Fire Behavior
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The Advanced Fire Environment Learning Unit (AFELU) hosts three speakers to talk about Predictive Services comparison tools, predicting fire behavior in Alaska, and smoke tools. The target audience is anyone interested in fire behavior, fire weather, or fire prediction.
Read the review.
This review paper presents simulations and experiments of hypothetical prescribed burns with a suite of selected fire behavior and smoke models and identifies major issues for model improvement and the most critical observational needs. The results are used to understand the new and improved capability required for the next-generation SRF systems and to support the design of the Fire and Smoke Model Evaluation Experiment (FASMEE) and other field campaigns. The next-generation SRF systems should have more coupling of fire, smoke and atmospheric processes. The development of the coupling capability requires comprehensive and spatially and temporally integrated measurements across the various disciplines to characterize flame and energy structure (e.g. individual cells, vertical heat profile and the height of well-mixing flaming gases), smoke structure (vertical distributions and multiple subplumes), ambient air processes (smoke eddy, entrainment and radiative effects of smoke aerosols) and fire emissions (for different fuel types and combustion conditions from flaming to residual smouldering), as well as night-time processes (smoke drainage and super-fog formation).
Read the review.
Examination of the historical literature indicated that entrapment potential peaks when fire behavior rapidly deviates from an assumed trajectory, becomes extreme and compromises the use of escape routes, safety zones or both. Additionally, despite the numerous safety guidelines that have been developed as a result of analyzing past entrapments, we found issues with the way factual information from these incidents is reported, recorded and stored that make quantitative investigations difficult. To address this, a fire entrapment database was assembled that revealed when details about the location and time of entrapments are included in analyses, it becomes possible to ascertain trends in space and time and assess the relative influence of various environmental variables on the likelihood of an entrapment. Several research needs were also identified, which highlight the necessity for improvements in both fundamental knowledge and the tools used to disseminate that knowledge.
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In 1998, the Joint Fire Science Program (JFSP) was statutorily authorized as a joint partnership between the U.S. Department of the Interior and the U.S. Department of Agriculture Forest
Service. The program provides leadership to the wildland fire science community by identifying high-priority fire science research needs that will enhance the decisionmaking ability of
managers to meet their objectives. This publication celebrates and describes the JFSP’s contributions to and impact on the wildland fire community over the past 20 years.
Despite a clear link between drought and wildfire, there is currently a lack of information for stakeholders at the regional and local levels for improved wildfire risk management using drought early warning information. Fire managers and other specialized fire professionals, such as Incident Meteorologists, will increasingly need to effectively use drought information in forecasts of fire behavior at fire incidents, and in long-term planning (i.e., seasonal fire potential outlooks) as the climate continues to warm along with shifts in the timing and duration of fire seasons.
This webinar highlights recent efforts to incorporate drought-wildfire linkages into the National Integrated Drought Information System (NIDIS) California-Nevada Drought Early Warning System. Research has shown that drought indices which are both multi-scalar and incorporate evaporative demand are most strongly correlated to fuel moisture. Testing of the Evaporative Demand Drought Index (EDDI) was conducted by Predictive Services in Northern California during the 2018 fire season. Web tools have been developed (and some that are still in development) to access EDDI, other drought indices, and remote sensing data (often with global coverage) that can potentially benefit wildland fire management in Alaska. Focus will be on EDDI tools developed at NOAA’s Physical Science Division and Climate Engine (app.climateengine.org) developed jointly between the Desert Research Institute and University of Idaho.
Presented by Dan McEvoy, Desert Research Institute and Western Regional Climate Center, Reno, NV.
A rotor-wing unmanned aerial system (UAS) hovering above a fire provides a static, scalable sensing platform that can characterize terrain, vegetation, and fire coincidently. This study presents methods for collecting consistent time-series of fire rate of spread (RoS) and direction in complex fire behavior using UAS-borne NIR and Thermal IR cameras. Using a hybrid temperature-gradient threshold approach with data from two prescribed fires in dry conifer forests, the methods characterize complex interactions of observed heading, flanking, and backing fires accurately.
View report.
Wildland firefighters in the United States are exposed to a variety of hazards while performing their jobs in America’s wildlands. Although the threats posed by vehicle accidents, aircraft mishaps, and heart attacks claim the most lives, situations where firefighters are caught in a life-threatening, fire behavior-related event (i.e. an entrapment) constitute a considerable danger because each instance can affect many individuals. In an attempt to identify the scope of understanding of the causes of firefighter entrapments a review of the pertinent literature and a compilation and synthesis of existing data were undertaken.
The Hot-Dry-Windy Index (HDW) was designed to help users determine which days are more likely to have adverse atmospheric conditions that make it more difficult to manage a wildland fire. It combines weather data from the surface and low levels of the atmosphere into a first-look product.
HDW was designed to be very simple – a multiplication of the maximum wind speed and maximum vapor pressure deficit (VPD) in the lowest 50 or so millibars in the atmosphere. Because HDW is affected by heat, moisture, and wind, seasonal and regional variability can be found when comparing HDW values from different locations and times.
Linear fuel breaks may help reduce wildfire intensity and spread, and at the same time improve firefighting effectiveness, but their ecological impacts may include habitat loss and fragmentation, as well as facilitation of species movement. There is very little peer‐reviewed science available to inform land managers about the ecological effects of fuel breaks. As such, land managers may face trade‐offs with uncertain outcomes: either substantially alter habitats with fuel breaks to potentially minimize wildfire impacts or risk increased habitat loss and degradation from wildfire. The Great Basin region of the western US offers an opportunity to better understand the relative costs and benefits of fuel breaks, and to identify key knowledge gaps
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On average, one third of the area burned by predicted wildfires was non-local, meaning that the source ignition was on a different land tenure. Land tenures with smaller parcels tended to receive more incoming fire on a proportional basis, while the largest fires were generated from ignitions in national parks, national forests, public and tribal lands. Among the 11 western States, the amount and pattern of cross-boundary fire varied substantially in terms of which land tenures were mostly exposed, by whom and to what fire sizes. We also found spatial variability in terms of community exposure among States, and more than half of the predicted structure exposure was caused by ignitions on private lands or within the wildland-urban interface areas. This study addressed gaps in existing wildfire risk assessments, that do not explicitly consider cross-boundary fire transmission and do not identify the sources of fire. The results can be used by State, Federal, and local fire planning organizations to help improve risk mitigation programs.