资源环境科技发展态势分析平台

The self-calibrating Palmer drought severity index (scPDSI) was computed based on the four atmospheric reanalysis data sets combined with observational data over China during 1980-2015. The discrepancies of scPDSI among the four reanalysis data sets show the necessity of integrating multiple data sets. Drought characteristics, such as drought area, severity, duration, and frequency were examined based on multi-data set mean scPDSI. The results reveal that significant drying trends are found in Qinghai-Tibet Plateau, southwest, southeast and entire China. Drought area (drought severity) has increased (decreased) by about 1.16% (0.015%) per decade over entire China. Trends in drought duration, temporally averaged severity and frequency also indicate that droughts become more serious in each region during the past 36 years. The identification of drought events in each month by the clustering algorithm shows that droughts over China are more and more frequent. In addition, 65 separate drought events with the duration longer than 3 months were identified under the area threshold of 150,000 km(2). Through severity-area-duration analysis, the 2005-2015 drought is found to be the prominent event.