Exposure of the Canadian Wildland-Human Interface (WHI) and population to wildland fire, under current and future climate conditions

In Canada, recent fire seasons have demonstrated the threat of wildland fire in the Wildland-Human Interface (WHI) areas, where forest fuels intermingle with or abut housing, industry, and infrastructure. Although fire activity is expected to increase further in the coming decades as a result of climate change, no WHI-specific estimates of wildland fire exposure are currently available. This study combines spatial and demographic information sources to estimate the current and future wildland fire exposures, as reflected by fire return intervals (FRI) of WHI areas and populations across Canada. The WHI covers 17.3% of the forested area in Canada. Within the WHI, we found that 19.4% of the area currently experiences FRI ≤ 250 years but, by the end of the century, this could increase to 28.8% under RCP 2.6 and to 43.3% under RCP 8.5. Approximately 12.3% of the Canadian population currently live in the Wildland-Urban Interface (WUI), which includes 32.1% of the on-reserve First Nations population. Currently, 17.8% of the on-reserve WUI population is exposed to FRI ≤ 250 years, compared to only 4.7% of the remaining WUI population. By 2100, these proportions could reach 39.3% and 17.4% respectively, under the less optimistic climatic scenarios (RCP 8.5).The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author