Mapping and temporary analysis of the landscape in the Tucuruí-pa reservoir surroundings

Abstract

The great interest of generating “clean” energy in the countries of the region for energy supply and continuous economic growth, motivates the planning and construction of large hydroelectric projects, with a significant presence in the Amazon basin. Nevertheless, due to the extent of the reservoirs generated by these projects, the dynamics of natural ecosystems may be altered. To better understand the spatial pattern of land cover changes fostered by large hydroelectric reservoirs, this study applied the linear mixture model in segmented Landsat-TM and ETM+ images, and landscape metrics for the mapping of land cover classes in municipalities directly affected by the Tucuruí-PA reservoir, and the quantitative characterization of the classes present in the region, between the periods of completion of the 1st phase and the beginning of the 2nd phase of construction of the Tucuruí hydroelectric plant. The results of the spatial analysis indicated that there were modifications in the spatial pattern of the forest cover in the surroundings of the Tucuruí reservoir, with differentiated behaviors in the scale of municipalities, in which the high level of fragmentation is associated to the connectivity of the highways between the urban spots present in them, facilitating the access and conversion of forest areas into pasture.