This Dossier begins with a presentation of a few physics concepts that are essential for understanding remote sensing, and a description of the main parameters that can be monitored by satellite. Several recent examples regarding the various possible uses of satellite images for the purpose of combating desertification are then proposed. The Dossier concludes by offering a guide on practical ways to advance in remote sensing via freeware and satellite images provided free of charge by French, European, and American space agencies.

A hard copy version is available from CSFD upon request

Arid and semiarid West African regions are characterized by heavy environmental constraints that have shaped natural ecosystems and human activities:

• low, infrequent, irregular, unpredictable rainfall concentrated within a period of a few months
• soils mainly with low organic matter and nutrient content.

Fauna, flora and natural ecosystems—savannas and dry forests—are thus adapted to these more or less prolonged arid conditions. Crop and livestock farming activities, which are highly prevalent in these regions, have also adapted to these constraints over time, primarily to ensure food self-sufficiency, especially through tree-crop-livestock integration. This combination may be noted in farms and villages inhabited by livestock and crop farmers and where both trees and crops grow side-by-side, but also on larger (...)