Zhang Ji-Li, Liu Bo-Fei, Chu Teng-Fei, Di Xue-Ying, Jin Sen
College of Forestry, Northeast Forestry University, Harbin, China.
Ying Yong Sheng Tai Xue Bao. 2012 Jun;23(6):1495-502.
A laboratory burning experiment was conducted to measure the fire spread speed, residual time, reaction intensity, fireline intensity, and flame length of the ground surface fuels collected from a Korean pine (Pinus koraiensis) and Mongolian oak (Quercus mongolica) mixed stand in Maoer Mountains of Northeast China under the conditions of no wind, zero slope, and different moisture content, load, and mixture ratio of the fuels. The results measured were compared with those predicted by the extended Rothermel model to test the performance of the model, especially for the effects of two different weighting methods on the fire behavior modeling of the mixed fuels. With the prediction of the model, the mean absolute errors of the fire spread speed and reaction intensity of the fuels were 0.04 m X min(-1) and 77 kW X m(-2), their mean relative errors were 16% and 22%, while the mean absolute errors of residual time, fireline intensity and flame length were 15.5 s, 17.3 kW X m(-1), and 9.7 cm, and their mean relative errors were 55.5%, 48.7%, and 24%, respectively, indicating that the predicted values of residual time, fireline intensity, and flame length were lower than the observed ones. These errors could be regarded as the lower limits for the application of the extended Rothermel model in predicting the fire behavior of similar fuel types, and provide valuable information for using the model to predict the fire behavior under the similar field conditions. As a whole, the two different weighting methods did not show significant difference in predicting the fire behavior of the mixed fuels by extended Rothermel model. When the proportion of Korean pine fuels was lower, the predicted values of spread speed and reaction intensity obtained by surface area weighting method and those of fireline intensity and flame length obtained by load weighting method were higher; when the proportion of Korean pine needles was higher, the contrary results were obtained.
在中国东北帽儿山的红松（Pinus koraiensis）和蒙古栎（Quercus mongolica）混交林中，采集了地表可燃物，在无风、零坡度以及不同含水率、载量和混合比例条件下，进行了实验室燃烧实验，以测量其火灾蔓延速度、持续时间、反应强度、火线强度和火焰长度。将测量结果与扩展的罗瑟梅尔模型预测值进行比较，以检验该模型的性能，特别是两种不同加权方法对混合可燃物火灾行为建模的影响。通过该模型预测，可燃物的火灾蔓延速度和反应强度的平均绝对误差分别为0.04 m·min⁻¹和77 kW·m⁻²，平均相对误差分别为16%和22%；而持续时间、火线强度和火焰长度的平均绝对误差分别为15.5 s、17.3 kW·m⁻¹和9.7 cm，平均相对误差分别为55.5%、48.7%和24%，表明持续时间、火线强度和火焰长度的预测值低于观测值。这些误差可视为扩展的罗瑟梅尔模型在预测类似可燃物类型火灾行为时的下限，并为利用该模型预测类似野外条件下的火灾行为提供有价值的信息。总体而言，两种不同加权方法在扩展的罗瑟梅尔模型预测混合可燃物火灾行为方面未显示出显著差异。当红松可燃物比例较低时，采用表面积加权法得到的蔓延速度和反应强度预测值以及采用载量加权法得到的火线强度和火焰长度预测值较高；当红松针叶比例较高时，得到相反的结果。
