新疆沙尘暴的趋势和突变研究

 采用新疆77个站1961—2005年沙尘暴日数资料,使用Mann-Kendall趋势统计检验方法、最大熵谱分析,突变的t检验等方法分析了南北疆沙尘暴变化的趋势、周期和突变以及与气候变化的关系。结果显示：①南疆和北疆45 a沙尘暴趋势是减少的,南疆减小的趋势比北疆的强,两者趋势值是-0.25和-0.06,都通过了α=0.01的显著性水平检验,减少趋势中心分别位于南疆皮山、安得河附近和天山中段南北坡,20世纪80年代的减少趋势最大。②南疆和北疆低于45 a平均趋势值的年份大多集中在近20 a;南疆沙尘暴的周期分别为2.9 a和2.8 a,北疆为3.4 a和2.3 a。准3 a周期变化是南疆和北疆所共有的特征。③南北疆年沙尘暴日数与气温和降水呈反相关关系,与大风呈正相关关系,与大风的相关性最高;在南北疆,沙尘暴与气温、降水的相关性显著水平不同。受南北疆大风和降水量出现突变以及平均气温趋势出现明显转变影响,南北疆沙尘暴日数都在1987年出现突变。

Study on Sandstorm Trend and Abrupt Change in Xinjiang

The trend, periods and abrupt change of sandstorm variation and the correlations between sandstorm variation and climate change were analyzed based on annual sandstorm days of 77 stations in Xingjian from 1961 to 2005 and with methods of Mann-Kendall trend test, maximum entropy spectrum and abrupt t-test. The results indicate: ①The sandstorm frequency trend is decreased in Xingjiang since 1961, the average trends are -0.25 and -0.06 in south and north of Xinjiang respectively, the decreased trend in south of Xinjiang is stronger than that in north of Xinjiang. The centers of decreased trend locate in Pishan, Andehe and both sides of middle Tianshan Mountains; the maximum decreased trend is in 1980's. ②The years when the trend is smaller than the average are mostly in recent 20 years; The sandstorm change periods are 2.9 years and 2.8 years in south of Xinjiang and 3.4 years and 2.3 years in north of Xinjiang; the quasi-periods of 3 years is common in Xiniang. ③The correlation is negative between sandstorm and temperature, precipitation, whereas positive between sandstorm and gale, and the positive correlation is closely high. The correlation significance level is different between sandstorm and temperature, precipitation in south and north of Xinjiang. As effect of gale and precipitation abrupt in 1987 and obvious temperature change during 1980s, the sandstorm frequency variation experienced abrupt changes in 1987 both in south and north of Xinjiang.