摘要
地下火作为森林中一种难以控制的燃烧现象,其形成机理极为复杂。我国大兴安岭林区是森林地下火的多发地区。对该地区2002年发生的地下火研究表明:丰富的近土壤层和地下可燃物是森林地下火发生的物质条件,气象条件促进了森林地下火的发生,特别是在遇到降水少、长期干旱、地面温度增加、相对湿度降低和可燃物干燥的情况下,就很容易引起地下火灾。地下火有地理和时间分布特征。地表火主要发生在原始森林区域,如针叶林、阔叶林或针阔混交林,都有可能发生地下火。地下火一般燃烧速度慢,持续时间长,燃烧充分,具有隐蔽性强、燃烧不连续、方向易变等特点,地下火在所有火灾中对森林危害最大,特别是对落叶松、樟子松、云杉等的破坏更为严重。
Ground fire is an igniting phenomena that is difficult to control, and its mechanism is very complex. Daxing′an mountains forest region is the place that the ground fire occurs more often and regularly. Our study on ground fire of this zone in 2002 shows that plenty of combusibles near surface and undergound is the substance preconditions of forest ground fire, and the weather conditions promote the occurrence of ground fire. Especially in the condition with low precipitation, long time drought, surface temperature increasing, relative humidity depressing and combusibles dry, the ground fire is more easy to occur. Ground fire has spatiotemporal character. Ground fires occur mostly in primitive forest zone, such as conifer forest, broadleaf forest, conifer and broadleaf mixed forest. Ground fire often burns slowly, completely and for long, and it has the characteristics of high concealment, burning discontinuously, aspect shifting often. Ground fire is the fire that damages the forest most heavily, especially in Larix gmelini (Rupr.) Rupr., Pinus sylvestris L.var. mongolica Litv., Picea koraiensis Nakai. Ground fire as one complex phenomenon is difficult to be put out.
出处
《自然灾害学报》
CSCD
北大核心
2003年第4期62-67,共6页
Journal of Natural Disasters
基金
国家重点基础研究项目(2001CB409600)
国家"十五"科技攻关项目(2001BA510B09)
关键词
森林地下
腐殖质可燃物
泥炭可燃物
林火天气
forest ground fire
humus combusibles
turf combusibles
forest fire weather
