Quantification of Soil Sensitivity to Water Erosion by the RUSLE Model in the Oued Amter Watershed, Northwestern Morocco

Abstract

The present study aims to estimate the soil losses in the watershed of Oued Amter extends the length of the internal Rifain domain, located in the region of Tangier-Tetouan-Al Houceima, Chefchaouen province in north-western Morocco. The spatialization of the empirical model was based on the integration of five factors in the Geographic Information System, namely, rainfall erosivity, soil erodibility, vegetation cover, topography and anti-erosion practices, and whose superposition allowed the elaboration of the quantitative map of soil losses at the watershed scale. The Oued Amter watershed covers an area of 300 km2 ; it is elongated with an altitude ranging from 0 m to 2100 m from north to south and a slope that varies from 0 to 58.58%. The rainfall study of the climatic stations located near the watershed has shown the irregularity of rainfall in time and space. The erosivity factor R presented values ranging from 1637.09 to 1937.61, with an average of 1787.35 Mj.mm/ha. h. an (Millijoule. Millimeters/hectare. Hour. Year). The erodibility factor K presents values from 0.139 to 0.140 and it showed that the soils little evolved and the Vertisols are the most vulnerable to erosion.