京津冀区域龙卷风灾害特征分析

基于气象报表、中国气象灾害大典、气象灾情数据库以及档案馆地方志等历史资料,查阅1956—2016年京津冀区域的龙卷风个例,按照"增强藤田级别"龙卷风强度等级分类标准,采用专家评定法对龙卷风个例进行定级,并运用时间序列、趋势分析和空间分析方法,对龙卷风的时空分布、灾害特征进行了统计分析。主要结论如下:①1956—2016年,京津冀区域共确认龙卷风个例188个,空间分布上,龙卷风发生最多的区域有2个,一是张家口坝上4县:张北、尚义、沽源、康保,二是京津冀东部地区,特别是沧州、天津、唐山、秦皇岛沿海地区是龙卷风高发区;②时间分布上,1985—1993年龙卷风发生次数最多,90年代以后呈下降趋势;③龙卷风在夏季发生次数占总数的81.9%,龙卷风主要发生时段为11:00—20:00;④对有灾情记录的122个龙卷风个例,经专家评定,EF4和EF3级各1例,EF2级14例,EF1级52例,EF0级54例。

Disaster Characteristics of Tornadoes in Beijing Tianjin Hebei Region

The wind events caused by tornadoes from 1956 to 2016 in the Beijing Tianjin Hebei region are evaluated and classified by means of the expert evaluation method according to the Enhanced Fujita Scale, based on the weather reports, the Handbook of China Meteorological Disasters, the meteorological disaster database, local chronicles in archives centers and other relevant historical documents. The spatial temporal distribution and disaster characteristics of tornadoes are analyzed through the methods of time series analysis, trend analysis and spatial analysis. The main results show that there were 188 tornadoes confirmed in the Beijing Tianjin Hebei region from 1956 to 2016. In the spatial distribution, there were two areas where tornadoes occurred mostly: Zhangbei County, Shangyi County, Guyuan County and Kangbao County of Zhangjiakou; the eastern part of Beijing Tianjin Hebei region, especially the coastal areas of Cangzhou, Tianjin, Tangshan and Qinhuangdao. In the temporal distributions, the highest occurrence frequency of tornadoes was the period of 1985 to 1993 and then tornadoes started to decrease after the 1990s. Tornadoes occurred mostly in summer, which accounts for 81.9%, and occurred mainly from 11:00 to 20:00. As for the 122 tornadoes with detail disaster records, based on the Enhanced Fujita (EF) Scale, the results of expert evaluation and classification are: 1 in EF4, 1 EF3, 14 EF2, 52 EF1 and 54 EF0.