Science et changements planétaires / Sécheresse


Ecoclimatic approach of the pastoral potential of Sahelian regions Volume 13, issue 2, Juin 2002


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Cirad-EMVT/CNRS, Campus de Baillarguet, TA 30/F, 34398 Montpellier Cedex 5, France.
  • Page(s) : 73-9
  • Published in: 2002

A critical analysis of the vast literature on the relations between the climate and the productivity of Sahelian formations made it possible to infer that the production of herbaceous and of seeds, as well as the production of leaves by woody plants, are proportional to yearly rainfall as soon as it exceeds 75 mm, but that there is a mutual compensation between the two. Models are proposed. Additionally, it is underlined, using Budyko's formulas, that the evaporating capacity of the air is, at a first approximation, proportional to the average annual temperature: it is so high that the ponds created by the rains of the wet season are drained before the end of the dry season. It therefore means that the cattle's drinking water must in part be provided by some underground water source or through an access to a permanent rive source. These results allow the surface necessary per capita of cattle to be assessed based on climate conditions. At application level, the important variations related to station condition should be accounted for.