Over 1 billion people live in areas where groundwater is disappearing faster than it can be replenished, according to a new study published in Nature. Groundwater serves as an important source of water for drinking and agriculture. However, the current rate of groundwater use in regions known for their agricultural production exceeds the ability to renew this precious resource.
Researchers from McGill University and Utrecht University arrived at their results using a global hydrologic model and data on groundwater use. Utilizing this method of calculation, they approximated not only how much groundwater is being used in almost 800 aquifers the world over, but also the rate at which each aquifer renews its supply of water, known as “recharge.” This information enabled the scientists to figure out the groundwater footprint for each aquifer analyzed. The study concluded that nearly one-fifth of the aquifers around the world are experiencing significant stress due to excessive exploitation.
Led by McGill hydrogeologist Tom Gleeson, the team produced what is likely “the first water-stress index that actually accounts for preserving the health of the environment,” according to Dr. Jay Famiglietti, director of the UC Center for Hydrologic Modeling and star of the 2011 water crisis documentary, Last Call at the Oasis.
While this study marked a major step forward in understanding the delicate balance between water consumption, aquifer capacity, and ability to recharge, there remain significant gaps in the amount of aquifer data available. Yet, Gleeson found hope in the fact that virtually all of the fresh water on earth comes in the form of groundwater, presenting humankind with a unique opportunity to manage its use in a sustainable fashion starting now. Such a task will no doubt prove increasingly important as climate change causes more frequent droughts and the global population continues to expand apace.
Images: Nature, Wikimedia Commons