干旱区生态环境知识资源中心

In northern Algeria, the physical degradation of land by water erosion is one of the most serious forms of degradation. As is well known, vegetation plays an important role against water erosion. In the mentioned area the potential vegetation called maquis is currently characterized by an advanced stated of degradation, often ranging between sparse cover and bare soil. In the Oued Fergoug watershed belonging to the Beni Chougrane Mountains (NW of Algeria), a trial was carried out with a mini rainfall simulator designed by ORSTOM to evaluate the runoff rate and the sediment load at experimental plot scale and in a situation of bare soil. The experimental layout took into account two different surface slopes, three different rainfall intensities, and three levels of initial soil water content. The highest runoff values observed exceeded 0.50 mm min(-1) and the maximum sediment load yield was 94.2 g L-1 per square meter. Summarizing, the intensity of rain is the main factor for runoff generation, independently of the slope and the initial soil water content values. Since vegetation cover is a crucial component in maintaining stable slopes and limiting soil losses, the most effective practice to protect bare soil against erosion is to provide a protective ground plant cover in this area.