贵州地区地闪的分布特征及防护效率分析

Lightning Characteristics and Protective Efficiency in Guizhou Area

通过对ADTD闪电定位系统2007-2011年在贵州地区监测到的2631725次闪电资料,统计分析了贵州地区地闪特征及其直击雷防护效率,为该地区的雷电防护工程设计和雷电风险评估提供参考依据。结果表明:贵州地区年均地闪次数526345次;正地闪和负地闪的次数分别占总地闪数的3.6%、96.4%;平均地闪强度为38.0kA,平均负地闪强度为37.4kA,平均正地闪强度为54.2kA。正地闪的高频发生时段主要在18时至次日05时,负地闪集中出现在15时至次日02时,发现正地闪频次明显落后于负地闪3个小时的现象。闪电频次最高是毕节市,可达93479次/a,地闪密度最高是六盘水市,达到5.3次/(a.km2)。贵州地区按第一、二、三类防雷建筑物设计安装时,直击雷保护范围绕击率分别为0.02%、0.47%和6.86%,反击率分别为0.45%、1.08%和3.17%。

A statistical analysis is made of 2631725 lightning flashes monitored by the ADTD lightning location system in Guizhou between 2007 and 2011, with focus on the analysis of the lightning characteristics and protective efficiency. The results show that the annual mean number of cloud-ground lightning flashes in the Guizhou area is 526345; the positive and negative lightning respectively accounts for 3.6%, 96.4% of the total; the average lightning intensity is 38.0kA, the average positive lightning intensity is 54. 2kA, and the average negative lightning intensity is 37.4kA. The high frequency of positive cloud-ground lightning time concentrated mainly in 18 - 05 the next day, negative lightning concentrated in 15--02 the next day, there was a flash frequency and obviously behind the negative lightning 3 hours phenomenon. Lightning frequency is highest in Bijie, up to 93479 times / A. Lightning density is highest in Liupanshui, reaching 5.3/ （ a/km2 ）. According to the three-grade lightning protection category, the shielding failure rate is 0.02% , 0.47% and 6.86% , and the counter-attack rate is 0.45% , 1.08% and 3.17% respectively. The results can be used as references in lightning protection engineering design and lightning risk assessment.