高纬度林区干雷暴与雷击火时空分布特征及其相关分析

Temporal and Spatial Distribution Characteristics of Dry Thunderstorm and Lightning Fire and Their Correlation in High Latitude Forest Area

为进一步明确干雷暴天气过程中雷击火防范重点,采用2006—2015年大兴安岭山脉东北部高纬度林区闪电定位数据、逐小时降水量数据和雷击火数据,构建网格数据确定干雷暴阈值,采用ArcGIS对干雷暴和雷击火的时空分布特征进行分析,并研究其相关性。结果表明,研究区内雷击火主要发生在5—7月,占2006—2015年雷击火总数量的86.2%,高频月份为7月。发生过雷击火区域的面积占总面积的13.26%,雷击火高频区域为漠河县、呼中区和新林区,雷击火发生地域具有聚集性和重复性。干雷暴主要发生在7月。干雷暴高发区呈双带状分布,漠河县中东部、塔河县西南部、呼中区东北部、新林区和松岭区大部分为干雷暴的高发区域。干雷暴发生后48 h内为雷击火防范的重点时段;高频干雷暴相邻区域内,260~460 m的针叶林和草甸低山阳坡为雷击火防范的重点区域。

In order to understand key points of lightning fire prevention during dry thunderstorm weather,using 2006-2015 lightning location data,hour-by-hour rainfall data,and lightning fire data of the high-latitude for‐est area in the northeastern part of the Daxing'an Mountains from 2006—2015,grid data were constructed to determine dry thunderstorm threshold,temporal and spatial distribution characteristics of dry thunderstorms and lightning fires were analyzed by ArcGIS and their correlations were studies.Results showed that lightning fires happened in May,June and July,which accounted for 86.2%of total linghtning fires from 2006—2015.High-frequency month was July.Areas where lightning fires occurred accounted for 13.26%of the total area,and high frequency areas of lightning fires were Mohe county,Huzhong district and Xinlin district.Lightning fires occurred with aggregation and repetition.Dry thunderstorms mainly happened in July.Dry thunderstorm high-incidence areas showed double-belt distribution,with central and east of Mohe county,southwest of Tahe district,northeast of Huzhong district,and most part of Xinlin district and Songling district as high-incidence areas.48 hours after dry thunderstorms occurred should be key period for lightning fire prevention,and 260-460 m low mountain slopes with coniferous forests and meadows in high-frequency dry thunderstorm neighbor‐hood areas should be key areas for lightning fire prevention.