Research Database
Displaying 1 - 20 of 175
Global Synthesis of Quantification of Fire Behaviour Characteristics in Forests and Shrublands: Recent Progress
Year: 2025
Purpose of ReviewThe behaviour of wildland fires, namely their free spreading nature, destructive energy fluxes and hazardous environment, make it a phenomenon difficult to study. Field experimental studies and occasional wildfire observations underpin our understanding of fire behaviour. We aim to present a global synthesis of field-based studies in forest and shrublands fuel types published since 2003 with a focus on the most commonly measured fire behaviour attributes, namely rate of fire spread, ignition and spread sustainability, flame characteristics, fuel consumption…
Publication Type: Journal Article
Wildland fire entrainment: The missing link between wildland fire and its environment
Year: 2025
Wildfires are growing in destructive power, and accurately predicting the spread and intensity of wildland fire is essential for managing ecological and societal impacts. No current operational models used for fire behavior prediction resolve critical fire-atmospheric coupling or nonlocal influences of the fire environment, rendering them inadequate in accounting for the range of wildland fire behavior scenarios under increasingly novel fuel and climate conditions. Here, we present a new perspective on a dominant fire-atmospheric feedback mechanism, which we term wildland fire entrainment (…
Publication Type: Journal Article
Comprehensive methodology for tracking burning firebrands in a vertical wind tunnel using multi-view video analysis
Year: 2025
MethodsA custom firebrand tracking system consisting of three synchronised video cameras positioned orthogonally around the working section of a vertical wind tunnel was built and bespoke image processing algorithms developed to automatically reconstruct the 3D trajectory and combustion behaviour of a bark sample.Key resultsThe system was found to accurately estimate bark sample position as well as spatial velocity, orientation changes and burnout profile.ConclusionsA robust and accurate methodology to track the dynamic trajectory and…
Publication Type: Journal Article
COVID‐19 Fueled an Elevated Number of Human‐Caused Ignitions in the Western United States During the 2020 Wildfire Season
Year: 2025
The area burned in the western United States during the 2020 fire season was the greatest in the modern era. Here we show that the number of human-caused fires in 2020 also was elevated, nearly 20% higher than the 1992–2019 average. Although anomalously dry conditions enabled ignitions to spread and contributed to record area burned, these conditions alone do not explain the surge in the number of human-caused ignitions. We argue that behavioral shifts aimed at curtailing the spread of COVID-19 altered human-environment interactions to favor increased ignitions. For example, the number of…
Publication Type: Journal Article
Reliability of satellite-based vegetation maps for planning wildfire-fuel treatments in shrub steppe: Inferences from two contrasting national parks
Year: 2025
Protecting habitat threatened by increasing wildfire size and frequency requires identifying the spatial intersection of wildfire behavior and ecological conditions that favor positive management outcomes. In the perennial sagebrush steppe of Western North America, invasions by fire-prone annual grasses are a key concern, and management of them requires reliable maps of vegetation cover, fuels, and wildfire behavior. We compared commonly used, publicly available vegetation cover and fuels maps, specifically the Rangeland Analysis Platform (RAP) and LANDFIRE, with field-based assessments at…
Publication Type: Journal Article
Mental health risk for wildland firefighters: a review and future directions
Year: 2025
Wildland fire is increasingly a consequence of the climate crisis, with growing impacts on communities and individuals. Wildland firefighters are critical to the successful management of wildland fire, yet very limited research has considered mental health in this population. Although a wealth of research in mental health risk and associated risk and protective factors exists for structural firefighters, unique demands of wildland firefighting such as the seasonal nature of work, the length and intensity of shifts, and the often geographically isolated working conditions, among other factors…
Publication Type: Journal Article
Long-range PM2.5 pollution and health impacts from the 2023 Canadian wildfires
Year: 2025
Smoke from extreme wildfires in Canada adversely affected air quality in many regions in 20231,2. Here we use satellite observations, machine learning and a chemical transport model to quantify global and regional PM2.5 (particulate matter less than 2.5 μm in diameter) exposure and human health impacts related to the 2023 Canadian wildfires. We find that the fires increased annual PM2.5 exposure worldwide by 0.17 μg m–3 (95% confidence interval, 0.…
Publication Type: Journal Article
Short-term impacts of operational fuel treatments on modelled fire behaviour and effects in seasonally dry forests of British Columbia, Canada
Year: 2025
Background: In response to increasing risk of extreme wildfire across western North America, forest managers are proactively implementing fuel treatments.Aims: We assessed the efficacy of alternative combinations of thinning, pruning and residue fuel management to mitigate potential fire behaviour and effects in seasonally dry forests of interior British Columbia, Canada.Methods: Across five community forests, we measured stand attributes before and after fuel treatments in 2021 and 2022, then modelled fire behaviour and effects using the…
Publication Type: Journal Article
Experimental study on the evolution of canyon fire spread behavior under different terrains and the critical conditions for eruptive fire
Year: 2025
BackgroundThe spread of canyon fire often involves sudden acceleration, which is related to eruptive fire.AimsThe purpose of the study is to explore the pattern of fire line evolution and rate of spread (ROS) with topographic conditions in canyon fire, and to clarify the critical conditions for and mechanism of eruptive fire.MethodsA systematic experimental study on canyon fire was conducted by igniting dead pine needles with a point ignition.Key resultsFour different types of fire line contours were identified under…
Publication Type: Journal Article
Fine Particulate Matter From 2020 California Wildfires and Mental Health–Related Emergency Department Visits
Year: 2025
Importance: A growing body of research suggests that exposure to fine particulate matter (PM2.5; particle size 2.5 microns or smaller) may be associated with mental health outcomes. However, the potential impact of wildfire-specific PM2.5 exposure on mental health remains underexplored.Objective: To investigate whether wildfire-specific PM2.5 exposure may be associated with emergency department (ED) visits for mental health conditions, including all-cause and for psychoactive substance use, nonmood psychotic disorders, anxiety, depression, and other mood-affective disorders during the…
Publication Type: Journal Article
Review of thermal behaviour of firebrands and their role in fuel bed and structure ignition
Year: 2025
Firebrands or embers are a crucial phenomenon in wildfire behaviour. Firebrands – small, burning or smouldering pieces of wood or other flammable materials – can be carried by wind considerable distances, leading to ignition of new fires ahead of the main fire front. This process, called spotting, significantly contributes to the rapid spread of fires, particularly in wildland–urban interface (WUI) areas. Spot fires pose a severe threat to people and properties. Better understanding the thermal behaviour of firebrands and their ability to ignite various natural fuel beds and structural…
Publication Type: Journal Article
Enhancing fire emissions inventories for acute health effects studies: integrating high spatial and temporal resolution data
Year: 2025
Background: Daily fire progression information is crucial for public health studies that examine the relationship between population-level smoke exposures and subsequent health events. Issues with remote sensing used in fire emissions inventories (FEI) lead to the possibility of missed exposures that impact the results of acute health effects studies.Aims: This paper provides a method for improving an FEI dataset with readily available information to create a more robust dataset with daily fire progression.Methods: High temporal and spatial…
Publication Type: Journal Article
Role of Forensic Anthropology in the Search and Recovery of Fatal Wildland Fire Victims
Year: 2025
The search and recovery process of fatal fire victims is one of the greatest challenges in forensic anthropology, especially in large-scale wildland fire disasters. Burned human remains can exhibit significant variation in their degree of preservation depending on the temperature of the fire, the length of exposure to the heat source, and intrinsic characteristics of the victim (e.g., body size, age, and bone density). Wildland fire victims typically exhibit characteristics of the final stages of burning (i.e., nearly complete to complete calcination). The search for burned human remains is…
Publication Type: Journal Article
Extreme Weather Magnifies the Effects of Forest Structure on Wildfire, Driving Increased Severity in Industrial Forests
Year: 2025
Despite widespread concern over increases in wildfire severity, the mechanisms underlying this trend remain unclear, hampering our ability to mitigate the severity of future fires. There is substantial uncertainty regarding the relative roles of extreme weather conditions, which are exacerbated by climate change, and forest management, in particular differences between private industrial timber companies and public land agencies. To investigate the effects of extreme weather and forest management on fire severity, we used light detection and ranging (LiDAR) data to characterize pre-fire…
Publication Type: Journal Article
Enhancing fire emissions inventories for acute health effects studies: integrating high spatial and temporal resolution data
Year: 2025
Background: Daily fire progression information is crucial for public health studies that examine the relationship between population-level smoke exposures and subsequent health events. Issues with remote sensing used in fire emissions inventories (FEI) lead to the possibility of missed exposures that impact the results of acute health effects studies.Aims: This paper provides a method for improving an FEI dataset with readily available information to create a more robust dataset with daily fire progression.Methods: High temporal and spatial resolution burned area information from two FEI…
Publication Type: Journal Article
Wildfire smoke exposure and mortality burden in the USA under climate change
Year: 2025
Wildfire activity has increased in the USA and is projected to accelerate under future climate change1,2,3. However, our understanding of the impacts of climate change on wildfire activity, smoke and health outcomes remains highly uncertain because of the difficulty of modelling the causal chain from climate to wildfire to air pollution and health. Here we quantify the…
Publication Type: Journal Article
Multifactor Change in Western U.S. Nighttime Fire Weather
Year: 2025
Reports from western U.S. firefighters that nighttime fire activity has been increasing during the spans of many of their careers have recently been confirmed by satellite measurements over the 2003–20 period. The hypothesis that increasing nighttime fire activity has been caused by increased nighttime vapor pressure deficit (VPD) is consistent with recent documentation of positive, 40-yr trends in nighttime VPD over the western United States. However, other meteorological conditions such as near-surface wind speed and planetary boundary layer depth also impact fire behavior and exhibit…
Publication Type: Journal Article
Temporal and spatial pattern analysis of escaped prescribed fires in California from 1991 to 2020
Year: 2025
Background: Prescribed fires play a critical role in reducing the intensity and severity of future wildfires by systematically and widely consuming accumulated vegetation fuel. While the current probability of prescribed fire escape in the United States stands very low, their consequential impact, particularly the large wildfires they cause, raises substantial concerns. The most direct way of understanding this trade-off between wildfire risk reduction and prescribed fire escapes is to explore patterns in the historical prescribed fire records. This study investigates the spatiotemporal…
Publication Type: Journal Article
Climate Change Contributions to US Wildfire Smoke PM2.5 Mortality Between 2006-2020
Year: 2025
RATIONALE Wildfires have increased in frequency and intensity due to climate change and now contribute to nearly half of the annual average of fine particulate matter in the US. While the effects of short-term wildfire-PM2.5 exposure on respiratory diseases are well-described, the impact of climate change on longer duration wildfire-PM2.5 mortality is unknown. Our aim was to determine the contribution of anthropogenic climate change to wildfire smoke PM2.5 mortality on a county-level across the conterminous US between 2006-2020. METHODS We use an attribution model to compare observed wildfire…
Publication Type: Journal Article
Intensifying Fire Season Aridity Portends Ongoing Expansion of Severe Wildfire in Western US Forests
Year: 2025
Area burned by wildfire has increased in western US forests and elsewhere over recent decades coincident with warmer and drier fire seasons. However, high–severity fire—fire that kills all or most trees—is arguably a more important metric of fire activity given its destabilizing influence on forest ecosystems and direct and indirect impacts to human communities. Here, we quantified area burned and area burned severely in western US forests from 1985 to 2022 and evaluated trends through time. We also assessed key relationships between area burned, extent and proportion burned severely…
Publication Type: Journal Article