呼和浩特地区40a沙尘天气时空分布规律及演变趋势

文章利用呼和浩特地区1971—2010年扬沙、沙尘暴资料,采用线性倾向估计、多项式拟合、经验正交函数分解、小波分析、Mann-Kendall检验、滑动t检验、Yamamoto法等分析了1971—2010年呼和浩特地区扬沙、沙尘暴日数的时空分布特征及演变规律。结果表明：⑴呼和浩特各地区扬沙、沙尘暴日数空间分布具有高度的一致性,由西到东呈现出高—低分布特点。⑵春季（3—5月）是扬沙、沙尘暴天气现象最频发季节,不频发时段是秋季（9—10月）,沙尘暴的季节分布基本上是春多秋少。⑶从年际分布特征来讲,扬沙、沙尘暴日数总体呈现显著地下降趋势,但在总体下降的同时到21世纪初期又有所上升。⑷扬沙日数序列研究时段内显著存在着5~8a周期振荡;沙尘暴日数序列的周期特征不明显。⑸通过突变检测得知：沙尘天气在20世纪70年代末、80年代初开始突变减少,之后整体呈现波动减少的趋势。⑹20世纪70年代呼和浩特地区扬沙、沙尘暴发生最多,80年代沙尘天气在逐步减少,90年代达最少,到了21世纪前10年扬沙、沙尘暴发生日数均较20世纪90年代有所增多。

Spatial And Temporal Distribution And Evolution Tendency of Sand-dust Storm in Hohhot in Recent 40 Years

Based on duststorm observations during 1971—2010 years from 6 meteorological stations,this paper analyzed temporal and special distribution characteristics and evolution law using linear trend estimate value、polynomial fitting、EOF、wavelet analysis、Mann-Kendall test、moving t-test、yamamoto method.The results showed that：（1） The sand-dust storm days in space distribution with a high degree of consistency,from west to East exhibits a high-low distribution characteristics in Hohhot.（2）The sand-dust storm is most frequently accrued in the spring and lest frequently in the autumn.（3） Annual variation analysis showed that the sand-dust storm has significantly decreased in general,at the same time has risen to the early twenty-first Century.（4） The elevating sand days has 5～8a periodic oscillation;Cycle characteristic is not obvious of sand-dust storm days.（5） The mutation detection showed that the sand-dust storm days were reduced in the late 1970s and the beginning of 1980＇s.The sand-dust storm days were most happened in 1970s,and gradually reduced in 1980s.To the 1990s,sand-dust storm days were the lest,but increased in 2000s.