烟头点燃蒙古栎落叶床层的概率

Burning Probability of Fuelbed Composed of Mongolian Oak Leaf Ignited by Cigarette ends

以蒙古栎凋落叶片为实验材料,在室内构建不同含水率、风速及压缩比的可燃物床层,用烟头对蒙古栎落叶床层进行了900余次点燃燃烧试验,记录点燃概率,并进行统计分析。结果表明:风速对点燃概率有很大影响,当风速<2 m·s-1时,不论蒙古栎落叶的含水率与压缩比如何改变,烟头都不能点燃蒙古栎落叶;当风速≥2 m·s-1时,可燃物能够点燃,但风速对点燃概率无显著作用。含水率、床层压缩比对燃烧概率有极显著作用,3个因子间的交互作用对燃烧概率也有极显著作用。当可燃物含水率超过10%时,无论有风无风,烟头都难以点燃蒙古栎凋落叶片。用Logistic回归拟合得到含水率、风速、压缩比对烟头点燃蒙古栎落叶的概率模型,模型预报的准确率在90%左右,误报率不超过40%。

Fuelbeds composed of Mongolian oak leave were constructed with varied fuel moisture contents and packing ratios .Over 900 ignition experiments were conducted by dropping cigarette ends on the fuelbeds to test burning probability of the fuels under varied wind speeds .The wind speed significantly influenced burning probability of the fuelbed .No fuelbed was igni-ted when wind speed was lower than 2 m· s-1 regardless of fuelbed packing ratio and moisture content .Fuebed was ignited when wind speed was higher than 2 m· s-1 , but the wind speed makes no significant differences on burning probability . Fuel moisture content , packing ration and their interaction with wind speed affected burning probability .No burning oc-curred when fuel moisture content was higher than 10%.A logistic model was established for predicting burning probability by using these variables with accuracy of 90%.