Fig. 3
From: Twenty-first century California, USA, wildfires: fuel-dominated vs. wind-dominated fires
(a) 1964 Hanly Fire perimeter (purple line) with low and high density housing distribution, and (b) 2017 Tubbs Fire perimeter (purple line) with housing distribution. Housing density data were spatially distributed and mapped using methods described in Hammer et al. 2004 and Syphard et al. 2009. Within the attributes of partial block groups, all areas designated as having housing density between 6.17 to 49 houses per square kilometer were mapped as low density, with 6.17 corresponding to the minimum housing density cutoff for low-density wildland–urban interface (WUI; Radeloff et al. 2005). The threshold of ≥50 houses per square kilometer corresponds to the same housing density as used for areas defined as medium or high density WUI. Some have downplayed the similarity of the Hanly and Tubbs fires because the former lasted three days and the Tubbs Fire much shorter. However, the Hanly Fire was nearly double the size of the Tubbs Fire and, in the last day of both fires, there was a rapid run from Calistoga to Santa Rosa, driven by North Winds, suggesting very similar fire behavior. Inset illustrates location in California