ABSTRACT
The Sahelian area is primarily identified by a set of physical and natural features. The principal criteria for a delineation and description of its characteristics are drawn from the observation of climate, soils and vegetation. The combination of these different variables creates a wide heterogeneity within local sites. The unequal impact of human activity brings with it an additional element of diversification, creating transformation processes which, in their most extreme manifestations, can lead to the degradation of environments which is then difficult to reverse.
