大兴安岭林区瞭望塔空间分布对雷电活动的影响OA

[Objective]Lightning activity frequently occurs in the Daxing'anling region,and the spatial distribution of forest fire lookout towers plays an important role in shaping lightning characteristics.The revelation of this impact pattern is of great significance for optimizing tower siting and layout,improving lightning protection design,and reducing the risk of lightning-induced forest fires.[Method]Based on three-dimensional lightning monitoring data(2018-2020),spatial distribution data of forest fire lookout towers,and geographic information data in the Daxing'anling Mountains,the inverse distance weighting(IDW)method in ArcGIS was applied to interpolate lightning density and current intensity,thereby revealing the spatial distribution characteristics of regional lightning activity.A circular buffer ranging from 0 to 1 km and annular buffer zones of 0-1,1-2,2-3,3-4,4-5,and 5-6 km were constructed around each fire lookout tower.Combined with spatial overlay,point distance analysis,and nearest neighbor analysis,the characteristics of cloud-to-ground lightning density and intensity within different buffer zones were quantitatively analyzed.Furthermore,towers were grouped according to elevation,and the characteristics of lightning activity around them under different elevation gradients were examined.One-way ANOVA was used to test the significance of differences in lightning parameters under varying buffer radii and elevation conditions.[Result]1)From 2018 to 2020,the annual mean cloud-to-ground lightning density in the Daxing'anling Mountains was 0.913 events·km-2a-1,and the lightning density generally showed a north-high and south-low spatial pattern,with most areas exhibiting an annual mean lightning current intensity greater than 20 kA.2)Within the 0-1 km buffer zone of fire lookout towers,the mean lightning current intensity of negative flashes,positive flashes,and total cloud-to-ground flashes was 45.05,27.11,and 28.97 kA,respectively,significantly higher than those in the outer buffer zones.No cloud-to-ground lightning events were detected within 23.26 m radius around the observation tower,reflecting to some extent the shielding effect of lightning protection devices.However,lightning intensity exhibited a clear enhancement in areas close to the towers.3)The elevation distribution of fire lookout towers had a significant influence on surrounding lightning activity.Across all elevation ranges(200-1 800 m),the mean intensity of positive flashes was higher than that of negative flashes,while the frequency of negative flashes was significantly greater.When towers were located above 1 200 m,the mean lightning current intensity was significantly higher than that in other elevation ranges,reaching a maximum within the range of 1 600-1 800 m.[Conclusion]The spatial distribution of forest fire lookout towers alters the characteristics of surrounding lightning activity to some extent,exhibiting both an attraction effect and localized enhancement effect on lightning.Lightning occurrence density and intensity within the 0-1 km buffer zone are higher than those in other zones,and lightning intensity is particularly pronounced around high-elevation towers.It is recommended to strengthen lightning protection facilities for towers located in high-elevation lightning hotspots and to incorporate lightning risk factors into tower planning and layout,thereby reducing the probability of lightning-induced forest fires and enhancing disaster prevention and mitigation capacity in forest regions.