1961—2010年阿拉善盟沙尘天气时空分布特征

The spatial distribution features of sandstorm weather in Alxa League of nearly 50 years

利用阿拉善盟1961—2010年8个站的气象观测资料,分析了近50a阿拉善盟沙尘暴、扬沙、浮尘天气的年平均、四季的空间分布特征、增减趋势及形成原因。结果表明:阿拉善盟沙尘天气的时空分布具有很强的季节和地区性差异,与地理位置、地形特征及地表生态系统等有很大的关系。沙尘暴区以拐子湖为中心向东南和西北递减,而扬沙、浮尘与沙尘暴有所不同,具有3个高值区,向四周递减,形成鞍型场。沙尘暴多发地扬沙、浮尘天气较少。四季的分布特征与年平均特征基本一致,春季最多,夏季多于冬季,秋季最少,且近50a沙尘暴发生次数呈波动性减少趋势。

Base on the datas of 8 weather stations from 1961 to 2010, this article analyzed the spatial distribution characteristics, increasing and decreasing trend and formation reasons of sand-dust storm, blowing sand, floating dust weather on annual average in different seasons. The result shows that the distribution of sand-dust weather had very seasonal and regional difference, and was influenced by geographical locations, topographic features and the ecological system of the earth＇s surface. The sand-dust storm center was located in Guaizi Lake, and it gradually decreased forward southeast and northwest of Guaizi Lake. While the blowing sand and floating dust weather was different from sand-dust storm weather, there are three high-value areas. It gradually decreased forward all around and formed to saddle field. Wherever the location for most sandstorm is seldom seen blowing sand and floating dust. Distribution features of the annual average and the seasonal average was basically same. Spring was the most, and summer was more than winter, and autumn was the least. Also nearly 50 yearn the sandstorm weather that occurred on frequency was decreasing.