Mudanças no uso e cobertura do solo e seus impactos na erosão hídrica e no potencial natural de erosão na sub-bacia do córrego Santa Maria do Leme

Abstract

This study analyzed water erosion susceptibility and Natural Erosion Potential (NEP) in the Santa Maria do Leme Stream watershed, located in São Carlos, São Paulo, Brazil, considering land use and land cover changes between 2014 and 2024. The research aimed to evaluate soil loss potential through the application of the Revised Universal Soil Loss Equation (RUSLE), combined with geoprocessing techniques, temporal land use analysis, and assessment of Permanent Preservation Areas (PPAs). Environmental and geospatial data were used, including a Digital Elevation Model generated from ALOS/PALSAR satellite data, pedological information from IBGE, climatic data from INMET, and land use and land cover maps from the MapBiomas platform. Based on these data, the RUSLE factors were estimated: rainfall erosivity, soil erodibility, relief, cover and management, and conservation practices. PPAs were also delimited according to the Brazilian Forest Code, considering 30-meter buffers for watercourses and 50-meter buffers for springs. The results showed significant land use changes over the analyzed decade, with the expansion of urbanized areas and mixed-use mosaics to the detriment of pasture areas and sugarcane cultivation. The RUSLE factors indicated that water erosion in the watershed is strongly associated with anthropogenic changes, especially the reduction of vegetation cover and the expansion of more intensive land uses. The generated maps indicated a predominance of soil losses classified as slight to moderate, with punctual occurrences of areas classified as moderate to high susceptibility. In contrast, the NEP results remained relatively stable between 2014 and 2024, with a predominance of the very low class, demonstrating that natural factors alone do not represent high erosive fragility in the watershed. In PPAs, the low NEP and soil loss values reinforced the importance of vegetation in soil protection, reduction of surface runoff, and conservation of water resources. Therefore, the integration of geotechnologies, temporal analysis, and environmental modeling through RUSLE proved to be efficient for identifying areas susceptible to water erosion and supporting environmental planning, territorial management, and PPA conservation actions.