高级检索

    基于Rothermel模型的红松人工林地表可燃物蔓延速率及参数修正

    Spread rate and parameter correction of surface fuel in Pinus koraiensis plantation based on Rothermel model

    • 摘要:
        目的  该研究以室内模拟野外真实条件下的燃烧试验为手段,测定不同坡度和含水率条件下东北红松人工林地表可燃物蔓延速率,与基于Rothermel模型预测蔓延速率对比,并对Rothermel模型进行修正,以提高Rothermel模型预测红松人工林地表可燃物燃烧蔓延速率的适用性。
        方法  以红松人工林地表可燃物为试验材料,在实验室内构建不同含水率和坡度的可燃物床层结构,平地无风条件下进行30次点烧试验,5°、10°、15°和20°条件下分别进行15次点烧试验。根据热电偶记录的温度时间数据及位置数据计算燃烧蔓延速率,在平地条件下对Rothermel模型中相关可燃物的参数进行拟合,得到最优模型,在此基础上对Rothermel模型坡度参数修正。
        结果  在各试验条件下,红松人工林地表火蔓延速率最大值为0.631 m/min,最小值为0.114 m/min;直接使用Rothermel模型预测0° ~ 20°坡度条件下红松人工林地表火燃烧蔓延速率平均绝对误差为0.059 m/min,范围为0.003 ~ 0.241 m/min,平均相对误差为27.4%,范围为2.4% ~ 152.6%;在使用平地无风条件下点烧试验数据重新修正Rothermel模型的可燃物特征参数βop的基础上,基于5° ~ 20°条件下点烧试验数据修正坡度参数,修正参数后的Rothermel模型平均绝对误差平均值降低了0.024 m/min,为0.035 m/min,范围为0.003 ~ 0.102 m/min,平均相对误差降低了10.4%,为17.0%,范围为1.8% ~ 65.5%;修正参数后模型预测值与实测值的R2为0.913 5。
        结论  在0° ~ 20°坡度条件下不能直接使用Rothermel模型对红松人工林地表可燃物燃烧蔓延速率进行预测,需要对模型中的可燃物特征参数和坡度参数进行修正,拟合参数后模型预测误差显著降低,预测精度显著提升,可以对我国0° ~ 20°坡度条件下红松人工林地表火蔓延速率进行预测。

       

      Abstract:
        Objective  Based on laboratory simulation burning experiment, this paper aims to measure the spread rate of surface fuel in Pinus koraiensis plantation under different slopes and water contents, compared with the spread rate calculated by Rothermel model, and modify the parameter of Rothermel model to increase the applicability in Korean pine plantation.
        Method  Taking surface fuel of Pinus koraiensis plantation as experimental materials, according to the field conditions of sample plots, the fuel bed was established with different water contents and slopes. 30 times burning experiments were conducted under no slope and no wind conditions, 5°, 10°, 15° and 20° each for 15 times, in a total of 90 time experiments. The calculation of spread rate was based on thermocouple, its location data, and fit the parameters of Rothermel model in no slope and no wind conditions to obtain the optimal model, and correct slope coefficient of Rothermel model.
        Result  In all experiments, the maximum spread rate was 0.631 m/min, and the minimum spread rate was 0.114 m/min. The mean average absolute error was 0.059 m/min, and the range was 0.003−0.241 m/min, and the average relative error was 27.4%, which was calculated by Rothermel model, and the range was 2.40%−152.6%. On the basis of re-correcting the fuel characteristic parameter βop of the Rothermel model with the burning test data under flat ground and no wind, the slope correction parameters were corrected based on the burning test data under the conditions of 5°−20°, and the mean value of average absolute error for Rothermel model after the correction had reduced by 0.024 m/min, which was 0.035 m/min, the range was 0.003−0.102 m/min, and the average relative error had reduced by 10.44% , being 17.0%, and the range was 1.8%−65.5%; R2 was 0.913 5 between measured spread rate and predicted value after parameter correction.
        Conclusion  The Rothermel model cannot be directly used to predict the spread rate of surface fuel in Pinus koraiensis plantation under the slope of 0°−20°, the fuel characteristic parameter and slope coefficient parameter need to be corrected. After parameter correction, the prediction error is significantly reduced, and the prediction accuracy is significantly improved. Then it is possible to predict the surface fuel spread rate in Pinus koraiensis plantation under low slope conditions in China.

       

    /

    返回文章
    返回