Evolução anual de desmatamentos na floresta nacional do tapajós

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Evolução anual de desmatamentos na Floresta Nacional do Tapajós de 1997 a 2005 Daniel Cohenca 1 Analista Ambiental - Floresta Nacional do Tapajós Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis – IBAMA Av. Tapajos, 2267 - 68100-040 - Santarém - PA - Brasil [e-mail]
Abstract: The Tapajós National Forest (Floresta Nacional do Tapajós) is a federal protected area of sustainable use, located at the BR163 road influence area, in the west of Pará state, Amazon region - Brazil. It has 544,000 hectares (ha) and a resident population estimated in 6000 people. In the Tapajós National Forest the inhabitants are authorized by IBAMA to make small deforestations until 3ha per year for slash-and-burn agriculture, but the agency detects also some occurrences of bigger unhallowed deforestations that clash with the existing rules of land usage in the population zones of the area. In this comparative study of the deforestations occurred annually in the Tapajós National Forest the Maximum Likelihood classification algorithm was applied on LandSat and CBERS satellite images from 1997 to 2006. The resultant vectors were then subtracted and the annual deforestation taxes calculated. The results were analyzed in terms of annual evolution, population area in which deforestations are located and in terms of size of the deforested polygons. Always differentiating the deforestation occurred in area of primary and secondary forest. The results suggest an ascending annual curve of the deforestation taxes in the protected area and that 33% of deforestation occurred in the study period was in primary forest (1786ha or an average of 198ha/year). The population areas that contributed more for the deforestation were the ‘Ribeirinha’ and ‘Planalto’ areas, however this last one with 45.6% occurrences on primary forest against only 11% of the riverside population (Ribeirinha). Some actions are suggested to strategically reduce the