2007~2025年日照市地闪时空分布及雷电流强度特征分析

Analysis of the Spatiotemporal Distribution of Ground Flashes and Lightning Current Intensity Characteristics in Rizhao City (2007~2025)

摘要: 利用山东省闪电定位系统2007年1月~2025年12月的地闪监测资料，对日照市地闪活动的时空分布及强度特征进行了统计分析。结果表明：① 空间分布上，日照市年平均地闪密度为1.62次·km⁻²·a⁻¹，属雷电一般易发区；高值区呈斑块状分布于西部山区及中东部沿海丘陵地带。② 时间变化上，年际变化呈“先降后升”趋势，2007年为峰值年(25,667次)，2014年为谷值年(946次)；季节变化显著，夏季(6~8月)地闪占比高达87.02%，其中8月占比47.89%；日变化呈双峰型，主峰为15~20时，次峰为01~03时。③ 强度特征上，地闪平均电流为16.92 kA，正闪平均电流(22.91 kA)显著高于负闪(15.88 kA)，正闪占比14.67%；电流强度主要集中在0~30 kA区间，历史极值为199.6 kA。本研究可为日照市雷电灾害风险评估、防雷工程设计及气象防灾减灾提供科学依据。

Abstract: Utilizing the ground flash detection data from the lightning location system in Shandong Province from January 2007 to December 2025, a statistical analysis was conducted on the spatiotemporal distribution and intensity characteristics of ground flashes in Rizhao City. The results indicate: ① In terms of spatial distribution, the annual average ground flash density in Rizhao City is 1.62 times·km⁻²·a⁻¹, classifying it as a moderately lightning-prone area. High-value zones are patchily distributed in the western mountainous regions and the hilly coastal areas of the central and eastern parts. ② Temporal variations show an “initial decline followed by an increase” trend over years, with 2007 as the peak year (25,667 flashes) and 2014 as the trough year (946 flashes). Seasonal variations are pronounced, with ground flashes accounting for 87.02% in summer (June–August), and August alone contributing 47.89%. Diurnal variations exhibit a bimodal pattern, with the primary peak from 15:00 to 20:00 and the secondary peak from 01:00 to 03:00. ③ In terms of intensity characteristics, the average ground flash current is 16.92 kA. Positive flashes (22.91 kA) significantly exceed negative flashes (15.88 kA), with positive flashes accounting for 14.67%. The current intensity is primarily concentrated in the 0~30 kA range, with a historical extreme of 199.6 kA. This study provides a scientific basis for lightning disaster risk assessment, lightning protection engineering design, and meteorological disaster prevention and mitigation in Rizhao City.