Estimation of daily hydrological mass changes using continuous GNSS measurements in mainland China

Surface displacements measured by the Global Navigation Satellite System (GNSS) integrate elastic response of solid Earth to regional and local hydrologic loading signals provide an opportunity for near-real-time monitoring terrestrial water storage variations. Here, we estimate spectral information hydrology-induced vertical surface deformation based on spherical Slepian basis functions recover daily changes in continental over mainland China from January 2010 December 2019. Our inversion results, depending a sparsely-distributed GNSS network, indicate largest seasonal fluctuation hydrological mass loads southwestern China. The GNSS-inferred equivalent height has annual amplitude up 314 mm, which is greater than 243 mm Gravity Recovery Climate Experiment (GRACE) 150 Land Data Assimilation (GLDAS). We also find notable oscillations 153–166 middle lower Yangtze River Basin. This feature appears model GRACE Mascon solutions but invisible GLDAS model, mostly indicating existence significant that unmodeled model. There board agreement estimates derived multiple data sets South China, contrast weak temporal coherence various North demonstrate ability tracking drought wet periods, can serve as independent means characterize extremes. study emphasizes sparse network still be considered complementary tool map large-scale spatiotemporal variations benefit community assessing dynamics.