Abstract：We quantitatively analyze the drought events in the Yangtze river basin from 2003 to 2021 by using GRACE data to explore the feasibility of satellite gravimetry in monitoring regional drought. Firstly, we use five GRACE data products(CSR_SH, JPL_SH, GFZ_SH, CSR_M and JPL_M) released by three centers to retrieve the terrestrial water storage anomaly(TWSA) in the Yangtze river basin, and calculate the terrestrial water storage deficit(WSD) and water storage deficit index(WSDI). We then compare the results of five data products in combination with meteorological drought data(SPI, SPEI and scPDSI). Lastly, we analyze the drought events in the Yangtze river basin from 2003 to 2021. The results show that GRACE data products released by different centers have a certain impact on quantifying drought severity in the Yangtze river basin. WSDI has the significant correlation with SPEI on 6-month time scale, with the highest correlation coefficient of 0.66 and the lowest correlation coefficient with scPDSI of 0.54. Precipitation is a dominated factor affecting the change of terrestrial water storage in the Yangtze river basin. The most serious drought event in the Yangtze river basin occurred in the summer and autumn of 2019. The drought intensity was 2.31 and lasted for 10 months. The cumulative loss of water storage reached 415 Gt. The spatial distribution of WSDI of this drought event shows it was most serious in September 2019, with extreme drought areas. WSDI can reflect the temporal and spatial variation of drought distribution in the Yangtze river basin and play an important role in monitoring global and large-scale regional drought.
ZHAO Yaxian,ZHANG Zizhan,ZHENG Shuo et al. Comparison of Satellite Gravimetry of Terrestrial Water Storage Anomaly and Drought Indices in the Yangtze River Basin[J]. jgg, 2023, 43(2): 121-127.
