Dinâmica da paisagem da Bacia Hidrográfica do Rio Apeú, Nordeste do Pará, Brasil.

Abstract

In the historical analysis of the development of the Amazon Region, focusing the relation between man and natural resources, the Northeast of Pará shows itself as one of the oldest agricultural frontiers of the State and, surely, the most affected by the environmental problems. For an understanding of the evolutionary history of the Landscape, the Hydrographical Basin becomes one natural planning unit of the natural resources which makes possible to identify the transformations through which the environment has undergone and its main motivations. Therefore, this paper aimed to analyze the dynamics of the natural coverage and of the use of soil in the Hydrographical Basin of the Apeú River in 7 years. For this purpose, there were used Landsat5/TM images referring to 2001, 2004 and 2008, which were classified by the maximum verisimilitude supervised classification algorithm, using the ENVI program. Through the analysis of the thematic maps generated for the three periods that were analysed, it was possible to notice the dynamics of the natural coverage and of the use of soil. The results have shown that the Landscape of the Basin is strongly marked by livestock and the pastures are the most predominant use of the soil. The “Secondary System” class, although suffers progressive reduction along the seven years that were analysed, still is the predominant cover in the landscape, which is attributed to the sustainability of the local agricultural production system as a component of fallow. In the landscape’s dynamism, the tropical rain forest is the class which has greatest stability in the natural coverage, being mainly concentrated on the banks of watercourses, being Permanent Preservation Areas. However, it is still worrying the occupation of the land in areas near the water bodies near the area of the Hydrographical Basin of the Apeu river, since 22% of the conceptual PPAs are not protected by the law.