L'homme et l'eau dans le bassin du lac Tchad = Man and water in the lake Chad basin

Abstract

That the notorious Sahelian drought (1968-1973) of Sahelo-Sudan Sub-Sahara was not unique has been established as a chronological sequence of past droughts in the Lake Chad basin. Historical drought chronology is traceable to written evidence. Pre-historical evidence of dune landscapes in the Nigerian Lake Chad basin may be located on the ground or in satellite imagery. Nevertheless, the 1980s drought continuum has the characteristic of being unique in the context of its severity and longevity. Some possible forcing agencies are considered as being meterological, while anthropogenetically-induced drought-desiccation is also of concern. Recently it has been indicated that a linkage between sea-surface temperatures and sahelian droughts seems to be of significance. (Résumé d'auteur