Fire Behavior
Webinar recording.
This webinar will provide an overview of the major changes in CO-WRA, including modification of Scott and Burgan (2005) standard fire behavior fuel models to better reflect fuel types in Colorado, incorporating LiDAR to produce higher spatial resolution data products, and advanced wildland-urban interface risk analysis. Presenters will explain how these datasets and information can be used to: (1) increase public awareness about wildfire risk; (2) support wildfire risk reduction efforts, decision-making, and research from state to local scales; (3) identify high priority areas; (4) assist in the development of Community Wildfire Protection Plans (CWPPs) and other hazard mitigation plans; and (5) complement forest stewardship and forest management plans.
After a brief review, presenters will explore discussions and questions from participants to address technical issues.
View synthesis.
This paper provides a synthesis of the key laboratory- and field-based observational studies focused on wildland fire and atmospheric turbulence connections that have been conducted from the early 1900s through 2021. Included in the synthesis are reports of anecdotal turbulence observations, direct measurements of ambient and fire-induced turbulent flow in laboratory and wildland environments, and remote sensing measurements of fire-induced turbulent plume dynamics. Although considerable progress has been made in advancing our understanding of the connections between atmospheric turbulence and wildland fire behavior and smoke dispersion, gaps in that understanding still exist and are discussed to conclude the synthesis.
View article.
Vegetation and substrate burn severity was characterized as moderate across the study site and did not differ among treatments. Contrasting with higher pre-fire shrub density in the mastication + burning treatment, 2-year post-fire live shrub density did not differ among treatments. Higher pre-fire fine woody fuel loading in the mastication treatment did not correspond to post-fire fuel loading among treatments, while the hand thinned treatment was the only treatment where fine fuel loading was not significantly reduced post-fire. Total plant species richness increased in all treatment types following wildfire, largely driven by an increase in exotic species. Native cover decreased, and exotic cover increased in oak and chaparral types, but greater exotic species cover in the mastication + burning treatment in chaparral was maintained following wildfire.
View article.
Focus on wind changes and mid-tropospheric properties may be counterproductive or distracting when one is concerned about major growth events on very large fires.
View article.
Our study found that fire perimeter source and fireline buffer width had the largest impact on quantified fireline effectiveness metrics. Misclassification of firelines produced dramatic erroneous results which artificially increased the effectiveness and decreased suppression effort. High-severity fires were shown to be less effective across all fireline types and required higher suppression than most low- and moderate-severity fires.
View article.
This review summarises a growing body of evidence indicating that greater use of in situ, remotely sensed, and modelled soil moisture information in fire danger rating systems could lead to better estimates of dynamic live and dead herbaceous fuel loads, more accurate live and dead fuel moisture predictions, earlier warning of wildfire danger, and better forecasts of wildfire occurrence and size. Potential uses of soil moisture information in existing wildfire danger rating systems include (1) as a supplement or replacement for drought indices, (2) for live and (3) dead fuel moisture modelling, (4) for estimating herbaceous fuel curing, and (5) for estimating fuel loads. We identify key remaining research questions and note the logistical challenge of convincing wildfire professionals of the importance of soil moisture compared with more familiar wildfire danger metrics. While obstacles remain, the path forward is clear. Soil moisture information can and should be used to improve fire danger rating systems and contribute to more effective fire management for the protection of communities and ecosystems worldwide.
View story map.
But over the past few decades, wildfires have worsened by almost every metric. It’s impossible to ignore this new consequence of environmental change. Fires are getting larger, more severe, more destructive and dangerous, and eliminating entire patches of forests, grasslands, and shrublands.
The combination of changing climate, extreme weather, land use, aggressive fire suppression policies, and wildland urban interface expansion have contributed to altered fire behavior regimes. And all of these past and current factors are converging in a big way in the western U.S. Today’s megafires pose an increasing threat to human health, infrastructure, natural resources, and ecosystem resilience.
View synthesis.
Here, we synthesized literature and conducted a survey of forest and fire managers to assess current understanding of how fire interacts with aspen stands, as well as to examine possible factors that influence fire occurrence, behavior, and severity in aspen communities. We found evidence that the presence of aspen reduces fire occurrence, fire behavior, and fire severity, but this effect is dependent on many factors, including the percentage of aspen vs conifers in the overstory, load and type of understory fuels, weather, and season. We did not find any quantitative management guidelines on how to create, maintain, or use aspen stands to reduce fire risk. The large gap between “common knowledge” and empirical evidence regarding aspen’s ability to inhibit fire requires further research.
Webinar recording.
The fourth webinar of the Forest Service’s Research and Development SCIENCEx FIRE week.
Modeling Risks and Tradeoffs
Wildland Fire Behavior and Ignition | Greg Dillon
Juggling Risks and Tradeoffs Toward a More Resilient Future: The Known, Unknown, Unknowable, and Unpleasant | Pat Manley & Nick Povak
Southern Forest Outlook: Fire in a Changing Landscape | Nick Gould
Webinar recording.
The third webinar of the Forest Service’s Research and Development SCIENCEx FIRE week.
Fire Behavior
Wildland Fire Behavior and Ignition | Sara McAllister
3D Time-Dependent Fire Behavior Models: What They Do and the Need for Observational Datasets | Ruddy Mell
Fire Behavior Assessment Team (FBAT) and Wildfire Monitoring | Matt Dickinson