A pioneering ‘global-scale’ analysis of groundwater levels by a team of researchers from the University of California at Santa Barbara (UCSB), ETH Zürich, University College London (UCL), Rutgers University and King Abdulaziz University has been published in Nature. Their article, Rapid groundwater decline and some cases of recovery in aquifers globally, is rooted in the analysis of millions of groundwater-level measurements in 170,000 wells from 1,693 aquifer systems in over 40 countries; these encompass ~75% of global groundwater withdrawals. Led by Scott Jasechko at UCSB, the team spent four years compiling, curating and analyzing this piezometric dataset of unprecedented magnitude.
Conducted at scale of individual aquifers, the study shows that rapid groundwater-level declines exceeding half a metre per year are widespread in the twenty-first century, especially in dry regions with extensive croplands. Further, they show that groundwater-level declines have accelerated over the past four decades in 30% of the world’s regional aquifers. This widespread acceleration in groundwater-level declines highlights an urgent need for more effective measures to address groundwater depletion. Crucially, the team’s work also reveals cases in which depletion trends have reversed through human interventions such as managed aquifer recharge, development of alternative water sources, or changes in the ways that groundwater policies have been implemented.
open-access article in Nature: https://www.nature.com/articles/s41586-023-06879-8
associated policy brief: Open PDF document >
video abstract: https://youtu.be/H1OhKb3qEPA
