湖南省雷电活动及其规律的分析

Analyses of Lightning Activity and Its Law in Hunan Province

地闪活动规律是防雷工程中重要的基础资料,可以为输电线路路经的选择及采取有效的防雷措施提供参考依据。为掌握湖南省雷电活动及其规律,根据湖南省雷电定位系统2002-2010年共9a的雷电数据,统计分析了湖南的雷电流强度概率分布;结合气象观测站1997-2003年雷暴日观测记录,利用地理信息系统(GIS),采用网格法统计不同时间段和区域内的雷暴日和地闪次数,得到了湖南省雷电活动在时间、空间上的分布情况。统计分析结果表明,湖南省雷电活动在不同时间、不同地域存在明显差异,局部地区雷电活动异常强烈,地闪密度达到了6.9次/(km2.a),湖南省雷电流强度概率分布符合近似对数正态分布式。

The laws of cloud-to-ground flash activities are the important fundamental data of lightning protection engineering, which can provide a reference for the selection of transmission line route and for the lightning protection measures. On the basis of the lightning data of the lightning location system （LLS） in Hunan Province from 2002 to 2010, we analyzed the probability distribution of lightning current magnitude. Combining with the thunderstorm day records of weather observation station from 1997 to 2003, we acquired the temporal and spatial distribution of lightning activities in Hunan Province by counting the thunderstorm days and cloud-to-ground flashes in different time and different regions with the geographic information system （GIS） and grid method. Statistical results show that there exist obvious differences of cloud-to-ground flashes in different time and different regions for the lightning activities in Hunan Province. The lightning activities in some regions are intensive and the cloud-to-ground flash density reaches 6.9 flashes per square kilometer per year. The probability distribution of lightning current magnitude in Hunan Province accords with a lognormal distribution approximately.