Groundwater stored in aquifers across the globe may face declines of over 0.5 metres per year in the 21st century, according to international researchers who conducted an analysis of around 170,000 monitoring wells in over 40 countries. The team found that 36% of aquifers were declining by 0.1 metres per year, while 12% were declining rapidly at rates that exceeded 0.5 metres per year, and 30% of aquifers had experienced accelerated depletion in the 21st century. The team notes that 6% of aquifers also rose by 0.1 metres and 1% rose by 0.5 meters per year, and these may be the result of reductions in groundwater consumption, implementation of groundwater consumption policies, surface water transfers, changes in land cover, and managed recharge projects.
Funder: This material is based on work supported by the National
Science Foundation under grant nos. EAR-2048227 and EAR-2234213. This research was
supported by funding from the Zegar Family Foundation. This material is based on work
supported by the U.S. Geological Survey (USGS) through the California Institute for Water
Resources (CIWR) under grant/cooperative agreement no. G21AP10611-00. The views and
conclusions contained in this document are those of the authors and should not be interpreted
as representing the opinions or policies of the USGS/CIWR. Mention of trade names or
commercial products does not constitute their endorsement by the USGS/CIWR. R.G.T.
acknowledges the support of a fellowship (ref. 7040464) from the Canadian Institute for
Advanced Research under the Earth 4D programme. S.J. acknowledges the Jack and Laura
Dangermond Preserve (https://doi.org/10.25497/D7159W), the Point Conception Institute and
the Nature Conservancy for their support of this research.
From: Springer Nature
Rapid groundwater declines in many aquifers globally (N&V) *IMAGES & VIDEO*
Groundwater stored in aquifers across the globe may face declines of over 0.5 metres per year in the 21st century, an analysis of around 170,000 monitoring wells published in Nature reveals. These aquifers, however, can recover following policy changes and improved aquifer management, amongst other initiatives.
Aquifers are a crucial source of freshwater for farms, homes, industries, and cities across the world. However, aquifers across the globe may be becoming less accessible owing to changes in Earth’s climate as well as excessive water usage, threatening economies and ecosystems. While satellite maps of groundwater provide some insight into storage trends, in situ measurements from monitoring wells and analysis of those wells at a global scale can offer scientists and governments a more comprehensive look at aquifer depletion trends.
Scott Jasechko and colleagues analysed approximately 170,000 groundwater monitoring wells in over 40 countries to project aquifer trends into the remainder of the 21st century. In defining 1,693 aquifer systems across the planet, the researchers found that 36% of aquifers were declining by 0.1 metres per year, while 12% were declining rapidly at rates that exceeded 0.5 metres per year. In comparing these findings to groundwater depletion data from 1980 to 2000, the team found that 30% of the studied aquifers faced accelerated depletion in the 21st century, especially in dry regions.
The researchers also found that 6% of the aquifers in the data rose by 0.1 metres per year, while 1% rose at a rate of 0.5 metres per year. The authors propose that this growth trend could be a result of reductions in groundwater consumption, implementation of groundwater consumption policies, surface water transfers, changes in land cover, and managed recharge projects.
Jasechko and colleagues note that the sample analysed in this research is not a randomized sample of global groundwater wells, and that combining different sets of in situ measurements could provide even clearer trends over a wider area.