Acta Geographica Sinica ›› 2014, Vol. 69 ›› Issue (7): 1002-1012.doi: 10.11821/dlxb201407012

• Orginal Article • Previous Articles     Next Articles

Temporal and spatial variations of snowfall in the east of Qinghai-Tibet Plateau in the last 50 years

Haoran HU(), Ling LIANG   

  1. Institute of Plateau Meteorology, CMA, Chengdu 610072, China
  • Received:2014-01-02 Revised:2014-03-17 Online:2014-07-20 Published:2014-07-20
  • Supported by:
    National Natural Science Foundation of China, No.41205068;The research item of China Meteorological Administration, No.GYHY201006009;The research item of Sichuan Meteorological Bureau, No.2011-03

Abstract:

Based on the data set of 60 weather stations in the east of Qinghai-Tibet Plateau for the period 1967-2012 and the methods of REOF, polynomial fitting, running t-test, the temporal and spatial variations of snowfall are analyzed. Meanwhile, combined with the variation of precipitation and air temperature, the relationship between snowfall and snow cover is discussed. The results indicate the spatial distribution of annual snowfall in the eastern Qinghai-Tibet Plateau is far from uniformity, varying in the range from 1.3 to 152.5 mm. The autumn snowfall is richer in the central part than in the surrounding area, the winter snowfall shows a gradual decreasing trend from southeast to northwest, the spring snowfall shows the same spatial distribution as the annual snowfall. Based on the REOF method, the field of snowfall could be classified into eight subregions: Southern Qinghai Plateau, Northern Tibet Plateau, Qaidam Basin, the southeast edge of Qinghai-Tibet Plateau, northwest of Western Sichuan Plateau, the south edge of Qinghai-Tibet Plateau, northeast of Qinghai Plateau and the valley in Southern Tibet Plateau. As a whole, in the eastern Qinghai-Tibet Plateau, except for autumn, the snowfall shows the obvious interdecadal change, namely, the snowfall was little before the mid-1980s, rich from the late 1980s to the late 1990s, and became little again after the end of the 20th century. By using running t-test method, winter snowfall shifted from the little stage to the rich stage in 1986, the snowfall in winter and spring shifted from the rich stage to the little stage in 1997. Also, in different subregions, the temporal variation of snowfall shows different characteristics. There is close relationship between snowfall and snow depth in the east of Qinghai-Tibet Plateau. The spring snowfall is influenced significantly by air temperature, followed by autumn and winter snowfall. Different from the shift of spring rainfall from the little stage to the rich stage at the end of 20th century, spring snowfall exhibited the shift from the rich stage to the little stage because of the rise of air temperature.

Key words: Qinghai-Tibet Plateau, snowfall, temporal and spatial variations