Wildfire evacuation patterns and syndromes across Canada's forested regions

Abstract

Human exposure to wildfire is increasing in many regions globally—a trend likely to continue as climate change drives increases in wildfire activity and human populations continue to expand into fire‐prone landscapes. In Canada, this trend is reflected by a steady increase in the annual number of wildfire evacuations since the 1980s. Evacuations can be costly and cause severe stress, even when homes remain undamaged. Because many factors driving community vulnerability are likely correlated, classifying at‐risk communities into groups whose members share common drivers of wildfire vulnerability will be helpful in identifying the key wildfire evacuation “syndromes” that are repeated in different parts of the landscape. Understanding these syndromes will aid in anticipating and mitigating the effects of future fire exposure. Here, we classify the populated places across Canada's forested regions into 19 groups using variables describing their potential vulnerability to wildfire, including the surrounding land cover, land use and infrastructure, and the local fire regime. Then, we evaluate the utility of these groups by comparing actual wildfire exposure among the groups using a unique dataset of 1043 wildfire evacuations from 1980 to 2019. We identified three main evacuation syndromes that represent 79% of all evacuations and are distinct in their geographic distribution, the characteristics of the fires that drove the evacuations, the communities exposed, and the likely mode of evacuation. In remote areas dominated by conifer forest, evacuations were driven primarily by lightning‐ignited fires in the summer. Exposed communities typically lacked access to the road network, making it important to plan for evacuation by air. In less remote mixedwood forest areas, evacuations were driven largely by human‐ignited fires in the spring, and most communities had access to major roads. In interior British Columbia, evacuations were mainly in the summer and driven by both lightning‐ and human‐ignited fires. These areas experienced the greatest increase in evacuation frequency over the last two decades, reflecting the local trend of increasing wildfire activity. These differences highlight how the major risk factors vary spatially across the forested regions and temporally over the fire season—knowledge that will facilitate more effective planning for future fire seasons.

Biogeographic patterns of daily wildfire spread and extremes across North America

“…While population density is fairly low, this ecoregion has many rural, remote, and dispersed communities that often include First Nations Indigenous people who are disproportionately impacted by these extreme events (Davies et al, 2018;McGee, 2021). Furthermore, evacuations are complicated by having few or indirect roads to these remote communities (Tepley et al, 2022). Human impacts due to fire duration are also important to consider for those communities that are experiencing long evacuations (Stidham et al, 2011) and the strain on fire fighters who have extended deployments on these long-duration incidents (Vincent et al, 2016;Jeklin et al, 2020).…”

Canada Under Fire – Drivers and Impacts of the Record-Breaking 2023 Wildfire Season

“…Evacuation data for Canada for 1980-2023 were obtained by request from the Canadian Wildland Fire Evacuation Database (Natural Resources Canada, 2023a). This data is compiled using an exhaustive search of media reports and quality control measures as described by Tepley et al (2022). Evacuation data from 2023 are provisional and are subject to updates as evacuation numbers are confirmed.…”

Wildland fire evacuations in Canada from 1980 to 2021

“…Beverly and Bothwell (2011) also presented the data sources and approach used in data collection of the initial version of the CWFED. Additionally, a recent study on wildland fire evacuation in Canada's forested regions used the CWFED to examine wildland fire evacuation patterns and the characteristics of fires that necessitated evacuation (Tepley et al 2022). A growing literature on a variety of topics in wildland fire evacuation research has been investigated in Canada, including intended behavioural responses (Cote and McGee 2014), evacuation experiences (Scharbach and Waldram 2016;Downe et al 2018;Asfaw et al 2019;Betancur Vesga 2019;Christianson et al 2019;Mamuji and Rozdilsky 2019;McGee 2019;McGee et al 2019;Mottershead et al 2020;Drolet et al 2021;McGee et al 2021), evacuation reconstructions (Woo et al 2017), evacuation modelling (Folk 2019Wahlqvist et al 2021;Yerushalmi et al 2022), charitable response (Boulianne et al 2018;Yumagulova et al 2019), children (Kulig et al 2018;DeYoung et al 2018), and recovery (Pujadas Botey and Kulig 2014;Shepard et al 2017;Montesanti et al 2021;Lalani et al 2021).…”