Abstract: The spatiotemporal distribution,interannual variation and continuity of snowfall in the west of south Xinjiang in recent 50 years were studied using the methods of precipitation variability analysis,snowfall contribution analysis,linear trend analysis and R/S analysis based on the daily precipitation data observed by 17 meteorological stations in the west of south Xinjiang during the period from 1961 to 2010,and the data were provided by Xinjiang Meteorology Information Center. According to the topographical and climatic conditions,the west of south Xinjiang was divided into three regions,i.e. the mountainous area,northwest and southeast plain. The periodicity variation of snowfall in different regions was analyzed with Morle wavelet transform. The abrupt change of snowfall was studied through the Man-Kendall abrupt change test. Combining with a sliding T-test and signal-to-noise ratio test,the abrupt change years were determined. Results are as follows: ① The spatial distribution of snowfall was not uniform. In the west of south Xinjiang,snowfall decreased rapidly from the northwest to the southeast. Snowfall contributed less to the annual precipitation,and its contribution rate was very unstable. The interannual variation of snowfall was significant; ② The average annual snowfall in the west of south Xinjiang was in an increase trend,which was related to the snowfall intensity,but the snowfall days were in a decrease trend; ③ Spatially,the tendency rates at the stations varied in a range of -0.01-0.16 mm·a^-1. Snowfall at all the stations was in an increase trend except a slight decrease at Bachu Meteorological Station; ④ The contribution rate of slight snow decreased significantly,that of moderate snow was relatively stable,and that of heavy snow increased significantly. Moreover,the days of slight snow decreased,but those of moderate and heavy snow increased slowly; ⑤ The periodicity of low frequency was similar among different regions,but that of high frequency was different. In recent 50 years,the abrupt change of snowfall occurred in 1977 and 2000 in the western plain,but in 1995 in the mountainous area.

Key words: snowfall, spatiotemporal distribution, wavelet analysis, abrupt change test, south Xinjiang