Fig. 4: Population density and croplands in areas of high aquifer vulnerability.
From: Groundwater vulnerability to pollution in Africa’s Sahel region
a,b, The area of high aquifer vulnerability (high tritium) from Supplementary Fig. 10a, which corresponds to the main model result (Fig. 2), was combined with the population density in 2020 based on a ‘middle-of-the-road’ shared socioeconomic pathway48 (a) and the cropland designation of land use49 (b). Population and croplands not associated with vulnerable aquifers are not shown. BF, Burkina Faso; BN, Benin; CAR, Central African Republic; GB, Guinea–Bissau; LB, Liberia; SL, Sierra Leone; TG, Togo.
