拉萨市城区雷电特征与防护技术

利用拉萨市历年人工地面观测资料、闪电定位仪等资料,采用ArkGIS等软件和层次分析法,研究拉萨市城区历史雷击及雷灾情况、爆炸危险场所分布,最终划分出拉萨市城区雷灾易发区,并提出相应的防御措施。结果表明,拉萨市城区年均雷暴日数为70.5 d,月雷暴日数主要在5—9月,11月—次年3月几乎无雷暴出现,月雷暴日分布呈单峰型;雷电活动存在明显的日变化,主要出现在14∶00—次日02∶00。拉萨市城区闪电分布较为均匀,负闪电占绝大多数。雷电灾害具有发生频次多、范围广、雷暴活动期长等特点。城中、城东、城南区域为雷电灾害易发区域;城北、城西/开发区雷灾易发等级中等,柳梧新区雷灾易发等级最低。

Lightning Characteristics and Protection Technology of Urban Area of Lhasa City

Based on the artificial ground observation data and lightning location data in Lhasa City,using AirGIS software and the analytic hierarchy process,lightning stroke, lightning disaster and distribution of explosion hazardous area in urban area of Lhasa City was studied,the disaster prone areas were divided, and put forward the corresponding prevention measures.The results showed that the average number of thunderstorm days in urban area of Lhasa City was 70.5 days, and the number of monthly thunderstorm days was mainly from May to September, and there was almost no thunderstorm from November to March of next year,and the monthly thunderstorm days showed a single peak type.Lightning activity had obvious diurnal variation, mainly in 14∶00-the next day 02∶00.Lightning distribution of urban area of Lhasa City was more uniform,negative lightning accounted for the majority.Lightning disaster had many characteristics, such as frequency more, wide range and long period of thunderstorm activity.Urban, east and south of the region were lightning disaster prone areas.North and west (development zone)of the city were disaster prone middle grade, Liuwu new district was lightning disaster prone to the lowest level.