绵阳地区夏季雷电特征分析及雷电流辐值概率分布算法修正

利用四川省绵阳地区2017—2019年6—8月闪点定位系统资料，对绵阳地区闪电频次、雷电流幅值和闪电密度分布进行研究。利用GIS软件获取地闪点的高程，分析了闪电频次空间分布特征，结果表明:闪电频次随纬度增加呈先增后减趋势，随经度分布呈现双峰特征，多发生于下垫面海拔高度400~600 m区域；绵阳地区地闪密度有三个高值中心分别位于安县西桑枣和雎水、江油东北二郎庙、绵阳市游仙区杨家湾地区，结合高程分析发现地闪多发区位于山地与平原交汇处偏向低海拔一侧。分析比较了目前常用的防雷计算方法规程法和IEEE推荐公式，在此基础上对绵阳雷电流幅值数据拟合分析，提出适用于本地的雷电流累计概率分布函数和概率密度计算公式。 

ANALYSIS OF CHARACTERISTICS OF SUMMER LIGHTNING IN MIANYANG CITY AND MODIFICATION OF ALGORITHM FOR PROBABILITY DISTRIBUTION OF LIGHTNING CURRENT RADIATION

By using the lightning location data of Mianyang City from June to August during 2017—2019, the present study analyzes the lightning frequency, lightning current amplitude and lightning frequency density distribution in Mianyang. It is found that in the latitudinal direction, the lightning frequency increases first and then decreases with the increase of latitude and the longitudinal distribution is bimodal. The region which has the highest frequency is the area of 400~600m above sea level. There are three high-value centers of lightning in Mianyang, i.e., Sangzao and Jushui in the west of Anxian, Erlangmiao in the northeast of Jiangyou and Yangjiawan in Youxian District of Mianyang. By using the elevation data, we find that the ground flash usually occur at the low-altitude side at the intersection of mountains and plains. The present study analyzes and compares the currently commonly used lightning protection calculation methods. And based on that, a fitting analysis of the lightning current amplitude data in Mianyang is presented, and a lightning current amplitude accumulative probability formula and a probability density calculation formula are proposed.