Firebrands are known to be able to ignite not only vegetation but also various structures found in wildland-urban interface (WUI) area. Especially, firebrands located close to each other on a combustible substrate increase the likelihood of ignition and the subsequent fire. To elucidate the ignition mechanism of firebrands, experiments are performed using a 3 by 3 square array of flaming firebrands deposited on a 6.35 mm thick birch plywood. The spacing of the firebrand is varied in each experiment, ranging from 10 to 30 mm. The deposited mass of firebrands lies between 13 and 15 g. Ambient wind is imposed parallel to the plywood surface to investigate its effect on the ignition and the subsequent flame spread over the fuel. Three different wind speeds 0, 0.5, and 0.75 m/s are tested. During the experiments, mass loss of the plywood and the deposited firebrands is recorded. Video cameras are used to monitor the burning process. An infrared camera is also used to monitor the temperature of the firebrands and the plywood. The experiment results indicate that the firebrands with the spacing greater than 20 mm are able to burn only the surface of the plywood until the firebrands burn out. Whenmore »
Simulating Potential Impacts of Fuel Treatments on Fire Behavior and Evacuation Time of the 2018 Camp Fire in Northern California
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 more »
- Award ID(s):
- 1664173
- Publication Date:
- NSF-PAR ID:
- 10347208
- Journal Name:
- Fire
- Volume:
- 5
- Issue:
- 2
- Page Range or eLocation-ID:
- 37
- ISSN:
- 2571-6255
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Publisher's Version of Record
- https://doi.org/10.3390/fire5020037
