基于LLS的雷电流参数随海拔变化特征分析

Characteristics Analysis of Lightning Current Parameters Changing with Elevation Based on the Lightning Location System(LLS)

雷电流参数是防雷工程设计和雷电灾害风险评估必不可少的基础参数.针对重庆地区闪电定位监测网获取的地闪资料(1999-2008年),利用GIS获取其高程属性,重点分析雷电流幅值、地闪密度、正闪比例以及不同雷电流幅值比例随海拔的变化规律.结果表明:雷电流幅值随着海拔的上升而增大;正负极性地闪密度随海拔的上升呈幂指数减少;正闪比例在低海拔(<1 000m)地区随着海拔的上升而下降,而在高海拔(>1 000m)地区随着海拔的上升而增加;低幅值(0～100kA)闪电比例随着海拔的上升而下降,而高幅值(100～200kA)闪电比例随着海拔的上升而增加.在此基础上,获得了雷电流参数与海拔变化的关系式,为雷电防护技术提供科学依据.

The parameters of lightning current are indispensable fundamental parameters of lightning protection engineering design and risk assessment of lightning.Based on the ground lightning data（1999-2008） recorded by the lightning location monitoring network of Chongqing and the elevation attributes of the region obtained with GIS,this paper focuses on the analysis of the variations of lightning current amplitude,cloud-ground flash density,positive lightning proportion and different lightning current amplitude proportion with altitude.The results show that lightning current amplitude increases with altitude;ground flash density of positive and negative polarity decreases exponentially with increasing elevation;positive lightning proportion declines with increasing elevation at lower elevation（1 000 m） and increases with it at higher elevation（1 000 m）;and lower amplitude（0-100 kA） lightning proportion drops with increasing elevation,while higher amplitude（100-200 kA） lightning proportion rises with increasing elevation.Based on these results,a relationship expression of lightning current parameters and altitude variations is established,which may provide a scientific basis for lightning protection technology.