Etude d'érosion et du ruissellement sur bassins versants expérimentaux dans les monts de Beni-Chougrane (Ouest d'Algérie)

The Beni-Chougrane mountains (West of Algeria) are submitted to an intense activity of erosion. This phenomenon has provoked the agricultural ground degradation and the siltation of Fergoug reservoir. To study and understand the phenomenon in this region, the National Institute of Forest Researches of Mascara has established an experimental station (cf. Wischmeir 1968). Thus experiences have been led on two characteristic local soil types: a Chalky brown ground on 20 % on sandstone slopes and brown vertisol on 45 % clayey - marl slopes. Taking the totality of data (4 campaigns measures) we have shown that the rain, the runoff and the state of humidity of the ground can not explain correctly to them alone and separately the variance of the erosion phenomenon. On the other hand, the grouped in data by season gives best relationships between the specific degradation and explanatory factors, as well as relationships between the depth of runoff, the rain and the state of humidity of the ground. In hot seasons energy provoked by the rain is relatively important than the energy provoked by runoff. While in cold seasons energy of the runoff is more important than the energy provoked by the rain.