Catastrophic wildfires are often a result of dynamic fire behaviours. They can cause rapid escalation of fire behaviour, increasing the danger to ground-based emergency personnel. To date, few studies have characterised merging fire behaviours outside the laboratory. The aim of this study was to develop a simple, fast and accurate method to track fire front propagation using emerging technologies to quantify merging fire behaviour at the field scale. Medium-scale field experiments were conducted during April 2019 on harvested wheat fields in western Victoria, Australia. An unmanned aerial vehicle was used to capture high-definition video imagery of fire propagation. Twenty-one junction and five inward parallel fire fronts were identified during the experiments. The rate of spread (ROS) of junction fire fronts was found to be at least 60% higher than head fire fronts. Thirty-eight per cent of junction fire fronts had increased ROS at the final stage of the merging process. Furthermore, the angle between two junction fire fronts did not change significantly in time for initial angles of 4–14°. All these results contrast with previous published work. Further investigation is required to explain the results as the relationship between fuel load, wind speed and scale is not known.

中文翻译：

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使用无人机技术量化合并火灾行为现象

灾难性的野火通常是动态火灾行为的结果。它们会导致火灾行为迅速升级，增加对地面应急人员的危险。迄今为止，很少有研究描述实验室外的合并火灾行为。本研究的目的是开发一种简单、快速和准确的方法来跟踪火锋传播，使用新兴技术来量化现场规模的合并火灾行为。2019 年 4 月，在澳大利亚维多利亚州西部收获的麦田上进行了中等规模的田间试验。一架无人机用于捕捉火势蔓延的高清视频图像。在实验过程中确定了 21 个交汇点和 5 个向内平行的火锋。发现交界火线的蔓延率 (ROS) 至少比头部火线高 60%。在合并过程的最后阶段，38% 的交界火线增加了 ROS。此外，对于 4-14° 的初始角度，两个交界火锋之间的角度在时间上没有显着变化。所有这些结果都与之前发表的工作形成对比。由于燃料负荷、风速和规模之间的关系尚不清楚，因此需要进一步调查来解释结果。