森林火灾对泥石流孕灾环境及成灾机制的影响分析  

Analysis on the influence of forest fire on the disaster environment and disaster mechanism of debris flow

作　　者：罗冠枝 罗敏玄 陈全明 方琼 LUO Guanzhi;LUO Mingxuan;CHEN Quanming;FANG Qiong(Changsha Natural Resources Comprehensive Survey Center,China Geological Survey,Changsha 410600,Hunan,China;Center for Natural Resources Affairs of Hunan Province,Changsha 410004,Hunan,China)

机构地区：[1]中国地质调查局长沙自然资源综合调查中心,湖南长沙410600 [2]湖南省自然资源事务中心,湖南长沙410004

出　　处：《矿产勘查》2024年第8期1517-1523,共7页Mineral Exploration

基　　金：湖南省自然资源厅科研项目(2020B02);中国地质调查局项目“大别山区东段生态修复综合调查(DD20242416)”联合资助。

摘　　要：火后泥石流是最危险的森林火灾次生灾害之一,为了探讨森林火灾对泥石流孕灾环境及成灾机制的影响,本文以湖南新田县过火区域为研究对象,利用遥感解译、野外实地调查、室内实验等方法,开展火后泥石流孕灾因子及成灾机制研究。研究结果表明,森林火灾对岩土体、植被和物源产生重要影响,因岩土体性质和植被烧毁的影响,提高了坡面地表径流和坡面侵蚀,降低了泥石流启动降雨阈值,形成初次以灰烬层为主的泥石流。这与常规泥石流的特点和成灾机制有所不同,可为火后泥石流灾害防治与风险评价提供重要参考和技术支撑。Debris flow after fire is one of the most dangerous secondary disasters of forest fire.In order to explore the impact of forest fire on the disaster environment and disaster mechanism of debris flow,the fire area in Xintian County of Hunan was taken as the research object,and the disaster factors and disaster mechanism of debris flow after fire were studied by using remote sensing interpretation,field investigation and laboratory experi⁃ment.The results show that forest fires have an important impact on rock and soil mass,vegetation and provenance.Due to the impact of rock and soil mass properties and vegetation burning,the slope surface runoff and slope erosion are increased,the threshold value of debris flow starting rainfall is reduced,and the debris flow mainly consisting of ash layer is formed for the first time.This is different from the characteristics and disaster mechanism of conventional debris flow,which can provide important reference and technical support for post fire debris flow disaster prevention and risk assessment.

关 键 词：火后泥石流 森林火灾 孕灾环境 成灾机制 灾害防治 

分 类 号：P642.23[天文地球—工程地质学]