Land use evolution and effects on the degradation of Permanent Preserved Areas of Piedade River Watershed (1985-2011), MG, Brazil
Amara Borges Amaral, Silvio Carlos Rodrigues

The current state of environmental degradation has mobilized society and led researchers and public administration to propose mechanisms for the protection of natural resources. Environmental studies have focused on increasing the diagnosis of watersheds, identifying the strengths and weaknesses of the study area, later to establish the planning and management guidelines to be followed. In Minas Gerais, after publication of the State Policy on Water Resources – Law n°. 13.199/1999, the Minas Gerais Institute of Water Management has proposed the division of the state in units of Planning and Management of Water Resources having the parameter by of geographical division of watersheds. Not only for the assessment of water resources, the watershed has also been adopted as a planning unit for different environmental studies such as physical and biotic diagnosis, landscape analysis, use and occupancy of soil surveys, landscape ecology surveys, among several others. In this perspective, because of its relevance to the mesoregion of Triângulo Mineiro, it was adopted as the unit of study the Piedade River Watershed - PRW, an area of approximately 1746,89 Km2. The main objective was to assess the modification of the landscape arising from human occupation in the period from 1985 through 2011, verifying its reflection on environmental conditions in the basin under discussion, especially in the fragmentation of native vegetation along it and the Permanent Preservation Areas (PPA). In order to achieve the objective of this research, we used the available studies on this subject, consolidating the theoretical framework and defining the work methodology that basically consisted of technical visits to the Piedade river watershed; mapping of land use and land cover for the years 1985, 1995, 2005 and 2011, qualitative and quantitative definition of Permanent Preservation Areas according to Federal Law. 4.771/1965 (Forestry Code), delineation of remnants of native vegetation. The study of PRW, among other figures, showed development of the use and occupancy between 1985 and 2011. From this it was possible to notice that in 1985 the rate of native cover was 28.87% of the basin, however, between the years 1985 and 1995 there was a reduction of native vegetation to 35%, reaching only 17.73 % of the basin in 2011, this percentage being computed areas with native vegetation in areas of permanent preservation. Analyzing the data obtained in this work, in a general sense, it is concluded that the sheer existence of an environmental law protecting natural resources, has not been able to minimize the negative effects of human occupancy on the protected areas. It is evident the urgent need for diagnoses and integrated studies that can be translated into tools of land management on the basis of environmental planning.

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