京、津、冀区域群发性强沙尘暴分析

利用1954—2002年82个站的气象观测资料，探讨京、津、冀区域群发性强沙尘暴的认定标准，构建较完整的群发性强沙尘暴序列，并分析该地区群发性强沙尘暴的时空分布特征和气候变化趋势。近50a京、津、冀区域共出现了39例群发性强沙尘暴，河北省的冀西北高原区和石家庄、保定、衡水、沧州四市交接处饶阳一带是京、津、冀区域强沙尘暴天气的多发区。多发季节为3—5月，占全年总数的76．9％，其中4月份最多，占全年总数的51．3％。群发性强沙尘暴年代际变化呈现总体减少趋势，其发生次数、覆盖面积均是以20世纪90年代为最低值．

Analysis of Severe Group Dust-storms in Beijing,Tianjin and Hebei Province

Based on the available original dust - storms data of 82 meteorological observation stations, this paper constructed a quite complete series of severe group dust- storms in Beijing,Tianjin and Hebei region from 1954 to 2002. As a result, 39 severe group have been found and confirmed in Beijing,Tianjin and Hebei region. Based on the 39 cases, the temporal and spatial distribution characters, especially inter- decade change of severe group dust - storms were analyzed, and following viewpoint were noted: 1)The plateau in the northwest of Hebei and Raoyang area were the main areas influenced by severe group dust - storms. 2)The severe group dust-storms occured mainly in spring, accounted for 76.9% , especially in April it reached 51.3% .3) In recent 50 years, the inter-decade change of severe group dust -storms decreased in Beijing,Tianjin and Hebei region. 4)The frequency and influencing area of severe group dust - storms during 1990s were the lowest too.