Abstract：According to the attenuation and leakage of signal caused by filtering in GRACE data post-processing, the corrective effect of forward modeling is studied using simulation data. It is revealed that the degree of correction is about 1 cm, which cannot be neglected when using GRACE to investigate terrestrial water storage variation. Based on GRACE RL05 Level-2 data from July 2002 to December 2014, the variation of water storage in the Three Gorges reservoir is investigated. The results reveal that the annual amplitude of GRACE time series before and after forward modeling is 7.0±2.4 cm and 7.2±2.7 cm respectively, and the leakage error reduces after correction. GRACE and hydrological models show obvious seasonal variations, but the annual amplitude of the GRACE is slightly larger than that of the hydrological model, since GRACE is influenced by many more factors. GRACE can detect the equivalent water height change of the Three Gorges reservoir, which are 60.2 mm, 28.3 mm and 20.5 mm respectively, showing good agreement with the water level observations. We analyze the equivalent water variation rates in the Three Gorges area from 2003 to 2009 before and after modeling, finding that the signal of water storage obviously converges after forward modeling correction.
LI Zhen,GAO Yongquan,ZHANG Chuanyin et al. Investigation of Water Storage Variation in the Three Gorges Using the Forward Modeling Method[J]. jgg, 2018, 38(9): 930-936.
