Study on the change of terrestrial water storage in the Yangtze River basin based on the fusion of gravity satellite and terrestrial water data

In order to overcome the shortcomings of GNSS vertical displacement data or GRACE/GRACE-FO gravity satellite data in the inversion of terrestrial water storage changes, this paper, based on the generalized tricorner hat method, uses the generalized tricorner hat method to invert the terrestrial water storage changes, a method for retrieving terrestrial water storage by fusing GNSS vertical displacement and GRACE/GRACE-FO gravity satellite data is proposed. The vertical displacement time series of 106 GNSS CORS stations in the Yangtze River basin are selected and fused with the GRACE/GRACE-FO gravity satellite inversion water storage data in the Yangtze River basin, and compared with the GLDAS data, the performance of this method is verified. The results show that the inversion results of GNSS and GRACE/GRACE-FO fusion and GLDAS generally have high consistency. On the time scale, the regional correlation coefficient is 0.91, and the root mean square is 5.89, the Dongting Lake and adjacent areas, the northeast of the Yangtze River basin and the middle and upper reaches of the Yangtze River have high consistency, while other parts of the Yangtze River basin have differences, which may be affected by groundwater fluctuations in the region. The results show that the fusion of GNSS and GRACE/GRACE-FO can be used as means to retrieve groundwater.