Spatiotemporal evolution of the droughts and floods over China

Abstract

Based on the global Palmer drought severity index (PDSI) data and monthly precipitation data from China, using linear trend analysis, comparative analysis and EOF methods, the spatiotemporal evolution of the droughts and floods over China during 1961–2010 has been analyzed. Results show that: The decadal spatial distribution of PDSI in spring is similar to that in year-round. The regional differences of PDSI in summer and autumn are obvious, especially in autumn. According to the linear analysis, climate in North China, Northeast China, Southwest China, South China and East China is becoming dry obviously; while the west of Northwest China is becoming wet. The PDSI in summer from 1961 to 2010 is also analyzed by experience orthogonal function (EOF). Results show that droughts and floods occur frequently in China since the 1980s and the intensity of droughts and floods is also increased, especially droughts in the North China, Southwest China, Northeast China and floods in East China.