Abstract
We integrate Global Positioning System displacements, Gravity Recovery and Climate Experiment gravity data, reservoir water volumes, and snowpack to estimate change in subsurface water in California. We find 29% of precipitation infiltrates mountain soil and fractured bedrock each autumn and winter and is lost in the spring and summer by evapotranspiration and lateral subsurface flow either within mountain watersheds or into California's Central Valley. The Central Valley lost groundwater at 2.2 ± 0.7 km3/yr from 2006 to 2021, with 68% of the loss occurring in the southern third of the Valley. Water in Central Valley fluctuates each year by a mean of 10.7 ± 1.1 km3 with maximum water in April (not August). A third of Central Valley groundwater lost during recent severe drought is recharged during subsequent years of heavy precipitation. Of the 50 km3 of water entering Central Valley each year, 28 km3 comes from rivers, 17 km3 from precipitation, and 5 km3 from mountain groundwater.
| Original language | English |
|---|---|
| Article number | e2022GL099583 |
| Journal | Geophysical Research Letters |
| Volume | 49 |
| Issue number | 22 |
| DOIs | |
| State | Published - Nov 28 2022 |
Funding
The authors are grateful to Geoff Blewitt, Corne Kreemer, and Bill Hammond for making GPS positions publicly available; to Paul Ries, Mike Heflin, and Willy Bertiger and others on Jet Propulsion Laboratory's GPS geodesy team for making GPS satellite orbits and clocks and the GipsyX software publicly available; to Dennis Lettenmaier for knowledge on land surface hydrology models; to Jean-Philippe Avouac, Kristel Chanard, and Stacy Larochelle for constructive feedback on distinguishing between phenomena deforming solid Earth; and to Yuanjin Pan and an anonymous reviewer for constructive feedback. This research was supported by grants NASA NNH18ZDA001N-ESI NASA, NASA NNH19ZDA001N-ESI, and National Science Foundation 2021637. Part of this research was performed at Jet Propulsion Laboratory, California Institute of Technology, under NASA contract. The authors are grateful to Geoff Blewitt, Corne Kreemer, and Bill Hammond for making GPS positions publicly available; to Paul Ries, Mike Heflin, and Willy Bertiger and others on Jet Propulsion Laboratory's GPS geodesy team for making GPS satellite orbits and clocks and the GipsyX software publicly available; to Dennis Lettenmaier for knowledge on land surface hydrology models; to Jean‐Philippe Avouac, Kristel Chanard, and Stacy Larochelle for constructive feedback on distinguishing between phenomena deforming solid Earth; and to Yuanjin Pan and an anonymous reviewer for constructive feedback. This research was supported by grants NASA NNH18ZDA001N‐ESI NASA, NASA NNH19ZDA001N‐ESI, and National Science Foundation 2021637. Part of this research was performed at Jet Propulsion Laboratory, California Institute of Technology, under NASA contract.
| Funders | Funder number |
|---|---|
| 2021637 | |
| National Aeronautics and Space Administration | NNH19ZDA001N‐ESI |
Keywords
- Central Valley
- GPS
- GRACE
- groundwater
- recharge
- subsurface water