Satellite data show world's groundwater basins being depleted
IRVINE, Calif. -- Satellite data show people are overdrawing water from some of the world's largest groundwater basins.
Researchers from the University of California, Irvine say it's unclear how much water is left in the most overburdened aquifers. The problem is expected to worsen with climate change and population growth.
Using measurements taken by NASA's twin Grace satellites, scientists found the most overstressed groundwater basins were located in the driest regions.
Arabian Aquifer System in the Middle East, which serves more than 60 million people, was considered the most stressed in the world followed by the Indus Basin aquifer of northwestern India and Pakistan.
The farm-rich Central Valley in California was considered highly stressed.
According to CBS Washington, researchers found that 13 of the planet's 37 largest aquifers were being depleted while receiving little to no recharge. Eight were classified as "over-stressed," with nearly no natural replenishment to offset usage. Five were found to be "extremely" or "highly" stressed. Those aquifers were still being depleted but had some water flowing back into them.
Scientists say the total remaining volume of the world's usable groundwater is poorly known, with estimates that often vary widely. The total volume is likely far less than rudimentary estimates made decades ago, however.
"Given how quickly we are consuming the world's groundwater reserves, we need a coordinated global effort to determine how much is left," said UCI professor and principal investigator Jay Famiglietti, who is also the senior water scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.
The two studies were published online Tuesday in Water Resources Research, a journal of the American Geophysical Union.