Integrating GNSS and GRACE data to estimate terrestrial water storage changes in the southwestern region
In order to address the limitations of using global navigation satellite system(GNSS)or Gravity Recovery and Climate Experiment(GRACE)/GRACE follow-on(GFO)technology alone for retrieving regional terrestrial water storage changes.A method for integrating GNSS and GRACE/GFO data to estimate changes in regional terrestrial water storage is provided in this paper,drawing inspiration from the"decomposition-reconstruction method."Changes in terrestrial water storage in southwestern China from 2012 to 2022 are estimated by integrating GNSS and GRACE/GFO data using time series data from 90 GNSS stations in southwestern China.The performance of our fusion method is verified through spatial distribution analysis and comparison with other fusion methods and precipitation data.The results demonstrate that the fusion inversion combines the advantages of GNSS and GRACE/GFO in spatial distribution.On the time scale,the inversion results from GNSS and GRACE/GFO both lag behind precipitation by 2 months,whereas the fusion inversion results lag behind precipitation by only 1 month,and the corresponding correlation coefficients are also higher than those of GNSS or GRACE/GFO inversion results.Therefore,the fusion method provided in this paper offers a reference for combining multiple data sources to obtain more reliable regional terrestrial water storage changes.
GNSSGRACE/GFOfusion inversionterrestrial water storage changesouthwest China