The wildland-urban interface (WUI) is defined as a geographic area where human developments and flammable vegetation merge in a wildfire-prone environment. Losses due to wildfire have been rising in the past decade, attributed to changes in vegetation growth, fuel availability, and increased land developments in WUI. This paper studies the process of wildfire spread inside WUI communities. The fire spread rate within WUI communities is determined for nine wildfires that were ranked among the most destructive wildfires in North America. An improved quasi-empirical model that considers radiation and fire spotting as modes of fire spread inside a community is proposed. The new model is validated using the documented spread rates during the 2007 Witch and Guejito fires and the 2017 Tubbs fire. The proposed model is computationally efficient and can be used to quantify fire spread rate and the number of affected structures inside a community during a wildfire event.

荒地-城市界面 (WUI) 被定义为人类发展和易燃植被在易发生野火的环境中融合的地理区域。在过去十年中，野火造成的损失一直在上升，这归因于 WUI 中植被生长、燃料供应和土地开发增加的变化。本文研究了野火在 WUI 社区内蔓延的过程。WUI 社区内的火势蔓延速度是由九场被列为北美最具破坏性的野火的野火确定的。提出了一种改进的准经验模型，该模型将辐射和火灾点视为社区内火势蔓延的模式。使用 2007 年 Witch 和 Guejito 火灾以及 2017 年 Tubbs 火灾期间记录的传播率对新模型进行了验证。