成渝地区雷电活动时空分布特征研究

Study on the Spatiotemporal Distribution Characteristics of Lightning Activities in the Chengdu-Chongqing Region

基于2016-2022年成渝地区闪电定位监测数据,采用数理统计、ArcGIS空间分析等方法研究成渝地区雷电活动时空分布特征。结果表明:成渝地区雷电活动主要以负闪为主,年平均占比为92.7%,负闪频次占比年变化呈显著下降趋势;季节变化明显,夏季占比最高,达76.4%,月变化曲线呈单峰型,7、8月份雷电活动最活跃;日变化呈双峰型,雷电活动主要发生在23:00至次日4:00,占比达31.7%,10:00-12:00为雷电活动谷值。雷电流幅值出现最高频次区间范围为7~17 kA,95%的雷电强度小于50 kA,90%小于40 kA。成渝地区雷电高发区主要分布在山区和丘陵地区,其中密度高值区位于重庆西南部的永川、璧山、江津、綦江以及主城区,密度普遍大于6次/km^(2) ,次高值区分布在重庆云阳、四川内江、资阳、遂宁、南充、广元的部分地方,密度普遍大于3次/km^(2) 。研究结果对成渝地区雷电监测预报预警工作提供了实质性的数据支持,尤其在夏季汛期需重点关注,以提高对雷电灾害的应对和防范能力。

Based on the lightning positioning monitoring data in the Chengdu-Chongqing region from 2016 to 2022,this study utilizes methods such as mathematical statistics and ArcGIS spatial analysis to investigate the spatiotemporal distribution characteristics of lightning activity in the region.The results indicate that negative flashes dominate lightning activity in the Chengdu-Chongqing region,accounting for an annual average proportion of 92.7%.The annual variation in the proportion of negative flashes shows a significant decreasing trend.Seasonal variations are evident,with the highest proportion occurring in summer,reaching 76.4%.The monthly variation curve exhibits a single-peak pattern,with July and August being the peak months for lightning activity.Daily variation shows a double-peak pattern,with lightning activity predominantly occurring from 23:00 to 04:00 the next day,accounting for 31.7%,while 10:00-12:00 represents the valley value of lightning activity.The most frequent range for lightning current amplitude is 7-17 kA,with 95%of lightning intensities being below 50 kA and 90%below 40 kA.High lightning incidence areas in the Chengdu-Chongqing region are mainly distributed in mountainous and hilly areas.The high-density zone is located in the southwest of Chongqing,including Yongchuan,Bishan,Jiangjin,Qijiang,and the main urban area,with a density generally exceeding 6 times/km^(2) .The second-highest density area is distributed in parts of Yunyang in Chongqing,and some areas in Neijiang,Ziyang,Suining,Nanchong,and Guangyuan in Sichuan,with a density generally exceeding 3 times/km^(2) .The research results provide substantial data support for lightning monitoring,forecasting,and warning in the Chengdu-Chongqing region,especially during the summer flood season,to enhance the ability to respond to and prevent lightning disasters.