平地无风条件下红松针叶床层林火蔓延的影响因子分析及模拟

Influence Factors on Fire Spread Across Fuel Beds of Korean Pine Needles Under No-wind and Zero-slope Conditions and Modeling of Fire Behavior

以红松(Pinus koraiensis)人工林的针叶为材料,在实验室内,根据黑龙江省帽儿山地区同类可燃物的野外条件,构建了不同载量、高度和含水率的可燃物床层,共进行了100次的平地无风条件下的点烧试验,结果表明,平地无风条件下红松针叶床层的林火蔓延速率不超过0.4 m.min-1。红松针叶含水率、床层高度和压缩比对林火蔓延速率具有显著的影响。其中,含水率对林火蔓延速率的影响与可燃物床层的高度、载量等无显著关系,而可燃物床层高度和压缩比对林火蔓延的影响可能受可燃物床层特征的影响,需进一步研究确定。床层载量对红松针叶床层的林火蔓延速率影响不大。以可燃物含水率和床层高度为预测因子的林火蔓延速率线性预测模型,能够解释85%的林火蔓延速率变差,模型的平均绝对误差为0.03 m.min-1,平均相对误差不超过13%。

Fuel beds composed of pine needles collected from Korean pine plantations were constructed according to various fuel moisture,loading and depth.A total of 100 experimental fires with these fuel beds were burned inside laboratory under no wind and zero-slope conditions.Results indicate that the rates of fire spread across fuel beds of Korean pine needles are slower than 0.4 m·min-1.Fuel moisture,fuel bed depth and packing ratio significantly influence fire spread.The effect of fuel moisture on fire spread is not affected by fuel bed depth and loading,while those of fuel bed depth and packing ratio on rate of fire spread might be influenced by other fuel bed characteristics,which still needs to be confirmed.Loading of fuel beds has little influence on the rate of fire spread across fuel beds.A linear spread model was established using fuel moisture and fuel bed depth as predictive variables.The model could account for 85 percent of the variance in rate of fire spread,with mean absolute error of 0.03 m·min-1 and mean relative error less than 13 percent.