GEOGRAPHICAL RESEARCH ›› 2010, Vol. 29 ›› Issue (1): 137-144.doi: 10.11821/yj2010010014

• Climate and Global Change • Previous Articles     Next Articles

Spatiotemporal variation characteristics of winter temperature in Zhangye City

ZHANG Bo, KANG Shu-yuan, LIU Yan-yan, WANG Hai-jun, WANG Ya-min, DAI Sheng-pei   

  1. Geography and Environment College of Northwest Normal University, Lanzhou 730070, China
  • Received:2008-12-29 Revised:2009-08-25 Online:2010-01-20 Published:2010-01-20

Abstract:

The meteorological data of 6 national stations covering the 49-year period from 1956 to 2004 were analyzed to understand the spatial-temporal characteristic about temperature variation in winter over Zhangye city, by employing the approach of linear trend analysis as well as Mann-Kendall rank analysis, wavelet analysis and spatial interpolation. It was observed that there was an obvious ascending tendency of winter air temperature from 1956 to 2004 at the α=0.1 significant level ( β=0.08) in this region, or a warming rate of 0.56℃/10a in winter. The result indicated that the winter temperature of this region increased by 2.8℃ in the last five decades. Besides, it was also found that the winter warming contributed 89% to that of the whole year. Compared with Northwest China and the whole country, the warming rate was similar to the former but higher than the latter. During the study period, there was a lowest average winter temperature point in 1967 and a highest one in 1987 with an abrupt change point in 1985, prior to the point was a cool stage and after it a warm stage emerged especially after 1987, which was similar to the winter temperature variation of Hexi Corridor. In the last half century, there was typical oscillation such as 6a and 22a in winter temperature variation, particularly, the 22a oscillation dominated. Spatial variation of winter temperature indicated that there was an obvious ascending tendency from southeast to northwest in the study area. By Mann-Kendall analysis it was found that six subregions showed a similar warming trend at the α=0.1 significance level, compared with the other five. Shandan station experienced the highest warming trend with β=0.21 and a warming rate 0.94℃/10a. Generally speaking, winter temperature warming mainly appeared in the last 20 years and the warming rate of the eastern part was higher than that of the western. Additionally, some problems to be solved in future were briefly analyzed.

Key words: winter temperature, Mann-Kendall method, wavelet analysis, spatial distribution, Zhangye City