Study Reveals Rapid Decline in Vital Underground Water Resources

New research, analyzing millions of measurements from over 170,000 wells in more than 40 countries, reveals a concerning depletion of underground water reserves crucial for billions of people. This global study is the first to piece together the status of groundwater levels, shedding light on the impact of human activities and climate change on this essential resource.

Groundwater, found in aquifers—permeable rock formations—is vital in regions with scarce rainfall, like northwest India and the southwest United States, providing a lifeline for drinking and irrigation. The study, published in the journal Nature, indicates that reductions in groundwater levels make it challenging for people to access freshwater, leading to potential issues such as land subsidence.

Co-lead author Debra Perrone, an associate professor at the University of California, Santa Barbara, expressed curiosity as the driving force behind the study. The researchers aimed to better understand the global state of groundwater by analyzing millions of measurements. The Ascoy-Soplamo Aquifer in Spain exhibited the fastest decline, with a median drop of 2.95 meters per year, according to study coauthor Scott Jasechko.

While the study couldn’t include data from some regions due to monitoring limitations, it encompassed countries where most global groundwater pumping occurs. Notably, success stories in addressing groundwater depletion were identified in locations like Bangkok, Arizona, and New Mexico, where interventions helped initiate recovery.

The researchers also examined data from 1980 to 2000 for 542 aquifers to assess whether declines in groundwater levels were accelerating in the 21st century. The study found that for 30% of these aquifers, declines accelerated in the first two decades of the 21st century, surpassing the rates recorded between 1980 and 2000.

Donald John MacAllister, a hydrologist at the British Geological Survey, praised the research as an impressive compilation of global groundwater data. He emphasized the importance of raising awareness among policymakers about safeguarding this hidden but critical resource to build resilience and adapt to climate change.