Journal of Geographical Sciences ›› 2008, Vol. 18 ›› Issue (1): 3-16.doi: 10.1007/s11442-008-0003-y

• Climate and Environmental Change •     Next Articles

Variations and trends of the freezing and thaw- ing index along the Qinghai-Xizang Railway for 1966?2004

JIANG Fengqing, HU Ruji, LI Zhen   

  1. Xinjiang Institute of Ecology and Geography, CAS, Urumqi 830011, China
  • Received:2007-08-06 Revised:2007-09-25 Online:2008-02-25 Published:2010-09-18
  • Supported by:

    Knowledge Innovation Program of Xinjiang Institute of Ecology and Geography, CAS, No.0571041

Abstract:

Annual freezing and thawing index of 7 meteorological stations along the Qing-hai-Xizang Railway were calculated based on daily maximum and minimum temperature records for 1966?2004. Trends of annual freezing and thawing index were analyzed using the Mann-Kendall test and a simple linear regression method. The results show that: 1) The mean annual freezing indices range from 95 to 2300℃·d and the mean annual thawing indi-ces range from 630 to 3250℃·d. The mean annual freezing index of the 7 stations exhibited decreasing trends with decreasing rate of ?16.6– ?59.1℃·d /10a. The mean annual thawing index of these 7 stations showed increasing trends with the related decreasing rate is 19.83–45.6℃·d /10a. 2) The MK trend test indicated the significant decreasing trends (sig-nificant at < 0.05 significant level) in the annual freezing index for most stations except for Golmud. The significant increasing trends can be observed in the annual thawing index for 4 stations except Golmud and Tuotuohe. Golmud was the only station with no trends in both annual freezing and annual thawing index.

Key words: freezing and thawing index, global warming, trends, Qinghai-Xizang Railway