DESERTIFICATION, DROUGHT, AND SURFACE VEGETATION - AN EXAMPLE FROM THE WEST-AFRICAN SAHEL

Many assumptions have been made about the nature and character of dese rtification in West Africa. This paper examines the history of this is sue, reviews the current state of our knowledge concerning the meteoro logical aspects of desertification, and presents the results of a sele ct group of analyses related to this question. The common notion of de sertification is of an advancing ''desert,'' a generally irreversible anthropogenic process. This process has been Linked to increased surfa ce albedo, increased dust generation, and reduced productivity of the land. This study demonstrates that there has been no progressive chang e of either the Saharan boundary or vegetation cover in the Sahel duri ng the last 16 years, nor has there been a systematic reduction of ''p roductivity'' as assessed by the water-use efficiency of the vegetatio n cover. While it also showed little change in surface albedo during t he years analyzed, this study suggests that a change in albedo of up t o 0.10% since the 1950s is conceivable.