The aim of this paper is to evaluate the impact of forest cover dynamics on the erosion at Kharouba watershed in the Moroccan Central Plateau. Our methodology is based on the diachronic analysis of the land cover between 1986 and 2016, using treatments of aerial photographs from 1986 and a Google Earth satellite imagery at a high resolution from 2016. The land cover maps obtained were used to establish erosion status maps between 1986 and 2016, based on methodology PAP/RAC. Our study highlights the regressive evolution of vegetation cover. This decline has stressed the increased water erosion risk in Kharouba watershed causing the spread of the areas that are vulnerable to water erosion from 36 % in 1986 up to 41 % in 2016.