基于模拟点烧不同加热时间和腐殖质粒径对森林地下火垂直燃烧的影响

目的森林地下火是一种缓慢、无焰、持续时间长的阴燃，对森林危害极大。大兴安岭地区是我国森林地下火频发区域，研究不同加热时间和腐殖质粒径对地下火垂直燃烧的影响，旨在为该地区森林地下火的预防、监测、扑救提供参考。方法以大兴安岭地区典型林型兴安落叶松林为研究对象，根据室内控制模拟点烧实验数据，使用SPSS进行双因素方差分析，O...

Effects of different heating times and humus particle sizes on vertical combustion of forest underground fire based on simulated spot burning

[Objective]The combustion of underground fire is a slow,flameless,long duration smoldering,which does great harm to forest.Daxing’anling region is a frequent area of forest underground fire in northeastern China.This paper aims to study the effects of different heating times and humus particle sizes on the vertical combustion of underground fires,aiming to provide a reference for the prevention,monitoring and suppression of underground fires in the area.[Method]Taking the typical forest type in the Daxing’an Mountains,i.e.Larix gmelinii forest as the research object,according to the indoor control simulation of scorching experiment data,SPSS was used to perform two-factor analysis of variance,and the Origin software was used to draw.The effects of three heating times and five humus particle sizes on the spreading speed and the highest temperature at different depths during the vertical combustion of underground fire were studied.[Result]During the vertical burning process of the forest underground fire,the temperature of the highest burning at a depth of 3 cm was only affected by the heating time and the difference was significant(P<0.05),but the effects of humus particle size on the difference were not significant(P>0.05).The highest temperature of combustion at a depth of 6 cm was affected by the heating time(P<0.05)and the particle size of humus(P<0.05).When the depth was greater than 6 cm,the maximum combustion temperature was only affected by the humus particle size and the difference was significant(P<0.05).The spread rate during the vertical combustion of forest underground fires was only affected by the humus particle size.There were significant differences between the spreading speeds(P<0.05).[Conclusion]The highest temperature of underground forest fires burning at 3 cm and 6 cm depth rises with the increase of heating time,and the burning temperature is the highest when heated for 2 h.When the vertical combustion depth is 9-21 cm,the humus particle size is 40 mesh,the burning temperature is the highest.Among the effects of humus particle size on the spread speed of forest underground fires,the spread speed of humus particle size 20 mesh is the fastest;when the humus particle size is 60 mesh,it is the criticality in the process of underground fire combustion.The highest combustion temperature and spread speed are lower.