Recharge map

The map of spatially distributed long-term (1970-2020) average (LTA) annual groundwater recharge (mm/a) was derived by applying a fitted linear mixed model with LTA rainfall as predictor, and incorporating published ground-based studies from 134 sites across Africa, which were subject to a rigorous quality assurance procedure (MacDonald et al., 2021). Recharge estimates are more uncertain in wetter areas of coastal West Africa, where there have been limited recharge studies Source: BGR, BGS, BRGM, EAWAG & UNESCO