A monthly and daily 0.25° groundwater storage dataset in the Yangtze River Basin by assimilating GRACE/GRACE-FO data into the W3RA hydrological model

Abstract

Dynamic and accurate assessment of terrestrial water and groundwater is crucial for water resources management, agriculture and ecological environment protection. While the GRACE/GRACE-FO satellites have proven effective in monitoring large-scale terrestrial water storage anomaly (TWSA) and groundwater storage anomaly (GWSA), this study aims to enhance their spatial and temporal resolution for detecting the small-scale TWSA and GWSA in the Yangtze River Basin (YRB). The main objectives and contents are as follows: 1) The daily/0.25° TWSA and GWSA are modeled using the W3RA hydrological model, incorporating factors such as rainfall, temperature, wind speed, and radiation; 2) The spatial correlation errors of GRACE/GRACE-FO data from 2002 to 2022 are considered, the uncertainties in the GRACE data over the YRB are obtained by the JPL; 3) The monthly and daily/0.25° TWSA and GWSA during 2002-2022 in the YRB is derived by accounting for the spatial correlation errors in the assimilation of GRACE/GRACE-FO into W3RA through the Ensemble Kalman Filter (EnKF) method; 4) Utilizing the results to quantify the spatiotemporal distribution of water resources in the YRB, the GRACE/GRACE-FO data signal serves as a valuable supplement to the model data. 5) The monthly and daily/0.25° GWSA will be further compared with in-situ well data to validate their accuracy. Furthermore, a quantitative analysis of the temporal and spatial evolution characteristics of GWSA in the YRB will be conducted.This study will provide valuable data and technical references for the dynamic monitoring of a small-scale TWSA and GWSA in the YRB and applications worldwide.