Conversão de áreas e impactos antrópicos na bacia hidrográfica do Rio Teles Pires

Abstract

The south of the Amazon Region, in Brazil, where the Teles Pires river basin is located, presents itself as a region of great natural diversity and full economic development, which has been undergoing intense changes in terms of land use and occupation, pointing out for the need to monitor such changes, in view of the negative impacts that can be generated on the environment. To contribute to the generation and updating of information that broadens the knowledge about the territorial dynamics of the region and provides subsidies for the management of water resources, this research aimed to evaluate the changes in land occupation and use in the hydrographic basin of the Teles Pires River over the past 34 years and to quantify the Permanent Preservation Areas (APPs) of the water bodies in this basin according to the current legislation, finding out if there is a conflict in relation to the use and occupation of these areas to then verify the occurrence of degradation. Using images from the TM and OLI sensors, Landsat 5 and 8 satellites, and a classification technique supervised by maximum likelihood, land use and occupation maps for the basin, corresponding to the period between 1986 and 2020, were generated and the main land conversion conversions were identified. land use that occurred. For the delimitation of APPs, the Modified Normalized Water Difference Index (MNDWI) was used to delineate water bodies, and these were delimited according to Law 12.651 / 2012. In order to identify the existence of conflicts regarding land use within the PPAs, their delimitation was crossed with the land use and occupation map for the year 2020. The results indicated that the main changes that occurred in the hydrographic basin of the Teles Pires River resulted from the conversion of areas of the Brazilian cerrado and forest classes to agriculture and pasture, and from these agricultures recorded greater percentage growth and the Brazilian cerrado the greatest reduction. The intensity of conversion of areas registered at different times can be related to the economic and political conditions experienced by the country. The APP delimited for the basin was equivalent to 3.96% of its total area and presented a low state of degradation, with the pasture representing the main type of conflicting use. The spatialization of conflicts within the basin showed contrasts between the different regions, indicating that the most critical areas in relation to the conservation of APPs are located in the central-eastern portion of the basin.