Two new studies show that the largest groundwater basins in the world are being drained by human consumption—but there is little information on just how much water is left.
The studies, conducted by a team of researchers from the University of California, Irvine, evaluated groundwater levels in basins around the world, also drawing upon data supplied by NASA Gravity Recovery and Climate Experiment satellites.
Between 2003 and 2013, researchers looked at the 37 largest aquifers on Earth and found eight to be “overstressed,” with no natural replenishment to offset usage. Another five were found to be “stressed”—threatened, but with some water returning to them.
The most overstressed are found in the world’s driest areas—the Arabian aquifer system and northwestern India and Pakistan—and climate change and population increase is expected to exacerbate the problem.
The accompanying study concluded that the total volume of the world’s remaining usable groundwater remains a mystery.
Both of these studies highlight a growing need to conserve and reuse water sources.