Assessment of soil erosion in the Cesar watershed, an initial step toward the restoration of the Cesar River

The Magdalena River stands out as the largest contributors of sediment in South America. Although the Cesar River is one the main tributary of the Magdalena River, very few studies, if any, have focused on estimating soil erosion rates in the Cesar watershed. This contribution addresses this gap by presenting soil erosion rates calculated specifically for the Cesar watershed. It is based on the RUSLE-GGS (RUSLE-GIS-GLUE-SDR) erosion model at the watershed scale. The estimates cover a period from 1991 up to 2020, with a spatial resolution of 2.5 km. Different scenarios were modeled to assess and predict the variations in sediment yield and to fit the model to the sediment concentration data observed in local sediment gauging stations. By using the Getis-Ord statistical analysis, hotspots where soil erosion is most pronounced were identified. To the best of our knowledge, this contribution represents the first assessment of soil erosion in the Cesar watershed. In addition to providing a basis for future research, the results are expected to contribute to the formulation of appropriate scenarios to address the restoration of the Cesar River. Finally, the study triggers a discussion on the sustainable management of the basin to explore solutions aimed at preserving the integrity of this vital water resource.