The Impact of Fuel Treatments on Wildfire Behavior in North American Boreal Fuels: A Simulation Study Using FIRETEC

Ginny Marshall,Rodman Linn,Dan Thompson,Kerry Anderson,Dave Schroeder,Brian Simpson

doi:10.3390/fire3020018

Ginny Marshall, Rodman Linn + Show 4 more

Open Access

https://doi.org/10.3390/fire3020018

Copy DOI

Abstract

Current methods of predicting fire spread in Canadian forests are suited to large wildfires that spread through natural forests. Recently, the use of mechanical and thinning treatments of forests in the wildland-urban interface of Canada has increased. To assist in community wildfire protection planning in forests not covered by existing operational fire spread models, we use FIRETEC to simulate fire spread in lowland black spruce fuel structures, the most common tree stand in Canada. The simulated treatments included the mechanical mulching of strips, and larger, irregularly shaped areas. In all cases, the removal of fuel by mulch strips broke up the fuels, but also caused wind speed increases, so little decrease in fire spread rate was modelled. For large irregular clearings, the fire spread slowly through the mulched wood chips, and large decreases in fire spread and intensity were simulated. Furthermore, some treatments in the black spruce forest were found to be effective in decreasing the distance and/or density of firebrands. The simulations conducted can be used alongside experimental fires and documented wildfires to examine the effectiveness of differing fuel treatment options to alter multiple components of fire behavior.

Highlights

The use of mechanical and thinning treatments for wildfire mitigation in the wildland-urban interface of Canada has increased; current methods of predicting fire behavior in Canadian forests are suited to large wildfires that spread through natural forests
American fire behavior prediction systems, the National Fire Danger rating system (NFDRS) in the USA and the Canadian Forest Fire Danger Rating system (CFFDRS) in Canada [1,2], generally struggle at two scales: (1) large (102 –104 ) ha, plume or column driven wildfire events with time scales on the order of hours, where models based on small, wind-driven experimental fires or laboratory surface fires fail; (2) heterogeneous fuel structures, where models built upon homogenous fuels at the 1–5 ha scale suffer from an inability to represent changes in fuels structure at the scale of meters
In the realm of disturbances or forest thinning treatments that structurally alter the forest, it would be resource intensive to attempt to empirically characterize the response of wildfire spread and intensity on all manner of thinning treatments and forest modification across a range of fire conditions; rather, the strategy has been instead to build wildfire spread models from basic principles using a physics-based approach. One such implementation of a physics-based wildfire spread model that accounts for energy and mass movement at the meter scale is FIRETEC [5], which has been used successfully for over a decade to simulate wildfire behavior, primarily in dry conifer forest, shrublands, and grasslands

Summary

Introduction

The use of mechanical and thinning treatments for wildfire mitigation in the wildland-urban interface of Canada has increased; current methods of predicting fire behavior in Canadian forests are suited to large wildfires that spread through natural forests. In the realm of disturbances or forest thinning treatments that structurally alter the forest, it would be resource intensive to attempt to empirically characterize the response of wildfire spread and intensity on all manner of thinning treatments and forest modification across a range of fire conditions; rather, the strategy has been instead to build wildfire spread models from basic principles using a physics-based approach One such implementation of a physics-based wildfire spread model that accounts for energy and mass movement at the meter scale is FIRETEC [5], which has been used successfully for over a decade to simulate wildfire behavior, primarily in dry conifer forest, shrublands, and grasslands.

Methods

Results

Conclusion