Agronomy and climatology of a 100 000 km² watershed in West Africa.
Résumé
Sahelian regions are considered as particularly vulnerable to climatic variability and change for two reasons: the dominant role of rainfed agriculture in their economies and their weakness of water resources management. The physiological response of an individual plant to the climatic variations of parameters is well documented, but extrapolation to regional food production still remains very dubious. On the Bani, a tributary of the Niger River in Mali, climatic variables representative of the agroclimatic constraints of the cultures (dynamics of the rainy season and occurrence of extreme events) were evaluated from observed past data and simulated future data (regional climatic model WRF). Simple and multiple correlations were established between past data and agricultural yields, but the relations are hardly significant. In these regions in Africa, the climate factor is certainly a necessary condition to explain the agricultural outputs, but not sufficient alone.