Sahelian West Africa is a region that suffers from high population densities, frequent severe droughts, and enormous pressure on natural resources. Because of these challenges, it is the place where the term "desertification" was originally coined. Recently, however, experts have identified large zones of "greening" where the amount of vegetation exceeds what one would expect based on rainfall alone. This pattern is well documented, but its mechanisms remain poorly understood. This research employs participatory mapping linked with high-resolution satellite imagery to better understand the human role behind regional vegetation trends. Through a case study of three communities in northern Burkina Faso, this paper presents a pilot methodology for explicitly mapping perceived areas of both land degradation and rehabilitation. Combining participatory mapping exercises with standard image classification techniques allows areas of land degradation and rehabilitation to be precisely located and their extents measured for individual communities and their surrounding terroirs. Results of the spatial analysis show that the relative proportion of greening and browning varies among communities. In the case of Sakou, nearly 60 percent of its terroir is degraded. While in another, Kouka, this is 48 percent. This method also elicits perspectives of Burkinabè agro-pastoralists on the local land-use practices driving these twin environmental processes. Altogether, this case study demonstrates the analytical power of integrating ethnography and high-resolution satellite imagery to provide a bottom-up perspective on social-ecological dynamics.
Keywords: Land degradation; Sahel greening; participatory mapping; remote sensing.