A study by the U.S. Geological Survey (USGS) released this week has found that draw-down from long-term aquifers has been accelerating driven in large part by water use for irrigation.
These two maps, the first from the USGS report showing depletion hotspots, and the second from the United States Department of Agriculture showing the US’s main wheat growing regions, provide a clear visual of the correlation between groundwater depletion and agriculture.
According to the USGS report:
The study assessed long-term groundwater depletion in 40 separate aquifer systems or subareas to build a national overview of groundwater depletion (defined as a reduction in the volume of groundwater in storage in the subsurface). The figure below taken from the report shows the proportion of depletion due to irrigation (green shaded portion) in the Death Valley aquifer in California.
Click here to read the full report, Groundwater Depletion in the United States 1900-2008.
