Acta Geographica Sinica ›› 2006, Vol. 61 ›› Issue (5): 519-526.doi: 10.11821/xb200605008

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Hydrological Response of Lhasa River to Climate Change and Permafrost Degradation in Xizang

GONG Tongliang1,2, LIU Changming1,3, LIU Jingshi4   

  1. 1. Institute of Water Science, Beijing Normal University, Beijing 100875, China;
    2. Institute of Water Resources, Tibetan Autonomous Region, Lhasa 850000, China;
    3. Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China;
    4. Institute of Tibetan Plateau Research, CAS, Beijing 100085, China
  • Received:2006-01-22 Revised:2006-04-02 Online:2006-05-25 Published:2006-05-25
  • Supported by:

    National Natural Science Foundation of China, No.40561002; President Foundation of CAS; National Key Project of Science and Technology of China, No.2005BA901A11

Abstract:

Air temperature in the Lhasa River basin has increased by 0.54oC since 1990, particularly in winter and autumn, while precipitation did not increase in the same period. Based on climatological data of (1963-2003) and monthly runoff data of 28 years (1976-2004), the hydrological and geoCryological response to the climate change was studied. The significant response to the temperature rising from the winter streamflow during November to February was detected, winter streamflow during December to February increased by 16% and in February by 22%. Correlation analysis between water flow and temperature indicated that the rise in temperature in oCtober and November by 0.8-0.9oC resulted in the increase in winter streamflow, the seasonal frost at depth of 0.9-1.5 m became thinner comparing with that before the 1990s, the thickness decreased by about 14 cm. The hydrological response from winter flow in a permafrost basin is more sensitive and quicker than that of air temperature. There are un-certainties due to the lack of both soil frost and snowfall survey on the Tibetan Plateau.

Key words: Lhasa River, permafrost, winter streamflow, Mann-Kendall test, correlation