The Temporal and Spatial Dynamic of Soil Erosion and Suspended Sediment Concentration in the Upstream Part of Oum Err Bia River (Middle Atlas/Morocco)

Soil erosion is one of a major environmental issue in many regions of the world, especially in the Mediterranean areas. Due to their climate aggressivity and soil fragility, majority of Mediterranean countries are affected by water erosion. With its localization in the Middle Atlas of Morocco, the upstream part of Oum Err Bia basin is one of the influenced areas by soil erosion. This part of Morocco characterized by steep slopes and weak rocks which make soils vulnerable to water erosion. The purpose of this study is to quantify soil erodibility by applying Revised Universal Soil Loss Equation (RUSLE(, and validate it in the four selected catchments (Tamadout, Faraoun, Almou and Ait Addi catchments). Besides, 32 bottles of samples were collected in the outlet of representative catchments so as to estimate the concentration of sediment. As a result, the obtained annual soil loss average was 145 75 t ha−1 yr−1. However, the concentration of sediment ranged from 0.2 to 234.5 g/l−1. The results confirmed that different factors affect and control the soil loss like intense rainfall events, land uses type, lithology and human activities.