干旱区生态环境知识资源中心

Using monthly meteorological observation data at 633 sites in China during 1961-2012, the drought severity change has been investigated in terms of the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) with potential evapotranspiration estimated by the Penman-Monteith equation (SPEI_pm). Significant wetting appeared to have occurred in northwestern corner of China (Xinjiang Province), especially in winter. The middle to northeastern Tibetan Plateau also experienced wetting in the last 52 years in general. Significantly, drying occurred in Central China (mostly in the middle Yellow River basin) and southwestern China (Yunnan-Guizhou Plateau) in spring and in autumn. There is no evidence of an increase in drought severity over China taking the whole country into account. On the contrary, the hyper-arid and arid zones got significantly wetter in the last 52 years as indicated by both SPI and SPEI.