Seasonal and aridity influences on the relationships between drought indices and hydrological variables over China

Abstract In recent decades multiple drought indices have been developed to quantify drought characteristics and to examine drought effects. However, little is known about regional applicability of drought indices for monitoring seasonal droughts over China. Here we investigated the capacity of three commonly used drought indices (SPI, SPEI and scPDSI) for showing water deficit as compared to independent precipitation, root zone soil moisture (SM) and terrestrial water storage (TWS) estimates collected from satellite observation and model simulation, by using trend and correlation analysis of the drought indices and hydrological variables in different seasons and climatic zones from 2000 to 2019. Our results suggested that areas with a significant increasing trend in precipitation (p