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2002 - Journal of Hydrology

The potential for satellite-based monitoring of groundwater storage changes using GRACE: the High Plains aquifer, Central US

Groundwater storage in the High Plains aquifer has been steadily decreasing for 50 or more years due to withdrawals for irrigation. This trend has been documented in annually published United States Geological Survey reports of water level changes in the High Plains aquifer, but assessments of groundwater storage changes in other parts of the world are incomplete. NASA's gravity recovery and climate experiment (GRACE) soon may provide an alternative means for monitoring groundwater changes, via satellite remote sensing. That terrestrial water storage changes are likely to be detectable by GRACE satellites has been demonstrated by prior studies. This investigation builds on those studies by evaluating the potential for isolating changes in the groundwater component of terrestrial water storage. In the High Plains, the magnitude of annual groundwater storage changes averaged 19.8 mm between 1987 and 1998. Uncertainty in deriving estimates of High Plains aquifer storage changes from GRACE observations will arise mainly from the removal, via land surface modeling, of the effects of soil moisture changes from the gravity signal. Total uncertainty is predicted to be about 8.7 mm.

2007

Comparison of seasonal terrestrial water storage variations from GRACE with groundwater‐level measurements from the High Plains Aquifer (USA)

This study presents the first comparison of seasonal groundwater storage (GWS) variations derived from GRACE satellite data with groundwater‐level measurements in the High Plains Aquifer, USA (450,000 km2). Correlation between seasonal GRACE terrestrial water storage (TWS) and the sum of GWS estimated from field measurements (2,700 wells) and soil moisture (SM) simulated by a land surface model is high (R = 0.82). Correlation between GRACE‐derived and measured GWS is also significant (R = 0.58). Seasonal GRACE‐derived TWS and GWS changes were detectable (≥ uncertainty) in 7 and 5 out of 9 monitored periods respectively whereas maximum changes (between winter/spring and summer/fall) in TWS and GWS were detectable in all 5 monitored periods. These results show the potential for GRACE to monitor GWS changes in semiarid regions where irrigation pumpage causes large seasonal GWS variations.

论文关键词

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