“In most cases, we do not know how much groundwater exists in storage,” write the authors of a study published last month in Water Resources Research (WRR), a journal of the American Geophysical Union. ... One-third of the world’s 37 largest aquifers are highly stressed to over-stressed, according to a companion study published in the same issue of WRR. ... Scientists at the University of California, Irvine led both studies, with doctoral student Alexandra Richey serving as lead author.

National Geographic
National Geographic