新疆绿洲区沙尘暴变化特征及气象因子影响分析

新疆绿洲农业区是世界上受风沙危害最严重的地区之一。文中采用Mann-Kendall非参数趋势检验法、跃变检测等方法,对新疆绿洲农业区54a来沙尘暴演变趋势及气象因子对其影响进行了分析。结果表明:(1)近54a来,研究区沙尘暴发生次数均呈负趋势变化,其中,库车、和田、阿克苏、喀什以及莎车等地沙尘暴发生次数减少趋势尤为显著,而且沙尘暴发生次数越多的地区,其减少趋势越明显;(2)除巴音布鲁克之外,大部分研究区均在80年代前后出现显著跃变,即80年代之后沙尘暴发生次数均少于80年代之前;(3)研究区沙尘暴的年持续时间均呈逐年下降趋势,而且沙尘暴发生次数越多、总持续时间越长的地区,沙尘暴的年持续时间减少趋势越显著;(4)降水距平百分率、日降水量≥0.1mm日数与沙尘暴发生次数均呈反相关关系,且后者相关性要稍高;除巴音布鲁克外,其余地区的年平均风速、年最大风速与沙尘暴发生次数均为正相关,除和田外,年平均风速与沙尘暴发生次数的相关性比年最大风速要高些;除石河子外,其余地区年平均相对湿度均与沙尘暴发生次数呈反相关。

Changes of sandstorm occurrence and meteorological impact factors in Xinjiang oasis agricultural area

Xinjiang oasis agricultural area is one of the most serious damaged area by dust and sand weather in the world.In this paper,Mann-Kendall non-parametric test method and Cumulative deviation test were used to analyze the variation of sandstorm and meteorological data from 1954 to 2007 in Xinjiang oasis agricultural area.Results show that(1) All the frequency of sandstorms showed a negative trend in 54 years,in which,Kuqa,Hotan,Aksu,Kaxgar and Yarkand showed significantly reduced trend.The areas where sandstorms occurred more,the negative trend went more extraordinary;(2) All other areas appeared a significant jump around 1980s except Bayinburuke,in another word,sandstorm occurred after 1980s less than it happened before 1980s;(3) Sandstorm duration time showed negative trend too.The areas where sandstorms occurred more,the negative trend of duration time went more extraordinary;(4) Percentage of relative variability of precipitation and the days with daily precipitation ≥0.1mm were all negative interrelated with sandstorm occurrence,and the negative interrelation was more significant between days with daily precipitation ≥0.1mm and sandstorm occurrence.The annual average wind speed and annual highest wind speed were all positive interrelated with sandstorm occurrence in all other areas except Bayinburuke,and the relation was more significant between the annual average wind speed and sandstorm occurrence except Hotan.The annual average relative humidity and sandstorm occurrence were negative interrelated in other areas except Shihezi.