Abstract
The Yangtze River Basin (YRB), home to around 400 million people, boasts
of abundant water resources and significant spatial heterogeneity.
Revealing the driving factors of water storage changes in YRB is
essential for effective water resource management and sustainable
development. In this study, we assess the drivers of total water storage
(TWS) changes derived from the Gravity Recovery and Climate Experiment
(GRACE) satellite within YRB from two perspectives: water balance and
water storage components, including snow water equivalent (SWE), surface
water storage (SWS), soil moisture storage (SMS), and groundwater
storage (GWS). We also investigate the influence of reservoirs (e.g.,
Three Gorges Reservoir (TGR)), lakes (e.g., Dongting, Poyang, and
Taihu), and glacier thawing on regional TWS changes. The results reveal
an apparent increasing trend in YRB’s TWS from 2002 to 2022, while
trends in precipitation, evapotranspiration, and runoff do not
adequately account for this observed trend. In addition, our findings
show that the increased TWS primarily occurs during the non-monsoon
season, characterized by limited precipitation. The analysis of water
components shows that the rise in TWS within YRB is predominantly
attributed to GWS accumulation. SWS also contributes to the increasing
TWS, primarily driven by the reservoir filling. The filling of TGR
explains the observed TWS increase in Hubei province, whereas Lake
Poyang accounts for about 30% of the positive TWS trend in Jiangxi
province. Our comprehensive analysis systematically unveils the drivers
of water storage changes in YRB, providing valuable insights for its
sustainable water resource management and utilization.