Framework for spatial incident-level wildfire risk modelling to residential structures at the wildland urban interface

Abstract

Understanding wildfire impacts on structures in wildland urban interface (WUI) communities is fundamental for emergency response and mitigation planning to reduce potential social and economic losses. The magnitude of structures loss determines the direct economic costs for re-building, indirect economic losses due to evacuation and disruption of economic activities as well as shelter needs. This paper presents a framework for the development and implementation of incident-level wildfire impact assessment of WUI residential structures including the following successive components: hazard, inventory, exposure, and impact. The hazard model generates spatial and temporal distribution of fire intensity for wildfire event scenarios; the inventory model provides spatial pattern of exposed structures; the exposure model estimates the fire intensity at WUI locations; whereas the impact model evaluates the structures loss by applying newly developed empirical response functions represented as the relationship between fire intensity, distance from forest edge and expected proportion of burned structures. A case study application of the proposed framework is presented for loss assessment of structures in a WUI community of the northern boreal forest of Canada. The proposed framework is particularly useful to the public safety community for conducting what-if scenarios of wildfire impact in support of emergency and mitigation planning.