Geodetic and hydrologic measurements show large-scale groundwater recovery in the North China Plain since mid-2020 after decades of depletion

Groundwater depletion and associated land subsidence in the North China Plain (NCP) have garnered significant attention. This study fused multiple Gravity Recovery and Climate Experiment (GRACE) mascon solutions and GLDAS soil moisture storage (SMS) data using the generalized three-cornered hat method to generate unified terrestrial water storage (TWS) and SMS datasets. By subtracting SMS from TWS data, we estimated the groundwater storage (GWS) changes in the NCP from 2004 to 2023. Singular spectrum analysis was then applied to extract GWS trends, revealing a significant large-scale GWS increase after mid-2020, at a rate of 5.1 ± 2.5 cm/yr, reversing ~17 yr of depletion at −2.0 ± 0.5 cm/yr in the GRACE era. In-situ groundwater level observations from 526 wells supported this increase, with rates of 0.7 ± 0.1 m/yr for unconfined aquifers and 1.1 ± 0.2 m/yr for confined aquifers. GNSS stations demonstrated reduced subsidence in sediment and slower uplift in bedrock after mid-2020, further confirming the groundwater recovery. Spatially, GRACE-based observations suggested that the regional-scale recovery signal was stronger in the southern NCP than in the northern NCP. Meteorological analysis suggested that increased precipitation in July and August, driven by anomalous anticyclones and enhanced water vapor transport, was the primary cause of the GWS recovery, contrasting with previous studies that emphasized anthropogenic factors. This change reversed five decades of groundwater depletion in the NCP and would be of great significance for water resource management and climate change studies.