龙卷风风灾的调查与评估

THE SURVEY AND EVALUATION OF TORNADOES

以江苏省为例搜集并核实了最近３７年间龙卷风的事实和灾情资料，尝试性地采用专家评分方式从风灾实况对各次龙卷风的强度进行了富土达级别评定。论证了这种从具有模糊性的灾情事实中提取半定量信息方法的客观性。结果发现，各强度级别龙卷风的累积分布可近似用两段指数函数拟合。在此基础上，定量地给出了江苏省龙卷风频率和强度的地域分布、各级龙卷风的平均再现间隔年数等统计指标。

The data of hazardous wind events caused by tornadoes for recent 37 years in Jiangru Province are collected and confirmed. Large number of the degree's students, who played the role ofindependent evaluators, were involved into the classification of the tornadoes according to Fujita tornado scale. Statistics based upon classified results indicate the objectivity of collecting quantitativeinformation from fuzzy facts of tornado events. The analyses shows that the cumulative frequency of tornados with intensities can be well fitted by a two-segment exporiential function. In this paper theprobabilities and the expected intervals of each Fujita tornado scale are given for diffelent area ofJiangsu Province.