Temporal And Spatial Distribution Of Lightning Activity&Correlation To Underlying Surface In Shandong Province

First, based on the lightning location data from13lightning location system stations in Shandong Province from2007to2011, spatial and temporal distribution of lightning activity is discussed and analyzed in this paper. Then, the underlying surface data of Shandong Province, such as altitude, topography, vegetation, are applied to analyze the impact on lightning activity. Final, we analyze lightning risk zoning with the statistical data, economic losses and casualties and so on, of Shandong Province from2004to2012. The results are given as following.(1) Shandong negative cloud-to-ground(CG) lightning activity frequency (98.3%) is significantly higher than the frequency of positive CG (1.7%). Due to the relatively high altitude, in the south of Jinan, Laiwu and Heze southwestern regions, lightning distribution density is relatively high. Lightning mainly actives from June to August period and usually positive flashes occur from April to August. Diurnal variation of lightning activity showes a typical double-peak and single-valley form with the peak at16:00-18:00and0:00-2:00and the valley in10:00-12:00. Most CG flashes only include the first return stroke and the peak current mainly ranges from lOkA to30kA. Negative CG first return stroke peak current is10kA, accounted for48.72%of total negative CG flashes. The first positive CG Return strokes peak current reaches20kA and the proportion to positive CG flash is about54.40%.(2) Lightning density in Shandong Province is of positive correlation to the average altitude, but the diurnal variation of lightning activity is not very clear in the low altitude area. In the high-altitude area there is a peak value of lightning activity during16:00-22:00. Positive and negative CG flash current with the increase of the height above sea level have a strong rising trendency. Vegetation in temperate coniferous forest zone, lightning activity is affected by altitude and the average CG flash density achieves maximum in the zone. In addition, in the area vegetation with the characteristc of "two or three crops a year, two crops deciduous upland fields and orchards", due to human activities, the average ground flash density is relatively high. At the boundary between two different vegetation, more lightning activity occurs, and with the increase of the frequency, the average lightning current has a decreasing intense trendency.(3) The lightning disaster in various cities of Shandong is related, not entirely determined, by the frequency of lightning activity, and by many other factors as population density, economic and other relevant characteristics. Shandong lightning disaster vulnerability is of obvious differences in various regions. The areas of high vulnerability are mainly located in center of Shandong. Jinan, Laiwu and Rizhao can be divided into highest vulnerability zones to lightning disaster; Zibo and Heze belong to high vulnerability areas; Linyi, Qingdao and Jinan are moderate vulnerability regions; Dezhou, Weifang, Yantai, Zaozhuang, Weihai and Taian are low vulnerability zones; Dongying, Binzhou and Liaocheng are lowest vulnerability zones.