Influence de la dynamique de l’occupation des terres sur les ressources en eau au Benin (Afrique de L’Ouest)

Abstract

This study is a contribution to a better understanding of the dynamics of land occupations in West Africa and its impacts on water resources. Its main objective is to present advances on the subject in order to better define the challenges to be met in the next studies. To achieve this, the maps of the “Land Use Dynamics in West Africa” project was used. Additionally, recent scientific documents/reports and articles have been used in order to present a summary view of the information collected. From the analysis of these results, it emerges that the West African region registers an average annual regression of forest and savannah areas of −0.66% and −0.40% respectively between 1975-2000 against −1.08% and - 0.87% for 2000-2013. For the same periods, there have been increases in the agricultural areas from +2.32% in 2000 to +2.49% in 2013. In some localities of Benin, the 40% increase in the area of cultivated land leads to an average increase of 10% in runoff. In others, deforestation at the 50% threshold has no significant difference in water resources. The hydrological responses of the basins depend on the initial surface conditions and on the diversity of the models used.