Assessment and attribution of China's droughts using an integrated drought index derived from GRACE and GRACE-FO data

Different definitions of drought from multiple perspectives complicate drought studies. Studying droughts from an integrated perspective helps to better understand their evolutions and driving factors, but few studies have taken such a comprehensive approach in China. This study conducted an assessment and attribution analysis of droughts across China from 2002 to 2020 based on an integrated drought index derived from observed terrestrial water storage (TWS) data. First, the latest solution of satellite gravimetry data was employed to analyze spatiotemporal changes in TWS deficits. Second, droughts associated with TWS deficits were detected using the Water Storage Deficit Index (WSDI). Third, an attribution analysis was conducted using the stepwise regression method to determine the driving factors of droughts. The results show that China's TWS decreases at a significant rate (−1.79 ± 0.43 mm/yr, P © 2021 Elsevier B.V.