Monitoring of Extreme Agricultural Drought of the Past 20 Years in Southwest China Using GLDAS Soil Moisture

Drought can cause severe agricultural economic losses and hinder social development. To manage drought, the process of drought events needs to be described with help an effective indicator. As a comprehensive variable, soil moisture is essential indicator for describing drought. In this work, extreme in southwest China were analysed by Global Land Data Assimilation System (GLDAS) root zone data set. define quantitatively, Standardized Soil Moisture Index (SSMI) was calculated using data, then used get duration, frequency, severity China. The results showed that frequency intensity had apparent upward trend before 2014 downward since 2014. Moreover, there are differences various regions Yunnan Province prone spring events. Guangxi Guizhou spring, autumn winter droughts, droughts significantly higher than droughts. Sichuan-Chongqing border area summer We found monthly variation different provinces consistent, but seasonal different. Meanwhile, performance SSMI compared commonly indices, Precipitation Evapotranspiration (SPEI) Palmer Severity (PDSI). more sensitive both SPEI PDSI also demonstrate GLDAS study at small regional scale.