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Análise global de tendências em contagens de fogos noturnos ativos (1996 - 2012)

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Resumo:This thesis aimed to perform a trend analysis of the global distribution of vegetation fires for the period from June 1996 to March 2012. We used the product from the World Fires Atlas (WFA) from the European Space Agency (ESA), obtained with the Along Track Scanning Radiometer (ATSR) sensor onboard the Second European Remote Sensing Satallite (ERS – 2), under which a filtering process was applied, following the same method of Mota et al. (2006). We conducted a comparative analysis between the initial data and the clean data and there was a percentage of false alarmes and fires that were not vegetation fires of 28%. The errors obtained were due primarily to hot surfaces and gas flares. With the data obtained, we conducted a trend analysis by performing the Mann-Kendall test in the program IDRISI Selva. The mapping created by the test, was studied to identity the presence of positive or negative trends. After a close visual study of the mapping and after the analysis of the temporal profiles of places of interest, we concluded that there is no relevant trend present globally, both positive or negative.
Autores principais:Pinto, Diogo Miguel da Silva de Sousa
Assunto:vegetation fires ATSR trend analysis Mann-Kendall IDRISI
Ano:2014
País:Portugal
Tipo de documento:dissertação de mestrado
Tipo de acesso:acesso aberto
Instituição associada:Universidade de Lisboa
Idioma:português
Origem:Repositório da Universidade de Lisboa
Descrição
Resumo:This thesis aimed to perform a trend analysis of the global distribution of vegetation fires for the period from June 1996 to March 2012. We used the product from the World Fires Atlas (WFA) from the European Space Agency (ESA), obtained with the Along Track Scanning Radiometer (ATSR) sensor onboard the Second European Remote Sensing Satallite (ERS – 2), under which a filtering process was applied, following the same method of Mota et al. (2006). We conducted a comparative analysis between the initial data and the clean data and there was a percentage of false alarmes and fires that were not vegetation fires of 28%. The errors obtained were due primarily to hot surfaces and gas flares. With the data obtained, we conducted a trend analysis by performing the Mann-Kendall test in the program IDRISI Selva. The mapping created by the test, was studied to identity the presence of positive or negative trends. After a close visual study of the mapping and after the analysis of the temporal profiles of places of interest, we concluded that there is no relevant trend present globally, both positive or negative.