Simulating Potential Impacts of Fuel Treatments on Fire Behavior and Evacuation Time of the 2018 Camp Fire in Northern California

Daisuke Seto,Callum Thompson,Jacob Gellman,Charles Jones,Leila M V Carvalho,Kristofer Daum,Kevin Varga,Andrew J Plantinga,Anna T Trugman

doi:10.3390/fire5020037

Abstract

Fuel break effectiveness in wildland-urban interface (WUI) is not well understood during downslope wind-driven fires even though various fuel treatments are conducted across the western United States. The aim of this paper is to examine the efficacy of WUI fuel breaks under the influence of strong winds and dry fuels, using the 2018 Camp Fire as a case study. The operational fire growth model Prometheus was used to show: (1) downstream impacts of 200 m and 400 m wide WUI fuel breaks on fire behavior and evacuation time gain; (2) how the downstream fire behavior was affected by the width and fuel conditions of the WUI fuel breaks; and (3) the impacts of background wind speeds on the efficacy of WUI fuel breaks. Our results indicate that WUI fuel breaks may slow wildfire spread rates by dispersing the primary advancing fire front into multiple fronts of lower intensity on the downstream edge of the fuel break. However, fuel break width mattered. We found that the lateral fire spread and burned area were reduced downstream of the 400 m wide WUI fuel break more effectively than the 200 m fuel break. Further sensitivity tests showed that wind speed at the time of ignition influenced fire behavior and efficacy of management interventions.

Highlights

Wildfire behavior regimes can be broadly characterized as either fuel-dominated or wind-dominated
This study investigated the effectiveness of wildland urban interface (WUI) fuel breaks on downslope winddominated fire behavior, including intensity and rate.breaks
The model simulations presented in this study indicate that WUI fuel breaks would have afforded more evacuation time for the town of Paradise

Summary

Introduction

Wildfire behavior regimes can be broadly characterized as either fuel-dominated or wind-dominated. Fuel-dominated fires, known as plume or convection-dominated fires [2–5], are predominantly controlled by anomalously high fuel loads and are common in central and northern California conifer forests during peak lightning season (June–July), coinciding with high air temperatures and low precipitation [6]. These fires tend to occur in low populated regions. Wind-dominated fires are mostly caused by ignitions from humans or infrastructure failure, such as downed power lines during extreme downslope wind events These are typically dry, warm, and gusty downslope windstorms occurring on the lee-side of mountain ranges and often have geographically distinct names, such as the North, Diablo, Sundowner, and Santa Ana winds in California [7]. The potential for significant loss of life and property increases because fire suppression efforts have very limited success

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