• Climate and Environmental Change •

Spatial and temporal variations and controlling factors of potential evapotranspiration in China: 1956-2000

GAO Ge1,2, CHEN Deliang1,2, REN Guoyu1, CHEN Yu1, LIAO Yaoming1

1. 1. Laboratory for Climate Studies, National Climate Center, China Meteorological Administration, Beijing 100081, China
2. Regional Climate Group, Earth Sciences Centre, Göteborg University, Göteborg, Sweden
• Received:2005-05-19 Revised:2005-08-02 Online:2006-03-25 Published:2006-03-25
• Supported by:

Chinese Ministry of Water Resources: Special Study to Water Resources Comprehensive Planning of China; Ministry of Science and Technology of China, No.2001BA611B, Sida and STINT

Abstract:

Based on the climatic data of 580 stations in China during 1956 and 2000, potential evapotranspiration are calculated using the Penman-Monteith Method recommended by FAO. The spatial and temporal distributions of the potential evapotranspiration over China and the temporal trends of the regional means for 10 major river basins and whole China are analyzed. Through a partial correlation analysis, the major climate factors which affect the temporal change of the potential evapotranspiration are analyzed. Major results are drawn as follows: 1) The seasonal and annual potential evapotranspiration for China as a whole and for most basins show decline tendencies during the past 45 years; for the Songhua River Basin there appears a slightly increasing trend. 2) Consequently, the annual potential evapotranspirations averaged over 1980-2000 are lower than those for the first water resources assessment (1956-1979) in most parts of China. Exceptions are found in some areas of Shandong Peninsula, western and middle basins of the rivers in Southwest China, Ningxia Hui Autonomous Region as well as the source regions of the Yangtze and Yellow rivers, which may have brought about disadvantages to the exploration and utilization of water resources. 3) Generally, sunshine duration, wind speed and relative humidity have greater impact on the potential evapotranspiration than temperature. Decline tendencies of sunshine duration and/or wind speed in the same period appear to be the major causes for the negative trend of the potential evapotranspiration in most areas.