基于LIS／OTD格点数据的中国东北地区雷击火时空分布

Spatial and temporal distribution of lightning fire in Northeast China based on LIS/OTD grid data.

东北是中国雷击火发生最频繁的地区,因此有必要研究该地区的闪电活动规律。本文根据美国NASA提供的LIS/OTDv2.2格点资料,并结合雷击火的时空分布,用东北地区的气象资料、DEM数据和植被数据,分析了雷击火发生的原因。结果表明,从空间上来看,闪电在呼伦贝尔盟和黑河地区活动频繁,而雷击火在大兴安岭、呼伦贝尔盟和黑河地区分布较多;从时间上来看,闪电7月最集中,而雷击火6月最多。可见,闪电与雷击火在空间分布上大致一致,大兴安岭闪电活动不多,但雷击火频繁发生,可能的主要原因是地形起伏大、受大气环流影响容易形成干暴雷、易燃物分布广泛;闪电与雷击火在时间分布上有明显差别,可能的主要原因是7月较6月降水多、相对湿度大、风速小,不容易着火。

Lightning fire is highly frequent in Northeast China. Based on the Lightning Imaging Sensor （LIS）/Optical Transient Detector （OTD） data provided by the National Aeronautics and Space Administration （NASA）, and by using the regional meteorological data, DEM data, and vegetation data, this paper analyzed the spatial and temporal distribution and related affecting factors of lightning fires in Northeast China. Spatially, lightning activity was more frequent in Hulunbeier and Heihe, and lightning fire was more concentrated in Daxinganling, Hulunbeier, and Heihe. Temporally, lightning peaked in July, while lightning fire peaked in June. Therefore, the spatial distributions of lightning activity and lightning fire were generally coincided. Daxinganlin had less lightning activity but frequent lightning fire, possibly because the greater undulation of topography, easy formation of thunderstorm under effects of atmospheric circulation, and wide distribution of combustible vegetative cover. The greater differences in the temporal distribution of lightning activity and lightning fire were mainly due to the more precipitation, higher relative humidity, and smaller wind velocity in July than in June.