Soil erosion assessment in Northwestern Morocco

Abstract

In this study, the climate and land use change impact on soil water erosion in Loukkos watershed (northwestern Morocco) was assessed. This watershed is known by its intense agricultural activity and characterized by a Mediterranean climate. In order to quantify soil erosion, RUSLE model was used, combined with remote sensing and GIS technology under current and future climate scenarios predicted by the model CNRM-ALADIN63 for 2025–2055. The precipitation for the future climate period (2025–2055) was downscaled using CMhyd's statistical downscaling model (quantile-quantile).The results showed that the annual soil erosion rate averaged about 3.0 t, with a standard deviation of 6.2. In contrast, soil loss of less than 10 t ha−1 yr−1 occurred in 92% of the watershed. While overall erosion estimates show a medium erosion risk, attention and use of soil conservation practices is suggested for 7.1% of area has experienced soil erosion greater than 10 t ha−1 yr−1. Furthermore, the results revealed that average annual soil loss could increase by 3.9% and 8.4% respectively for medium and high Representative Concentration Pathways (RCP 4.5 and RCP 8.5) compared to the baseline period (1981–2017). Soil erosion assessment and land use change were determined to help implement future conservation measures for decision makers to develop appropriate strategies for long-term planning of water and soil resources, risk mapping and agriculture under various climate change scenarios.