NASA Study Identifies 40 Regions Where Human Activity Alters Water Storage

A NASA study identified 40 regions where human activities significantly altered terrestrial water storage trends from April 2002 to November 2025.

The research used satellite data from GRACE and GRACE-FO missions to measure changes in Earth's gravity caused by shifting water and ice. The analysis achieved five to 10 times more spatial detail than previous studies.

Scientists found human activities such as irrigation, reservoir impoundment and land-use change were significantly related to water storage trends on every nonpolar continent except Australia. In four continental regions, an anthropogenic variable showed a stronger relationship with the storage trends than any climate variable did.

Groundwater pumping drove declines in California's Central Valley, the southern High Plains of the United States, Chihuahua in Mexico, and northern India, where the decline was steeper than earlier estimates suggested. Retreating Himalayan glaciers accounted for only 15 percent of the decline in northern India.

The study also found water storage increases in areas where rainfed cropland expanded, including parts of sub-Saharan Africa and northern Brazil's Maranhão state. The Boguchany Reservoir on Russia's Angara River produced the strongest water storage trend in nonpolar northern Asia. Water gains were also detected in Turkmenistan's Karakum Desert from seepage along the Karakum Canal.

The findings were published by researchers including hydrologist Mary Michael O'Neill and deputy director Matthew Rodell at NASA's Goddard Space Flight Center.