Analysis of rainfall long series in non-Sahelian West and Central Africa within a context of climate variability

In the arid and semiarid areas of West and Central Africa, the scarcity of the water resources is an old and well-known notion. However, the drought, which has been observed in the tropical regions of Africa for the last two decades, shows notable harshness, persistence and extension. Annual rainfall time series registered over long duration for a set of stations all over non-Sahelian West and Central Africa have allowed the study of spatial and temporal rainfall evolution in this region. Results confirm the existence of an alternation of dry and wet periods since the beginning of the twentieth century. However, the current drought has no equivalent, neither regarding duration nor intensity, throughout the studied period. Nevertheless the strong spatial heterogeneity of the phenomenon is underlined by both a statistical study and some mapping.