Fresh water is one of the most important resources in the world. Now, researchers from the University of California, Irvine, believe that it is being depleted at a faster rate than it can naturally be replenished.
They are warning that there is little to no data on how much water is left in these aquifers.
Alexandra Richey, the lead author of two studies that were published in the Water Resources Research journal, wrote that researchers had collected satellite data from NASA and examined the 37 largest aquifers in the world. The weight of the water affects the Earth’s gravitational pull, called dips and bumps, and this is what the researchers looked at between the years 2003 and 2013.
Earth’s largest groundwater aquifers are rapidly depleting:
They found that the Arabian Aquifer System was the most overstressed in the world, which is worrying as it’s an important water source for more than 60 million people. The Indus Basin aquifer of northwestern India and Pakistan came in second place, and the Murzuk-Djado Basin in northern Africa was third. Researchers suggest that 21 of the world’s 37 largest groundwater sources have already passed their sustainability tipping points, wrote IFL Science.
“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.”
It is the first time researchers have used data from space to characterize groundwater losses. They used readings that were generated by NASA’s twin GRACE satellites. The most overused were in the world’s driest areas, which rely heavily on underground water. Climate change and population growth are also expected to intensify this problem.
“What happens when a highly stressed aquifer is located in a region with socioeconomic or political tensions that can’t supplement declining water supplies fast enough?” asked Richey in a statement, “We’re trying to raise red flags now to pinpoint where active management today could protect future lives and livelihoods.”
California farms turn to well drilling to combat drought:
According to The Washington Post: “California’s Central Valley Aquifer was the most troubled in the United States. It is being drained to irrigate farm fields, where drought has led to an explosion in the number of water wells being drilled. California only last year passed its first extensive groundwater regulations. But the new law could take two decades to take full effect.”
“As we’re seeing in California right now, we rely much more heavily on groundwater during drought,” Famiglietti said. “When examining the sustainability of a region’s water resources, we absolutely must account for that dependence.”
The study notes that the dearth of groundwater is already leading to significant ecological damage, including depleted rivers, declining water quality, and subsiding land. Groundwater aquifers are typically located in soil or deeper rock layers beneath the Earth’s surface. The depth and thickness of many make it tough and costly to drill to or otherwise reach bedrock and learn where the moisture bottoms out. But it has to be done, according to the authors.
“Given how quickly we are consuming the world’s groundwater reserves, we need a coordinated global effort to determine how much is left,” Famiglietti added.