Monitoring of the temporal and spatial variation of groundwater storage in the Three Gorges area based on the CORS network

- The variation of monthly groundwater storage was studied in the Three Gorges area based on CORS and gravity stations.
- The variation of groundwater storage was obtained in a high resolution of 2′ × 2′ based on loading deformation theory.
- The results were compared with the water level from groundwater monitoring wells.

The variation of groundwater storage is not well understood due to the complex hydrodynamic environment in the Three Gorges area. The variation of monthly groundwater storage from January 2011 to June 2015 was directly inverted in the Three Gorges area of China based on 26 Continuously Operating Reference Station (CORS) and eight gravity stations with a resolution of 2′ × 2′ using the Earth's gravity field and the load deformation theory. The results were then compared with the water level from groundwater monitoring wells. The comparison indicates that it is possible to calculate the temporal and spatial variation of groundwater with high precision based on the continuous observation data of CORS and a small amount of gravity stations. Our analysis shows that the groundwater storage was consistent in the Three Gorges area from 2011 to 2014. The Three Gorges Reservoir has a large impact on the variation of groundwater storage. The variation of the groundwater storage derived from CORS agrees well with that of the groundwater monitoring wells. The new data are important references for the research of hydrodynamic environmental change in the Three Gorges area and for the analysis of the impact of water impoundment and drainage in the Three Gorges Reservoir.