近49a古尔班通古特沙漠南缘地区沙尘暴变化特征初探

Change characteristics of sandstorm in the southern fringe of Gurbantunggut Desert since recent 49 years

运用小波分析、累积距平、滑动t检验及灰色关联度分析等方法对1961-2009年古尔班通古特沙漠南缘沙尘暴年日数序列的变化趋势、周期特征、突变特征及与气候因子的关系进行了分析。结果表明:(1)49 a间,古尔班通古特沙漠南缘沙尘暴年日数呈波动式减少的趋势,趋势系数为-0.565。(2)沙尘暴年日数序列存在多个周期;在不同的时间尺度上,沙尘暴经历了多个频发期和少沙尘暴期,在未来几年可能会再次迎来一个沙尘暴的频发期。(3)研究区内沙尘暴年日数变化趋势确实存在1973年、1987年和2002年的突变年份。(4)灰色关联度分析表明,大风、春季大风、夏季大风、前1 a冬季温度、年均温度、春季温度6个气候因素与沙尘暴年日数序列关系最密切,是影响沙尘暴发生的主要因素。

In this paper,the trend,periods and abrupt change of sandstorm variation and the correlations between sandstorm variation and climate change were analyzed on the southern fringe of the Gurbantunggut Desert based on the dada of the annual sandstorm days from 1961 to 2009 and with methods of wavelet analysis,annual anomalies,abrupt test and the grey correlation degree.The results indicate as follows:(1)The sandstorm frequency trend is decreased during 49 years on the southern fringe of the Gurbantunggut Desert,the average trend is-0.565,which passed the significance test at 0.05 level.(2)There are the obvious periods of 5,13 and 22 years for the annual sandstorm days series;At the scale of different years,there are many high frequency and latent period for the annual sandstorm days series;Another high frequency period will be happened again in the future.(3)The years of change in annual sandstorm days are really 1973,1987 and 2002 in the study area,the trend of change periods are passed the significance test at 0.05 level,the trend is significant.(4)The grey correlated degree of 14 climate factors show that,the gale,spring gale,summer gale,dust weather,winter rainfall of last year,annual temperature,spring temperature have the high correlation extent.They are the main factors that lead to sandstorm.