NASA’s GRACE satellite system has sent back data indicating that 37 of Earth’s largest underground aquifers are under serious stress.
For over a decade NASA has been conducting research on the world’s groundwater aquifers by using satellites to record subtle changes in Earth’s gravitational pull, indicating where the weight of water underground exerted more pull. The data’s results do not paint a good picture.
Several parts of the world are currently going through a drought and depend on underground waters to fill in the gaps that aren’t being met by rain and snowfall.
“This has really been our first chance to see how these large reservoirs change over time,” said Gordon Grant, a research hydrologist at Oregon State University to The Washington Post. Grant was not involved in the NASA study.
Of the troubled 37 aquifers, 21 had passed the sustainability tipping point. In the decade that the study covered, those 21 had more water removed from them than put back in. Further use of the aquifers at the current rate will only continue to make the situation worse and dry out groundwater sources.
The most stressed aquifer overall, suffering the most severe depletion with little sign of recovery, was the Arabian Aquifer that provides water to Saudi Arabia and Yemen. Within the United States the worst was the Central Valley Aquifer in California, which has been limping through a debilitating drought. The water has been extracted in order to irrigate the Central Valley’s many farms, but pulling too much could cause the ground to become unstable and result in even more problems for California’s agriculture down the line.
Some groundwater regulation legislation is already in the works and in places like California and India to try and rein in the problem, but time and further research will show if they are effective in revitalizing the water supply.