Variations in droughts over China: 1951-2003

摘要

The Palmer Drought Severity Index (PDSI) was calculated by using monthly air temperature and precipitation in China during the period 1951 to 2003. For the country as a whole, there are no long-term upward or downward trends in the percentage areas of droughts ( defined as PDSI < - 1.0). However, significant increases of drought areas are found in North China. Most northern China (except western Northwest China) has experienced severe and prolonged dry periods since the late 1990s, when in some of the areas the extreme drought situations were unprecedented during the period of study. Since these regions are relatively dry areas, frequent drought stress in recent decades has become more serious.