云南墨江5.9级地震灾区雷电的危险性及其应急防御对策

Risk and Emergency Defense of Lightning in the Stricken Area of Magnitude-5.9 Earthquake,Mojiang County in Yunnan

为了深入认识雷电灾害在地震灾区的危险性,探讨地震灾区雷电灾害应急防御对策,分析了墨江5.9级地震灾区雷电活动时空分布特征及其危险性:灾区雷电易发风险呈北高南低,震中处于雷电极高易发区,年平均地闪密度为1.87次/(km^2·a),平均地闪强度为33.41 kA,7-9月地闪活动最为频繁,午后至夜间地闪活动活跃,17—19时地闪次数达到峰值。震中5 km范围内震后当月的雷电危险性等级为极高,灾区雷电危险性较大的区域是牛库村、毕库村和丙蚌村等。依据地震灾区雷电危险性等级和特点,确定应急防御对策:①应急安置点的选址避开雷击易发区域;②按照“重点防护、以点带面、示范宣传”的原则和区域防护、滚球法防护的设计理念装设应急避雷装置;③综合防御直击雷、闪电电涌侵入、接触和跨步电压的可能危害;④开展雷电灾害风险隐患排查和科普宣传。

In order to deeply understand the danger of lightning disaster in earthquake-stricken areas and discuss the emergency countermeasures of lightning disaster in earthquake-stricken areas,the spatial and temporal distribution characteristics and the danger of lightning activities in the stricken area of Magnitude-5.9 Earthquake,Mojiang County are analyzed.The results show that the degree for lightning-risk liability was higher in the northern part of the disaster area and lower in the southern part,and the highest lightning risk appeared in the epicentral area.The annual mean ground lightning density was 1.87 times/(km^2·a)in the locality and the annual mean intensity was 33.41 kA.The activities of lightning is most active from July to September,the most active time interval was afternoon and night with achieving peak value at 17∶00—19∶00.There was high level of lightning risk included Niuku Village,Biku Village,Bingbang Village and so on.According to the lightning risk level and characteristics of the earthquake-stricken region,the emergency defense countermeasures were determined as following.Firstly,the location of the emergency resettlement site should avoid lightning strike-prone areas.Secondly,according to the principle of“starting from key protection,faning out from a point to a whole area with demonstrating and propagandizing”and the concept of regional protection and rolling ball protection,emergency lightning protection devices should be designed and installed.Thirdly,comprehensive protective measures should be adopted against direct lightning strikes,lightning surge intrusion,contact and step voltage.Finally,the hidden dangers of lightning disasters should be located and eliminated while relevant scientific popularization should be conducted.