Groundwater – a vital source of water for drinking and irrigation across sub-Saharan Africa – is resilient to climate variability and change, according to a new study led by Cardiff University and UCL.
Groundwater plays a central role in sustaining water supplies and livelihoods in sub-Saharan Africa due to its widespread availability of generally high quality water.
A consortium of 32 scientists from across Africa and beyond carried out the research., which involved the collation of multi-decadal records of groundwater levels and rainfall to examine how the replenishment of groundwater has responded to variations in climate and geology. The team analyzed observations compiled from nine countries across sub-Saharan Africa representing a range of climates from hyper-arid to humid.
The study shows that in humid areas groundwater is replenished primarily by rainfall that directly infiltrates the land surface, whereas in drylands it occurs predominantly by leakage from temporary streams and ponds.
Dr Mark Cuthbert, from Cardiff University’s School of Earth and Ocean Sciences and co-lead on the study, said: “Previous regional-level assessments of groundwater resources using large-scale models have ignored the contribution of leaking streams and ponds to groundwater supplies, underestimating its renewability in drylands and resilience to climate change.”
Professor Richard Taylor (UCL Geography), co-lead on the study, said: “Groundwater offers a potential pathway to sustain increases in freshwater use required to achieve UN Sustainable Development Goals 2 (zero hunger) and 6 (safe water for all).”