This static map shows the locations of the three existing extensometers (red) in the USGS' Virginia Extensometer Network with the location of a fourth future extensometer (green). The basemap is of the Virginia Coastal Plain and shows the severity of groundwater depletion, with darker blue indicating greater groundwater depletion.
Groundwater Level Change
![USGS extensometers are located near centers of groundwater drawdown. Groundwater levels have been falling in the VACP.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/media/images/SubsidenceFiguresComposite.png?itok=8gu2wgIS)
Detailed Description
Top left: A map of the Virginia Coastal Plain showing the locations of USGS extensometers in relation to centers of groundwater drawdown.
Bottom left: Simulated aquifer model based on the Santa Ana Coastal Basin, California, where land subsidence due to possible variations of groundwater level throughout the twenty-first century is calculated.
Top right: Groundwater withdrawal rates from Virginia Coastal Plain aquifers from 1900 to 2008. Modified from Heywood and Pope (2009).
Bottom right: Water levels in the Potomac aquifer at U.S. Geological Survey (USGS) groundwater monitoring well 55H 1 (site 372428076561501) in New Kent County, Virginia.
Sources/Usage
Public Domain.
Bottom left figure from: Shirzaei, M., Freymueller, J., Törnqvist, T.E. et al., 2021, Measuring, modelling and projecting coastal land subsidence, Nature Reviews Earth & Environment, 2(1), https://doi.org/10.1038/s43017-020-00115-x
All other figures from: Eggleston, Jack, and Pope, Jason, 2013, Land subsidence and relative sea-level rise in the southern Chesapeake Bay region: U.S. Geological Survey Circular 1392, 30 p., https://dx.doi.org/10.3133/cir1392.