Estimation of erosion and sediment yield in the N’sele catchment, Democratic Republic of Congo

Sediment transport in rivers is associated with huge environmental and engineering issues. N’sele River is known to carry heavy sediment load into the Malebo Pool due to the extensive erosion in the basin. The empirical approach known as EPM incorporated into a GIS was applied to evaluate the erosion intensity as well as the estimation of sediment yield. The study was conducted in the N’sele catchment, the ungauged basin of approximatively 4623 Km2. The EPM is a parametric distributed model that uses climate (rainfall and temperature), Lithology, land use, slope and observed erosion processes data. These data layers were generated from the DEM, Landsat 8, Satellite products (CHIRPS and GLDAS), SOTERCAF database and GLASOD map. The combination of these layers as raster-based GIS have generated the erosion-severity and sediment yield maps as important tools for management practices in erosion protection. The output of the average specific sediment yield of 92 ± 52 ton/km2/year was compared to the existing information of the region on erosion. The comparison performed well and the results obtained show that the downstream of the basin and a part of the upper catchment is moderately eroded. In order to suggest an efficient sediment management practice, the basin was divided into 21 sub-catchments and the prioritization of sub-catchment based on their average specific sediment yield was done. To curtail soil erosion, mitigation and preventive measures were proposed.