Study of the vulnerability of the Bouregreg basin to the risk of water erosion

Abstract

Water erosion is a major agronomic, economic and environmental concern in semi-arid Mediterranean environments. The choice of method to estimate it depends on the data available and the conditions of the study area. Located in north-west Morocco, with a surface area of 9971.54 km2, the Bouregreg basin suffers from the phenomenon of water erosion. The aim of this study is to investigate and quantify water erosion in this basin by applying the RUSLE model integrated with remote sensing and a Geographic Information System. An exhaustive study of the study area was carried out in order to characterize the main factors involved in the evolution of water erosion in the Bouregreg basin. The results of this study demonstrated that the simultaneous presence of watercourses running through easily erodible areas, as well as steep slopes with no plant cover, aggravate this phenomenon and exert a control over its evolution. The results obtained by the RUSLE model indicate an estimated average soil loss of 4.9 t/ha/year, with a minimum of 0 t/ha/year and a maximum of 89.4 t/ha/year. Furthermore, comparison of the soil loss estimates obtained in this study with those from previous work reveals relatively minor differences.