Observed controls on resilience of groundwater to climate variability in sub-Saharan Africa.

Groundwater in sub-Saharan Africa supports livelihoods and poverty alleviation, maintains vital ecosystems, and strongly influences terrestrial water and energy budgets. Yet the hydrological processes that govern groundwater recharge and sustainability-and their sensitivity to climatic variability-are poorly constrained. Given the absence of firm observational constraints, it remains to be seen whether model-based projections of decreased water resources in dry parts of the region are justified.

Constraining groundwater modeling with magnetic resonance soundings.

Magnetic resonance sounding (MRS) is a noninvasive geophysical method that allows estimating the free water content and transmissivity of aquifers. In this article, the ability of MRS to improve the reliability of a numerical groundwater model is assessed. Thirty-five sites were investigated by MRS over a ∼5000 km(2) domain of the sedimentary Continental Terminal aquifer in SW Niger.