Humans are depleting a large portion of the world’s groundwater resources, and they are not being naturally refilled, researchers said.
The scientists at the University of California Irvine used data from National Aeronautics and Space Administration (NASA) satellites to determine drainage of the world’s largest groundwater aquifers in recent years.
{mosads}They found that a third of the 37 major aquifers were either worse off in 2013 than in 2003 or were highly stressed.
“Available physical and chemical measurements are simply insufficient,” Jay Famiglietti, the principal researcher on the project, said in a Tuesday statement. Famiglietti is both a UC Irvine professor and the top 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,” he said.
The paper was published Tuesday in the journal Water Resources Research. It is the first to use data from NASA’s Gravity Recovery and Climate Experiment, or GRACE, satellite system, which detects changes in Earth’s gravity that can show groundwater levels.
It found that the most stressed aquifers were in extreme dry areas, whose residents and businesses have leaned most heavily on groundwater.
A second study by the same team found that the actual levels of groundwater in aquifers is extremely poorly known.
“We’re trying to raise red flags now to pinpoint where active management today could protect future lives and livelihoods,” Alexandra Richey, the lead author on both studies, said in the statement.