According to the findings of a couple of new studies published on Tuesday, more than one-third of the world’s largest groundwater basins are getting depleted faster than they are being refilled. The more alarming fact is that still researchers haven’t succeeded in gathering accurate data showing the amount of water left in those basins.
Researchers examined the 37 biggest aquifers the world currently has using data collected by NASA satellites. They discovered that eight of the 37 aquifers are getting depleted without any natural replenishment and another five are “highly” or “extremely stressed” as sufficient water is not flowing back into them for offsetting the amount of water drained.
According to the study, northern Africa, Saudi Arabia, Pakistan and India are home to aquifers that are under maximum stress.
The findings of the study are giving birth to substantial sustainability concerns as many places such as California rely significantly on groundwater in times of massive droughts.
UC Irvin’s graduate student Alexandra Richey, who happens to be the lead author of the studies, said that it’s already known that the amount of water getting drained is much more than the amount being replenished, which throws up the question “How long do we have before we can’t do that anymore”. She added that people on this planet keep on extracting water without knowing the exact answer to this question, which is truly terrifying.
Previously, a number studies on groundwater storage has relied on numbers; those studies were primarily based on the amount of water derived from the ground. However, according to the researchers conducting these new studies, those limited estimates are inadequate for improving groundwater management.
The studies conducted by Richey and her team used data collected by NASA satellites over a period of 11 years. Some additional factors considered during the studies include climatic conditions, how water is used, population of the area in question, etc.
Climate Experiment (GRACE) and Gravity Recover are the two satellites orbiting the Earth for measuring water’s gravitational pull. The disparity in measurements represents the amount of water the aquifers are gaining or losing.
According to Richey, these satellite data-based studies are just the beginning; extensive, on-ground research will be required for finding out the amount of water these aquifers have left in them.