Groundwater beneath High Mountain Asia shrinking by 24.2 billion tonnes annually

An international team led by Prof. Shudong Wang employed an AI-driven model that fuses multiple satellite observations and Earth-system simulations to map groundwater storage in High Mountain Asia over the past twenty years. Their analysis reveals an annual reduction of about 24.2 billion tonnes, with roughly two-thirds of the area experiencing declines from 2003 to 2020. The most severe losses occur in heavily populated downstream river basins—Ganges-Brahmaputra, Indus and Amu Darya—where irrigation pulls heavily on the resource.

Climate influences, especially changes in the cryosphere, explain nearly half of the observed variation, while human extraction has grown increasingly important after 2010. A projected surge in glacier melt may temporarily ease the drop around the 2060s, but this buffer is expected to vanish, leading to faster depletion if current water-use patterns persist. The findings, published in Environmental Research Letters, were validated against thousands of well measurements and supported by Chinese national research funding programs.