Groundwater footprint highlights challenging global water situation

New measure developed for sustainability of global groundwater water supply points to overuse of water in Asia and North America. Farmers are unsustainably exploiting groundwater in a number of important agricultural regions, according to a team of researchers led by Tom Gleeson of McGill's Department of Civil Engineering, in collaboration with researchers from Utrecht University in the Netherlands. Indeed, widespread groundwater depletion has recently been reported in aquifers (the underground sand, gravel or rock formations that hold groundwater) around the world. In a recent article published in Nature , the researchers estimate that approximately 1.7 billion people, most of whom reside in Asia, live in areas where groundwater resources and/or groundwater-dependent ecosystems are under threat. By combining data of groundwater usage gathered from each nation, with global hydrology models, the researchers have developed a new way of measuring water use relative to supply in aquifers around the world. They call it the groundwater footprint. And like the ecological footprint, which has become the common measure for calculating human demands on the biosphere relative to its ability to regenerate, the groundwater footprint is designed as a location-based measure of the sustainability, or lack thereof, of human groundwater use around the planet.