Estimating sediment yield by a distributed sediment delivery model at the Carapelle experimental basin (Southern Italy)

Abstract

The Carapelle basin (Apulia, Southern Italy) is affected by significant soil erosion processes, exacerbated by its Mediterranean climate and agricultural practices. In this study, the SEdiment Delivery Distributed (SEDD) model is applied to investigate sediment transport and erosion processes over a five-year period. Key factors, including slope steepness and length, land cover, soil erodibility, and climatic conditions, were integrated into the SEDD model to identify areas vulnerable to gross soil erosion. Data collected from rainfall gauges distributed across the basin, together with streamflow and sediment concentration measurements carried out at the basin outlet, were used to calibrate the SEDD model at both annual and mean annual temporal scales. Results identified that 51% of the basin area is characterized by soil loss values exceeding tolerance threshold, while only 7.5% of the basin area is characterized by sediment yield values greater than 10 Mg ha⁻1. In these areas Best Management Practices (BMPs), such as cover crops, or soil conservation strategies could be implemented to mitigate in-site and off-site effects of soil erosion processes, respectively. Future research will be oriented to simulate soil erosion and sediment yield under alternative scenarios characterized by the application of BMPs and to assess their economic effectiveness.