森林地下火是发生在腐殖质层和泥炭层的一种森林火灾，不仅毁坏植被根部造成致命损伤，还会破坏土壤结构造成地面坍塌，同时释放的温室气体要远大于有焰火灾。地下火具有隐蔽性强、燃烧时间长等特点。地下火难判、难打、难清、难守一直困扰着森林消防人员。大兴安岭地区林下可燃物丰富且腐殖质层厚度可达半米以上，是我国地下火的频发区域。本项目以大兴安岭地区为研究区，通过历史森林火灾资料和遥感数据构建地下火空间数据库，分析地下火发生规律，建立地下火预警模型；通过野外调查、室内外模拟点烧实验、控制实验等手段量化不同环境下地下火行为参数，建立地下火行为模型；根据地表/地下可燃物特性、火行为参数，研究地表火发生后转变为地下火的概率和条件，探索地下火发生后向地表火转变的过程，最终探究地表火和地下火相互转变的发生机理。本成果旨在为地下火的预防、监测和扑救提供技术支撑，并对降低扑火人员伤亡和保护森林资源具有重要现实意义。

Forest ground fire includes humus fire and peat fire, which will case critical damage to the plant root system and surface collapse because of soil structure. Smouldering combustion in humus and peat produces a higher proportion of greenhouse gases than flaming fires in vegetation. Forest ground fire is a kind of persistent combustion and hard to be detected. Forest ground fire perplexes firefight work in monitoring, extinguishment, mop-up and resurgence all the time. . Forest ground fire is frequent in Daxing’anling region due to its abundant understory fuel and more than half-meter thick humus layer, so we will choose Daxing’anling region as our study area. We will establish the spatial database of forest ground fire through historical forest fire data and remote sensing data, explore the regularity and construct early warning model of forest ground fire. Then we will construct fire behavior model through field study, simulated combustion experiments and controlled experiments. In the end, we will research the transition and transformation mechanism between smouldering and flaming combustion by fuel characteristics and fire behaviour. The research production of this project can provide technology support in prevention, monitoring and suppression of forest ground fire, and it is important to reduce firefighting casualties and protect forest resources.