities of Ilha Solteira and Itapura, an area of sugarcane expansion, i.e. a sugarcane expansion region. The spatial simulation model used in this research is the Conversion of Land Use and its Effects at small region extent (CLUE-S), developed by the University of Wageningen, Netherlands. Making use of this methodology, future land use and land cover scenarios were created in order to simulate the expansion of sugarcane cultivation in areas with different characteristics. Subsequently, the sediment yield and superficial runoff in these scenarios were estimated with the help of the SWAT model (Soil and Water Assessment Tool).This model was sensitive to both scenarios allowing the generation of consistent qualitative and quantitative results for each scenario enabling the identification of their particularities. It is noteworthy that the ex-ante evaluation of environmental impacts on areas of sugarcane expansion in different scenarios can guide public policy actions and socio-economic and environmental planning among others.
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Relations spatiales entre les ressources biophysiques et les dynamiques d’occupation du sol du front pionnier en Amazonie orientale / Spatial relationships between biophysical resources and pioneer front dynamics in the Eastern AmazonOsis, Reinis 18 November 2019 (has links)
L’Amazonie est soumise depuis plusieurs décennies à un changement rapide d’occupation du sol du fait de la déforestation, l’installation de systèmes de production agricole, notamment l’élevage bovin et plus récemment le soja. L’un des défis majeurs est de mieux comprendre la dynamique spatiale de ces processus et ses déterminants. Avec la réduction de la déforestation et l’évolution agraire sur les fronts pionniers, les ressources et contraintes naturelles semblent gagner en importance dans les choix opérés par les agriculteurs. L'objectif de la présente recherche est d'évaluer le rôle des facteurs biophysiques dans la dynamique de l’occupation du sol depuis 2000 et d’anticiper sur des futurs possibles dans un territoire amazonien d’ancien front pionnier, aujourd’hui consolidé, la municipalité de Paragominas. Nous avons mis en œuvre un modèle spatialement explicite, afin d’identifier la distribution spatiale des processus de changement en relation avec différents facteurs. Des entretiens réalisés avec des producteurs explicitent les logiques sous-jacentes. Les résultats montrent qu'il y a différentes logiques d'usage des ressources biophysiques, qui varient selon les types de production, la taille des exploitations, la distance aux routes et villages, et la distribution spatiale des ressources biophysiques dans l'exploitation. Elles évoluent au fil du temps, en fonction des productions et des avancées technologiques, et sont organisées dans l'espace. La mise en évidence de ces relations spatiales constitue une avancée significative pour représenter l'évolution de l’ usage des sols et constituer un appui dans la définition de politiques de développement territorial. / The Amazon has been subject to a rapid change in land use due to deforestation for several decades and more recently to the expansion of annual crops like soybeans. One of the major challenges is to understand better the spatial dynamics of these processes and its determinants. With the reduction of deforestation and the consolidation of pioneer fronts, natural resources and constraints seem to be gaining in importance in farmers' choices. The objective of this research was to assess the role of biophysical factors in land use dynamics since 2000 and to anticipate possible futures in a consolidated Amazonian pioneer frontier, the municipality of Paragominas. We implemented a spatially explicit model to identify the spatial distribution of change processes in relation to different factors. Interviews with farmers explain the underlying strategy. The results show different strategies for the use of biophysical resources according to the types of production, the size of the farms, the distance to roads and villages and the spatial distribution of biophysical resources in the farm. The strategies evolve over time, in relation to production and technological advances, and are organized in space. A better understanding of the importance of biophysical resources on the evolution of pioneer fronts through this type of method could provide support for land-use policies.
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Assessing Impacts of Land Use/Cover and Climate Changes on Hydrological Regime in the Headwater Region of the Upper Blue Nile River Basin, EthiopiaWoldesenbet, Tekalegn Ayele 23 June 2017 (has links)
Summary
Fresh water availability and distribution have been declining over time due to population increase, climate change and variability, emerging new demands due to economic growth, and changing consumption patterns. Spatial and temporal changes in environmental changes, such as climate and land use/cover (LULC) dynamics have an enormous impact on water availability. Food and energy security, urbanization and industrial growth, as well as climate change (CC) will pose critical challenges on water resources. Climate variability and change may affect both the supply and demand sides of the balance, and thus add to the challenges. Land-cover changes are vastly prominent in the developing countries that are characterized by agriculture-based economies and rapidly increasing human population. The consequent changes in water availability and increase in per capita water demand will adversely affect the food, water and energy security of those countries. Therefore, evaluating the response of the catchment to environmental changes is crucial in the critical part of the basin for sustainable water resource management and development. In particular, assessing the contribution of individual LULC classes to changes in water balance components is vital for effective water and land resource management, and for mitigation of climate change impacts.
The dynamic water balance of a catchment is analyzed by hydrological models that consider spatio-temporal catchment characteristics. As a result, hydrological models have become indispensable tools for the study of hydrological processes and the impacts of environmental stressors on the hydrologic system. Physically-based distributed hydrological models are able to explicitly account for the spatial variability of hydrological process, catchment characteristics such as climatic parameters, and land use/cover changes. For improved illustration of physical processes in space and time, the distributed hydrological models need serially complete and homogenized rainfall and temperature data. However, observed rainfall and temperature data are neither serially complete nor homogeneous, particularly in developing countries. Using inhomogeneous climatological data inputs to hydrological models affects the output magnitude of climate and land use/cover change impacts and, hence, climate change adaptation.
The Nile River Basin, one of the transboundary river flows through 11 riparian states, serves the livelihoods of millions of people in the basin (nearly 20 per cent of the African population) and covers one-tenth of the land cover of Africa. The basin is characterized by high population growth and high temporal variability in the river flow and rainfall patterns. The Blue Nile river basin, which contributes 62% of the annual main Nile flow, has faced serious land degradation. This has led to increased soil erosion and loss of soil fertility. The most overwhelming challenge that the basin faces is food insecurity caused by subsistence farming and rain-fed agriculture (over 70% of the basin’s population), together with high rainfall variability. Drought and floods are also critical issues in the Blue Nile basin, with the potential for exacerbation by environmental changes. Understanding how LULC and climate changes influence basin hydrology will therefore enable decision makers to introduce policies aimed at reducing the detrimental effects of future environmental changes on water resources. Understanding types and impacts of major environmental stressors in representative and critical regions of the basin is crucial for developing of effective response strategies for sustainable land- and water-resource management in the Eastern Nile Basin in general, and at the Tana and Beles watersheds in particular.
In this study, serially completed and homogenized rainfall and temperature dataset are maintained from 1980 to 2013 to fill-in the gap which characterized previous studies on trend analyses. The new hydroclimatic data revealed that the climate the study region has become wetter and warmer. The proportional contribution of main rainy season rainfall to annual total rainfall has increased. This might result in high runoff and ultimately flooding as well as erosion and sedimentation in the source region of the Blue Nile, and siltation in the downstream reservoirs unless soil and water conservation measures are taking place.
In the Tana sub-basin, it is found that expansion of cultivation land and decline in woody shrub are the major contributors to the rise in surface run-off and to the decline in the groundwater component from 1986 to 2010. Similarly, decline of woodland and expansion of cultivation land are found to be the major contributors to the increase in surface run-off and water yield. They also contributed to the decrease in groundwater and actual evapotranspiration components in the Beles watershed. Increased run-off and reduced baseflow and actual evapotranspiration would have negative impacts on water resources, especially in relation to erosion and sedimentation in the upper Blue Nile River Basin. As a result, expansion of cultivation land and decline in woody shrub/woodland appear to be major environmental stressors affecting local water resources.
GCMs simulated near-future annual total rainfall and average temperature were used to investigate the sensitivity of the catchment to near-future CC. The results showed an increase in streamflow in the annual and the main rainy season, but decrease in the dry period when compared to the baseline period. Catchment response for future LULC scenario showed opposite effect to that of near-future CC. The combined effects of climate change and LULC dynamics can be quite different from the effects resulting from LULC or CC alone. At the outlet of the Tana watershed, streamflow response is amplified under concurrent land cover and climate change scenarios compared to the baseline scenario; but the streamflow has an augmenting response at the outlet of the Beles watershed under future climate change and land use scenarios compared to that of current period. The important inference from these findings is that it could be possible to alleviate intense floods or droughts due to future climate change by planning LULC to achieve particular hydrological effects of land cover in the basin. Continuing expansion of cultivation land and decrease in natural vegetation, coupled with increased rainfall due to climate change, would result in high surface runoff in the main rainy season, which would subsequently increase flooding, erosion and sedimentation in already degraded lands. Sound mitigation measures should therefore be applied to reduce these adverse environmental consequences. On the other hand, the simulated climate and land-use change impacts on the Tana watershed hydrological regime might increase the availability of streamflow to be harnessed by water-storage structures.
In conclusion, the present study has developed an innovative approach to identify the major environmental stressors of critical source region of the Blue Nile River in order to effectively managing the water resources and climate risk. Understanding the catchment responses to environmental changes improves sustainability of the water resources management particularly given that the hydropower and the irrigation schemes are recently established for energy and food security.:TABLE OF CONTENTS
LIST OF ABBREVIATIONS
LIST OF FIGURES
LIST OF TABLES
1. General Introduction
2. The study area
3. Gap Filling and Homogenization of Climatological Datasets in the Headwater Region of the Upper Blue Nile Basin, Ethiopia
Abstract
3.1. Introduction
3.1.1. Data
3.2. Methodology
3.2.1. Quality control and gap filling
3.2.2. Homogenization
3.3. Results and Discussion
3.3.1. Gap filling
3.3.2. Homogeneity
3.3.3. Verification of the homogenization
3.3.4. Impact of homogenization on the rainfall and temperature series
3.4. Conclusions
Acknowledgements
4. Revisiting trend analysis of hydroclimatic data in the Upper Blue Nile basin based on homogenized data
Abstract
4.1 Introduction
4.2 Data and Methodology
4. 2.1 Data
4. 2.2 Linear trend
4. 2.3 Trend magnitude
4.3 Results and Discussions
4.3.1. Linear mean climate trends
4.3.1.1. Rainfall
4.3.1.2. Maximum Temperature (Tmax)
4.3.1.3. Minimum Temperature (Tmin)
4.3.1.4. Mean temperature (Tmean)
4.3.1.5. Diurnal temperature range (DTR)
4.3.1.6. Streamflow
4.3.2. Effect of homogenization on Tmax, Tmin, Tmean and DTR linear trends
4.3.3. Linear extreme climate trends
4.3.1. Temperature
4.3.2. Precipitation
4.4 Conclusions
Acknowledgements
5. Recent Changes in Land Use/Cover in the Headwater Region of the Upper Blue Nile Basin, Ethiopia 85
Abstract
5.1 Introduction
5.2 Materials and Methods
5.2.1 Data used and image pre-processing
5.2.2 Classification accuracy assessment
5.2.3 Extent and rate of change
5.2.4 Detecting the most systematic transitions (dominant signals of change)
5.4 Results and Discussion
5.4.1 Accuracy assessment
5.4.2 Extent and rate of LULC changes
5.4.3 Rate of land use and land cover change
5.4.4 Detection of most systematic transitions
5.5 Conclusions
Acknowledgements
6. Hydrological Responses to Land use/cover Changes in the Tana and Beles Watersheds, the Upper Blue Nile, Ethiopia
Abstract
6.1 Introduction
6.2 Method
6.2.1 Hydrological modeling
6.2.2 Partial least squares regression
6.3 Results and Discussion
6.3.1 Calibration and validation of SWAT
6.3.2 Impacts of LULC changes on hydrology at the basin scale
6.3.3 Contribution of changes in individual LULCs to hydrological components
6.4 Conclusions
Acknowledgements
7. Combined Impact of Climate and Land Use Changes on Hydrology in the Tana and Beles Sub-Basins, Upper Blue Nile, Ethiopia
Abstract
7.1 Introduction
7.2 Methodology
7.2.1 Simulation
7.2.2 Climate change scenarios
7.2.3 LULC change scenarios
7.3 Results and Discussion
7.3.1 Future versus current LULC impact on the basin hydrology
7.3.2 Future versus baseline climate
7.3.3 Impact of combined future climate and LULC changes on hydrology
7.4 Uncertainties and Limitations
7.5 Conclusions
Acknowledgements
8. Overall Conclusions, Recommendations and Future Research Directions
8.1. Overall Conclusions
8.2 Recommendations and Directions for further research
References
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Assessing, monitoring and mapping forest resources in the Blue Nile Region of Sudan using an object-based image analysis approachMahmoud El-Abbas Mustafa, Mustafa 28 January 2015 (has links)
Following the hierarchical nature of forest resource management, the present work focuses on the natural forest cover at various abstraction levels of details, i.e. categorical land use/land cover (LU/LC) level and a continuous empirical estimation of local operational level. As no single sensor presently covers absolutely all the requirements of the entire levels of forest resource assessment, multisource imagery (i.e. RapidEye, TERRA ASTER and LANDSAT TM), in addition to other data and knowledge have been examined. To deal with this structure, an object-based image analysis (OBIA) approach has been assessed in the destabilized Blue Nile region of Sudan as a potential solution to gather the required information for future forest planning and decision making. Moreover, the spatial heterogeneity as well as the rapid changes observed in the region motivates the inspection for more efficient, flexible and accurate methods to update the desired information.
An OBIA approach has been proposed as an alternative analysis framework that can mitigate the deficiency associated with the pixel-based approach. In this sense, the study examines the most popular pixel-based maximum likelihood classifier, as an example of the behavior of spectral classifier toward respective data and regional specifics. In contrast, the OBIA approach analyzes remotely sensed data by incorporating expert analyst knowledge and complimentary ancillary data in a way that somehow simulates human intelligence for image interpretation based on the real-world representation of the features. As the segment is the basic processing unit, various combinations of segmentation criteria were tested to separate similar spectral values into groups of relatively homogeneous pixels. At the categorical subtraction level, rules were developed and optimum features were extracted for each particular class. Two methods were allocated (i.e. Rule Based (RB) and Nearest Neighbour (NN) Classifier) to assign segmented objects to their corresponding classes.
Moreover, the study attempts to answer the questions whether OBIA is inherently more precise at fine spatial resolution than at coarser resolution, and how both pixel-based and OBIA approaches can be compared regarding relative accuracy in function of spatial resolution. As anticipated, this work emphasizes that the OBIA approach is can be proposed as an advanced solution particulary for high resolution imagery, since the accuracies were improved at the different scales applied compare with those of pixel-based approach. Meanwhile, the results achieved by the two approaches are consistently high at a finer RapidEye spatial resolution, and much significantly enhanced with OBIA.
Since the change in LU/LC is rapid and the region is heterogeneous as well as the data vary regarding the date of acquisition and data source, this motivated the implementation of post-classification change detection rather than radiometric transformation methods. Based on thematic LU/LC maps, series of optimized algorithms have been developed to depict the dynamics in LU/LC entities. Therefore, detailed change “from-to” information classes as well as changes statistics were produced. Furthermore, the produced change maps were assessed, which reveals that the accuracy of the change maps is consistently high.
Aggregated to the community-level, social survey of household data provides a comprehensive perspective additionally to EO data. The predetermined hot spots of degraded and successfully recovered areas were investigated. Thus, the study utilized a well-designed questionnaire to address the factors affecting land-cover dynamics and the possible solutions based on local community's perception.
At the operational structural forest stand level, the rationale for incorporating these analyses are to offer a semi-automatic OBIA metrics estimates from which forest attribute is acquired through automated segmentation algorithms at the level of delineated tree crowns or clusters of crowns. Correlation and regression analyses were applied to identify the relations between a wide range of spectral and textural metrics and the field derived forest attributes. The acquired results from the OBIA framework reveal strong relationships and precise estimates. Furthermore, the best fitted models were cross-validated with an independent set of field samples, which revealed a high degree of precision. An important question is how the spatial resolution and spectral range used affect the quality of the developed model this was also discussed based on the different sensors examined.
To conclude, the study reveals that the OBIA has proven capability as an efficient and accurate approach for gaining knowledge about the land features, whether at the operational forest structural attributes or categorical LU/LC level. Moreover, the methodological framework exhibits a potential solution to attain precise facts and figures about the change dynamics and its driving forces. / Da das Waldressourcenmanagement hierarchisch strukturiert ist, beschäftigt sich die vorliegende Arbeit mit der natürlichen Waldbedeckung auf verschiedenen Abstraktionsebenen, das heißt insbesondere mit der Ebene der kategorischen Landnutzung / Landbedeckung (LU/LC) sowie mit der kontinuierlichen empirischen Abschätzung auf lokaler operativer Ebene. Da zurzeit kein Sensor die Anforderungen aller Ebenen der Bewertung von Waldressourcen und von Multisource-Bildmaterialien (d.h. RapidEye, TERRA ASTER und LANDSAT TM) erfüllen kann, wurden zusätzlich andere Formen von Daten und Wissen untersucht und in die Arbeit mit eingebracht. Es wurde eine objekt-basierte Bildanalyse (OBIA) in einer destabilisierten Region des Blauen Nils im Sudan eingesetzt, um nach möglichen Lösungen zu suchen, erforderliche Informationen für die zukünftigen Waldplanung und die Entscheidungsfindung zu sammeln. Außerdem wurden die räumliche Heterogenität, sowie die sehr schnellen Änderungen in der Region untersucht. Dies motiviert nach effizienteren, flexibleren und genaueren Methoden zu suchen, um die gewünschten aktuellen Informationen zu erhalten.
Das Konzept von OBIA wurde als Substitution-Analyse-Rahmen vorgeschlagen, um die Mängel vom früheren pixel-basierten Konzept abzumildern. In diesem Sinne untersucht die Studie die beliebtesten Maximum-Likelihood-Klassifikatoren des pixel-basierten Konzeptes als Beispiel für das Verhalten der spektralen Klassifikatoren in dem jeweiligen Datenbereich und der Region. Im Gegensatz dazu analysiert OBIA Fernerkundungsdaten durch den Einbau von Wissen des Analytikers sowie kostenlose Zusatzdaten in einer Art und Weise, die menschliche Intelligenz für die Bildinterpretation als eine reale Darstellung der Funktion simuliert. Als ein Segment einer Basisverarbeitungseinheit wurden verschiedene Kombinationen von Segmentierungskriterien getestet um ähnliche spektrale Werte in Gruppen von relativ homogenen Pixeln zu trennen. An der kategorische Subtraktionsebene wurden Regeln entwickelt und optimale Eigenschaften für jede besondere Klasse extrahiert. Zwei Verfahren (Rule Based (RB) und Nearest Neighbour (NN) Classifier) wurden zugeteilt um die segmentierten Objekte der entsprechenden Klasse zuzuweisen.
Außerdem versucht die Studie die Fragen zu beantworten, ob OBIA in feiner räumlicher Auflösung grundsätzlich genauer ist als eine gröbere Auflösung, und wie beide, das pixel-basierte und das OBIA Konzept sich in einer relativen Genauigkeit als eine Funktion der räumlichen Auflösung vergleichen lassen. Diese Arbeit zeigt insbesondere, dass das OBIA Konzept eine fortschrittliche Lösung für die Bildanalyse ist, da die Genauigkeiten - an den verschiedenen Skalen angewandt - im Vergleich mit denen der Pixel-basierten Konzept verbessert wurden. Unterdessen waren die berichteten Ergebnisse der feineren räumlichen Auflösung nicht nur für die beiden Ansätze konsequent hoch, sondern durch das OBIA Konzept deutlich verbessert.
Die schnellen Veränderungen und die Heterogenität der Region sowie die unterschiedliche Datenherkunft haben dazu geführt, dass die Umsetzung von Post-Klassifizierungs- Änderungserkennung besser geeignet ist als radiometrische Transformationsmethoden. Basierend auf thematische LU/LC Karten wurden Serien von optimierten Algorithmen entwickelt, um die Dynamik in LU/LC Einheiten darzustellen. Deshalb wurden für Detailänderung "von-bis"-Informationsklassen sowie Veränderungsstatistiken erstellt. Ferner wurden die erzeugten Änderungskarten bewertet, was zeigte, dass die Genauigkeit der Änderungskarten konstant hoch ist.
Aggregiert auf die Gemeinde-Ebene bieten Sozialerhebungen der Haushaltsdaten eine umfassende zusätzliche Sichtweise auf die Fernerkundungsdaten. Die vorher festgelegten degradierten und erfolgreich wiederhergestellten Hot Spots wurden untersucht. Die Studie verwendet einen gut gestalteten Fragebogen um Faktoren die die Dynamik der Änderung der Landbedeckung und mögliche Lösungen, die auf der Wahrnehmung der Gemeinden basieren, anzusprechen.
Auf der Ebene des operativen strukturellen Waldbestandes wird die Begründung für die Einbeziehung dieser Analysen angegeben um semi-automatische OBIA Metriken zu schätzen, die aus dem Wald-Attribut durch automatisierte Segmentierungsalgorithmen in den Baumkronen abgegrenzt oder Cluster von Kronen Ebenen erworben wird. Korrelations- und Regressionsanalysen wurden angewandt, um die Beziehungen zwischen einer Vielzahl von spektralen und strukturellen Metriken und den aus den Untersuchungsgebieten abgeleiteten Waldattributen zu identifizieren. Die Ergebnisse des OBIA Rahmens zeigen starke Beziehungen und präzise Schätzungen. Die besten Modelle waren mit einem unabhängigen Satz von kreuz-validierten Feldproben ausgestattet, welche hohe Genauigkeiten ergaben. Eine wichtige Frage ist, wie die räumliche Auflösung und die verwendete Bandbreite die Qualität der entwickelten Modelle auch auf der Grundlage der verschiedenen untersuchten Sensoren beeinflussen.
Schließlich zeigt die Studie, dass OBIA in der Lage ist, als ein effizienter und genauer Ansatz Kenntnisse über die Landfunktionen zu erlangen, sei es bei operativen Attributen der Waldstruktur oder auch auf der kategorischen LU/LC Ebene. Außerdem zeigt der methodischen Rahmen eine mögliche Lösung um präzise Fakten und Zahlen über die Veränderungsdynamik und ihre Antriebskräfte zu ermitteln.
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