中国龙卷风时空统计特性及灾情分析

Temporal-Spatial Statistical Characteristics and Disaster Analysis of Tornadoes in China

龙卷风是毁灭性的自然灾害之一,其经过之处常发生严重的破坏。针对龙卷风危害程度大但相关统计数据少的问题,本文基于《中国气象灾害年鉴》中记录的有关龙卷风的描述,对2003~2019年发生在我国境内的648次龙卷风的时间和空间特性进行统计分析,对龙卷风发生后建筑物、树木、农作物的受损情况及人员伤亡情况进行探讨,并利用熵权法综合评定的思想对龙卷风灾情进行综合评价。结果表明:我国东南沿海、东北平原及高原地区为龙卷风的常发地带;龙卷风在夏季发生的频次较其他季节高,且常发生在下午14~16时。自2003~2019年间,龙卷风导致建筑物损坏和倒塌的数量分别为282,349和86,263间,且位于我国东部地区的建筑物受损数量大于西部;龙卷风过境后,树木的失效模式主要有连根拔起、树干折断、树干倾斜及枝条折断四类,2003~2019年间树木遭受龙卷风破坏的数量累计为2,390,457棵,且位于四川、河南、江苏省的树木受损较为严重;农作物受灾、成灾和绝收面积分别为1296920.8、337,529和233,010公顷;2003~2019年龙卷风共造成388人死亡、7485人受伤,受灾人数达20,033,080人次;根据熵权法建立的龙卷风灾情综合评价模型对龙卷风灾情进行评价,得出我国华东、华南和东北地区灾情最为严重。研究结果对中国龙卷风数据库的建立和防灾减灾具有一定的参考意义。

Tornado is one of the most destructive natural disasters, often causing severe damages where it passes. The extent of the damage caused by tornadoes is significant, while the related statistical data are few. This paper presents a statistical analysis of the temporal-spatial characteristics of 648 tornadoes occurred in China from 2003 to 2019, based on the descriptions related to tornadoes recorded in Yearbook of Meteorological Disasters in China. The impacts of tornadoes on buildings, trees, crops and casualties are also discussed. A comprehensive evaluation of tornado disaster is conducted using the entropy-weighing method. The results show that the tornadoes often occur in the southeast coast, northeast plain, and the plateau areas in China. They occur most frequently in summer, between 2 and 4 pm. A total of 282,349 buildings were damaged by tornadoes, and 86,263 buildings were collapsed. And the number of buildings damaged in the eastern part of China is greater than that in the west. After the tornado passes, the failure modes of trees mainly include four types: uprooting, trunk breaking, trunk tilting and branch breaking. The number of trees damaged by tornadoes was 2,390,457 from 2003 to 2019, with severely damaged ones occurring in Sichuan, Henan, and Jiangsu provinces. The areas of crops which were affected, caused disaster and demolished are 1296920.8, 337,529, and 233,010 hectares, respectively. From 2003 to 2019, a total of 20,033,080 people were affected by tornadoes, among which 388 people were died and 7485 people were injured. Using the entropy-weighing method, a comprehensive evaluation model was established for the evaluation of tornado disaster. The results indicate that tornado disasters in East China, South China, and Northeast China are the most severely damaged areas. The research findings have certain reference significance for the establishment of a tornado database in China and disaster prevention and mitigation efforts.