Two new studies led by UC Irvine using data from NASA Gravity Recovery and Climate Experiment satellites show that civilization is rapidly draining some of its largest groundwater basins, yet there is little to no accurate data about how much water remains in them.
The result is that significant segments of Earth’s population are consuming groundwater quickly without knowing when it might run out, the researchers conclude. The findings appear today in Water Resources Research.
“Available physical and chemical measurements are simply insufficient,” said UCI professor and principal investigator Jay Famiglietti, who is also the senior water scientist at NASA’s Jet Propulsion Laboratory. “Given how quickly we are consuming the world’s groundwater reserves, we need a coordinated global effort to determine how much is left.”
The studies are the first to characterize groundwater losses via data from space, using readings generated by NASA’s twin GRACE satellites that measure dips and bumps in Earth’s gravity, which is affected by the weight of water.
For the first paper, researchers examined the planet’s 37 largest aquifers between 2003 and 2013. The eight worst off were classified as overstressed, with nearly no natural replenishment to offset usage. Another five aquifers were found, in descending order, to be extremely or highly stressed, depending upon the level of replenishment in each – still in trouble but with some water flowing back into them.