Characterization of Fuel Properties and Fire Spread Rates for Little Bluestem Grass
Characterization of Fuel Properties and Fire Spread Rates for Little Bluestem Grass
复制标题
小须芒草的燃料特性和火灾蔓延速率的表征
作者：
K. Overholt;J. Cabrera;A. Kurzawski;M. Koopersmith;O. Ezekoye
近几十年来，快速的城市扩张和人口分散增加了荒地-城市界面的规模，导致社区面临更高的野火风险和脆弱性。本文主要侧重于了解德克萨斯州常见的草燃火灾，并提高对草地和草原火焰传播问题中固有的物理和火灾动力学的理解。选择小蓝茎草（Schizachyrium scoparium）作为草地燃料，是因为它在德克萨斯州地区的普遍覆盖以及它与德克萨斯州草地火灾的相关性。本研究的方法依赖于一个框架来表征小蓝茎草的燃料特性，使用小型和中等规模的实验来更好地预测全面的火灾行为。建立了考虑燃料含水率的草类燃料的中尺度火焰传播数值模型，计算了小型蓝茎植物燃烧的质量与时间关系。采用基于物理的计算火灾模型——荒地-城市界面火灾动力学模拟器（WFDS），利用中小规模实验的结果为草地的野外数值模拟提供输入参数。进行敏感性分析以确定不同WFDS输入参数对火灾蔓延速度的影响。结果表明，燃料含水率对火灾蔓延速度的影响最为显著。
Rapid urban sprawl and population decentralization in recent decades have increased the size of the wildland-urban interface and resulted in higher community risk and vulnerability to wildfire. This paper primarily focuses on understanding grass-fueled fires common to Texas and improving the understanding of the physics and fire dynamics that are inherent in the grassland and prairie flame spread problem. Little bluestem (Schizachyrium scoparium) grass was chosen as the grassland fuel due to its prevalent coverage in the Texas area and its relevance to grassland fires in Texas. The methodology in this study relies on a framework to characterize fuel properties of little bluestem grass using small- and intermediate-scale experiments to better predict full-scale fire behavior. An intermediate-scale numerical flame spread model was developed for grass fuels that accounts for fuel moisture content to calculate the mass versus time of a burning little bluestem plant. The results of the small- and intermediate-scale experiments were used to develop input parameters for a field-scale numerical simulation of a grass field using a physics-based computational fire model, Wildland-urban interface Fire Dynamics Simulator (WFDS). A sensitivity analysis was performed to determine the effect of varying WFDS input parameters on the fire spread rate. The results indicate that the fuel moisture content had the most significant impact on the fire spread rate.