Journal of Geographical Sciences ›› 2009, Vol. 19 ›› Issue (2): 153-163.doi: 10.1007/s11442-009-0153-6

• Climate and Environmental Change • Previous Articles     Next Articles

Water vapor transport over China and its relationship with drought and flood in Yangtze River Basin

JIANG Xingwen1, LI Yueqing1, WANG Xin2   

  1. 1. Institute of Plateau Meteorology, China Meteorological Administration, Chengdu 610071, China|
    2. Climate center of Sichuan Province, Chengdu 610071, China
  • Received:2008-07-22 Revised:2008-10-19 Online:2009-04-25 Published:2009-04-25
  • Supported by:

    International Technology Cooperation Project of the Ministry of Science and Technology of China, No. 2007DFB20210; Application Technology Research and Development Project of Sichuan Province, No. 2008NG0009; Basic Research Foundation of Institute of Chengdu Plateau, China Meteorological Administration, No.BROP2000802

Abstract:

The characteristics of water vapor transport (WVT) over China and its relationship with precipitation anomalies in the Yangtze River Basin (YRB) are analyzed by using the upper-air station data in China and ECMWF reanalysis data in summer from 1981 to 2002. The results indicate that the first mode of the vertically integrated WVT is significant whose spatial distribution presents water vapor convergence or divergence in the YRB. When the Western Pacific Subtropical High (WPSH) is strong and shifts southward and westward, the Indian Monsoon Low Pressure (IMLP) is weak, and the northern part of China stands behind the middle and high latitude trough, a large amount of water vapor from the Bay of Bengal (BOB), the South China Sea (SCS) and the western Pacific forms a strong and steady southwest WVT band and meets the strong cold water vapor from northern China in the YRB, thus it is likely to cause flood in the YRB. When WPSH is weak and shifts northward and eastward, IMLP is strong, and there is nearly straight west wind over the middle and high latitude, it is unfavorable for oceanic vapor extending to China and no steady and strong southwest WVT exists in the region south of the YRB. Meanwhile, the cold air from northern China is weak and can hardly be transported to the YRB. This brings on no obvious water vapor convergence, and then less precipitation in the YRB.

Key words: water vapor transport, drought and flood, complex EOF, Yangtze River Basin