en.wikipedia.org/wiki/Well
1 correction found
A study concluded that of ~39 million groundwater wells 9-20% are at high risk of running dry if local groundwater levels decline by less than five meters, or – as with many areas and possibly more than half of major aquifers – continue to decline.
The cited 2021 global well study reported 6–20% of roughly 39 million wells at risk, not 9–20%.
Full reasoning
This sentence appears to refer to the 2021 Science study on global groundwater wells. But authoritative summaries of that study consistently state 6–20%, not 9–20%, of the roughly 39 million wells were at risk of running dry if groundwater levels decline by only a few meters.
The American Association for the Advancement of Science (AAAS), in its release about the paper, says the authors found that "between 6 to 20%" of wells are no more than 5 meters deeper than the local water table. The University of California, Santa Barbara summary of the same study likewise says "6 to 20%" of the wells in the global sample were at risk.
So the article's 9–20% figure is not a rounding difference; it changes the lower bound reported for the study's results.
2 sources
- Groundwater wells worldwide run risk of running dry | EurekAlert!
Jasechko and Perrone found that between 6 to 20% are no more than 5 meters deeper than their current local water table, suggesting that millions of wells are at risk of drying up if groundwater levels decline by only a few meters.
- The largest assessment of global groundwater wells finds many are at risk of drying up | UC Santa Barbara
They found that 6 to 20% of the wells in their global sample were at risk of running dry if water levels continue to decline by just a few meters.