Erosion and Sedimentation Processes in a Semi-Arid Basin of the Brazilian Savanna under Different Land Use, Climate Change, and Conservation Scenarios

Abstract

Estimating the on-site and off-site impacts of soil erosion as a function of land use and climate conditions in semi-arid basins is key for soil and water conservation strategies. However, a research gap exists in the theme, requiring further investigation using local hydrological data. To accomplish it, the SDR-InVEST model was applied to the Pardo-FB basin (Brazil) using different land use, soil conservation, and climate conditions. The mean annual soil loss and the mean sediment yield in the basin varied between 7 and 36 Mg ha−1 yr−1 and 1.2 and 52.2 Gg yr−1, respectively. The basin areas where on-site and off-site erosion tolerances were exceeded ranged from 20% to 50% and from 0% to 1%, respectively, depending on the scenario. The results indicate that anthropic areas and high erosivities increase soil detachment and decrease sediment retention, generating higher erosion and sedimentation rates in the basin. The restoration of native vegetation and soil conservation practices reduced the erosion impacts, but their effectiveness was reduced in the wet climate scenario. The results contribute to the establishment of soil conservation strategies in the Pardo basin, as well as in similar basins around the world.