Multidecadal analysis of erosion susceptibility in a watershed heavily impacted by deforestation in southeastern Amazonia

Le résumé fourni par la source

Over the last several decades, extensive changes in land use and land cover (LULC) have caused substantial environmental impacts in the watersheds of southeastern Amazonia, such as the Verde River Watershed (VRW). The effects of anthropogenic activities on soil cover loss rates in the VRW were evaluated to estimate soil loss over time by applying the revised Universal Soil Loss Equation (RUSLE) in a geographic information system (GIS) environment via rainfall erosivity ( R ), soil erodibility ( K ), topography ( LS ), and LULC ( CP ) data. The VRW experiences strong seasonality, with the most significant R concentrated from January to April, which coincides with a relatively high rainfall index reaching approximately 42% of the annual total. Most of the VRW has gently undulating to flat relief (88.9%) and low LS values (0.02–0.025), but its upper course has a sandy soil texture with high K values (0.02–0.073). Pastureland has replaced forested areas during the past 40 years, dramatically changing the landscape with more significant changes in LULC rates in the upper VRW. Estimates of annual and average soil losses and areas at high and very high risk of erosion increased by more than 200% from 1984 to 2021. In conclusion, deforestation is the main factor influencing erosion patterns and volume in the VRW and has accelerated soil degradation, increasing the risks to human health and the maintenance of tropical rainforests. Additionally, simply stopping deforestation is insufficient to prevent the expansion of areas with high and very high erosion risk. It is crucial to implement reforestation projects to recover forested areas.

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