ESTIMATION OF SOIL LOSSES BY THE IMPROVED TILLAGE HOMOGENIZATION MODEL AND RUSLE MODEL

Abstract. Soil erosion by water is a major environmental problem in the Mediterranean areas. It results in land degradation and soil losses, decreases soil structural stability, and increases soil erodibility. Hence, the need for reliable scientific methods for obtaining soil erosion data becomes crucial. The study aims to estimate soil loss in the Moroccan watershed using two soil erosion estimation models and to discuss the differences between those models. The first model used in this study is the improved tillage homogenization model (T-H) which permits to predict the magnetic susceptibility values after erosion, the second one is the empirical model based on the Revised Universal Soil Loss Equation RUSLE. The results showed that: i) higher soil losses using tillage homogenization (T-H) model have occurred in the upper and lower slopes in the cultivated transect, and in the middleslopes and lower slopes in the forested transect; ii) the average of annual soil loss obtained by RUSLE model is about 20.21 t/ha/yr; iii) T-H model allows us to estimate the total cumulative soil erosion during the past and, while RUSLE model is designed for predicting annual soil loss resulting from sheet erosion under given conditions.