NASA’s twin-satellite mission known as GRACE has helped scientists estimate how much water is being depleted from the world’s major aquifers, but there is great uncertainty about how much water these aquifers hold. Image courtesy of NASA.
The 37 largest aquifers in the world. Those colored in red and orange are the most stressed. Knowledge is limited about how much water these aquifers contain. Image courtesy of University of California-Irvine.