Deforestation patterns and stages of the Southern Amazon agricultural frontier

From 1980 to 2020, the Paciá River Drainage Basin (BHRP – Bacia Hidrográfica do Rio Paciá), located in the Southern Amazon agricultural frontier, underwent an accelerated process of change in human land use and occupation. This study aimed to identify and analyze deforestation patterns, relating them to landscape metrics and the stages of expansion of the agricultural frontier. The methodology was based on the following phases: 1) organizational structure of GIS (Geographic Information System) modeling; 2) mapping and classification of deforestation patterns; 3) mapping of the expansion stages of the agricultural frontier. Diffuse and geometric patterns represented 72.5% of the polygons analyzed, corresponding to 15.64% of deforestation. However, linear and consolidated patterns, which referred to 12.5% of the polygons, represented 65.5% of the deforested areas in the BHRP. The spatial arrangements of deforestation polygons are associated with two evolutionary stages of the Amazon agricultural frontier: permanent/consolidated, which is located along the Transamazon highway, and pioneer/diffuse, located along the banks of rural roads and the main course of the Paciá River.