Since some decades, the Ivorian Comoe river Basin faced environmental and climatic changes. As one of rainfed agriculture leading forces, climate conditions display (here) a major role in agriculture transformations. The simulation of water need requirements, coupled with farming systems, shows that actual global changes mainly benefit to annual crops such as corn (Zea mays), and allows the upgrading of the trees crop as cashew (Anacardium occidentale), rubber tree (Hevea brasiliensis), etc. However, the precariousness of the production systems, whose practices have not deeply changed, has to be linked with the combined effects of land saturation, agricultural policies and need of cash faced by farming communities. Therefore, the diversification and reconversion toward rubber plantation, are to be considered as farmers' strategies aiming at finding alternatives for old speculations such as coffee. (Texte intégral)