Groundwater recharge occurs disproportionately from heavy rainfalls

Photo credit: Nature World News

Tropical groundwater resources may be more resilient to climate change than previously thought. Pictured here is an artesian well in central semi-arid Tanzania. (Photo : Jasechko, S & Taylor, R.G)

Tropical Groundwater Resources Benefit From Fewer, But More Intense Rainfall

By Samantha Mathewson

Tropical groundwater resources may be able to stand up to the challenges imposed by climate change, researchers from the University College London (UCL) and the University of Calgary report in a new study. Generally speaking, global warming leads to fewer but more intense rainfalls. However, this precipitation pattern seems to adequately recharge vital sources of freshwater.

Groundwater is an invaluable source of freshwater across the tropics, providing safe drinking water and a source of agricultural irrigation. It follows then, the replenishment of these sources is vital for sustaining the livelihoods and ecosystems that depend on the availability of freshwater.

For their study, researchers assessed the chemical signatures in precipitation and groundwater at 15 sites spread out across the tropics. This allowed them to compare the stable isotopes of hydrogen and oxygen found in these water molecules, from which they can interpret how heavy rainfalls impact groundwater recharge in surrounding areas. In terms of their study, heavy rainfall was defined as those exceeding the 50th percentile of local rainfall intensity. Therefore, their results suggest that groundwater recharge occurs disproportionately from heavy rainfalls, but the processes that carry intensive rainfall to groundwater systems and enhance the resilience of tropical groundwater storage as global temperatures rise remains unknown.

Read the full story: Nature World News

Author: Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.

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