新疆克孜勒苏柯尔克孜自治州大气降水时空变化特征

Spatiotemporal Change of Precipitation in Kizilsu Kirghiz Autonomous Prefecture,Xinjiang,China

利用新疆克孜勒苏柯尔克孜自治州气象观测基本(准)站1960—2011年的降水观测资料,采用线性回归分析、趋势分析、突变检验和小波分析等方法,对降水量变化特征进行分析。结果表明:近52 a克孜勒苏柯尔克孜自治州年降水量均呈现一致的增加趋势。就年际变化而言,平原区阿图什站的降水量自20世纪末增加较为明显;山区乌恰站和阿合奇站降水量呈现快速增加趋势,在进入90年代后各地多极端天气气候事件;阿图什和乌恰站的降水变率较大,阿克陶和阿合奇站降水变率较小,各个观测站四季降水变率均在0.3以下,表明降水稳定;平原站年降水量序列在20世纪80年代末和21世纪初发生了2次明显的突变,突变时间点分别为1987年和2000年,山区站年降水量序列在20世纪90年代初发生了由少到多的突变,突变时间点为1994年;小波分析结果显示:克孜勒苏柯尔克孜自治州平原地区降水存在着3 a、7 a和8 a左右的振荡周期,而山区存在着8 a和4 a左右的振荡周期。

In this study,the linear regression analysis,trend analysis,Mann-Kendal abrupt change analysis and wavelet analysis were used to analyze the characteristics of precipitation variation in Kizilsu Kirghiz Autonomous Prefecture,Xinjiang,China during the period of 1960- 2011 based on the meteorological data observed by the meteorological stations in the autonomous prefecture. The results showed that precipitation in the study area in recent 52 years was in an increase trend. At decadal scale,precipitation in the plain areas was in a significant increase trend from the end-1990 s. Simultaneously,precipitation at Artux Meteorological Station in the mountainous region increased rapidly,and more extreme weather events observed by the Wuqia and Akqi meteorological stations in the mountainous regions occurred frequently from the 1990 s. Variability of precipitation observed by the Artux and Wuqia meteorological stations was high,but it was low at the Akto and Akqi meteorological station,the variability of seasonal precipitation was below 0. 3,which indicated that precipitation was stable at these stations. Two apparent abrupt changes of precipitation occurred over the plain areas in 1987 and 2000 respectively,and an abrupt increase of precipitation in the mountainous regions occurred in 1994. The wavelet analysis showed that there were about 3-year,7-year and 8-year fluctuation periods of precipitation in the plain areas and about 8-year and 4-year ones in the mountainous regions.