Áreas de preservação permanente da bacia do Rio Lonqueador: análise do conflito de uso do solo e do potencial erosivo

Abstract

The irregular occupation of Permanent Preservation Areas (APPs) has significantly contributed to the environmental degradation of river basins, especially in regions undergoing intense urbanization. However, there is a scarcity of studies that articulate the analysis of the legal compliance of these areas with the quantification of the physical impacts resulting from changes in land use, such as the formation of erosive processes. In this context, this study aimed to analyze the APPs of the Lonqueador River basin, with an emphasis on identifying conflicts related to land use and occupation and on evaluating the erosive potential. The research is characterized as applied, with a quantitative approach, with a descriptive and explanatory focus, based on inductive procedures and the use of geotechnologies. The methodology involved the acquisition, preparation, and analysis of geospatial data, including satellite images, with the application of digital image processing and geoprocessing techniques in a GIS environment, using QGIS software. The erosive potential estimate was based on the Universal Soil Loss Equation (USLE), applied comparatively to real and ideal land use and land cover scenarios. The results indicate that, in the Lonqueador River basin, the identified riparian buffer zones (APPs) are predominantly concentrated along watercourses and springs, totaling approximately 252 hectares. The temporal analysis of land use and occupation dynamics within the APPs, between 2016 and 2025, revealed a progressive reduction in native vegetation and the expansion of anthropogenic uses, especially urbanized areas, pastures, forestry, and temporary crops, highlighting conflicts in legally protected areas. The modeling of the erosion potential in these areas demonstrated that, although the very low soil loss class predominates in the real-world scenario (≤ 2,5 t/ha/year), localized increases occur in higher classes (5,0 – 7,5; 7,5 – 10,0; and> 10,0 t/ha/year), associated with the suppression or fragmentation of vegetation cover. Regarding the ideal preservation scenario, high stability was observed throughout the analyzed period, with almost the entire area (99%) falling into the lowest soil loss class (≤ 0,025 t/ha/year), indicating that the identified differences result from changes in land cover and land use, and not from natural basin conditions. Thus, it is evident that changes in land use and occupation in the riparian zones of the Lonqueador River throughout the analyzed period compromise the effectiveness of their protective function, with a punctual increase in erosive susceptibility and a reduction in the protection of water resources and soil stability, in addition to constituting a blatant non-compliance with the precepts of the Brazilian Forest Code, evidenced by the occurrence of 145,27 hectares (57,6%) of conflicting uses on legally protected areas, which correspond to 14,4% of the total area of the basin.