影响北京地区的沙尘暴

利用1971－1996年的地面气象月报和地面天气图资料，借助地理信息系统，逐次分析了影响北京地区沙尘暴天气过程的演变规律，确定了影响北京地区沙尘暴天气过程的移动路径和源地。结果表明：北京地区沙尘暴主要发生在春季和初夏，以4月为最多。根据沙尘暴的起源，可将影响北京的沙尘暴天气过程分为外源型和内源型两类。沙尘暴的移动路径主要包括北路和西路两条。外源型沙尘暴的入侵地点集中在：1）内蒙古乌兰察布盟和锡林郭勒盟西部的二连浩特市、阿巴嘎旗；2）哈密市以东至内蒙古阿拉善盟的中蒙边境。内源型沙尘暴的起源地主要集中在腾格里沙漠及其周边地区。

Sand Dust Storms Invading Beijing

With the data published on Surface Meteorological Monthly Bulletin and Surface Chart during 1971-1996, the temporal variation of sand-dust storms invading Beijing is analyzed. Furthermore, the movement routines and source locations of sand-dust storms are determined in assistance with GIS. The results show: Sand-dust storms in Beijing occurred frequently in spring and early summer, especially in April. According to their source locations, the sand-dust storms are classified into two types, i. e. the internal and external-source sand-dust storm. For the external-source sand-dust storms, they always intrude Beijing from two major regions, one is the Wulanchabumeng, Erlianhaote and Abagaqi(western part of Xilin-guolemeng) of Inner Mongolia, the another is the Sino-Mongolia boundary from eastern part of Hami, to Alashanmeng. The source locations of internal-source sand-dust storms are mainly in Tenggeli desert and its surrounding areas.