Research Database
Displaying 1 - 20 of 147
Mobile radar provides insights into hydrologic responses in burn areas
Year: 2025
Background. Wildfires often occur in mountainous terrain, regions that pose substantial challenges to operational meteorological and hydrologic observing networks. Aims. A mobile, postfire hydrometeorological observatory comprising remote-sensing and in situ instrumentation was developed and deployed in a burnt area to provide unique insights into rainfall-induced post-fire hazards. Methods. Mobile radar-based rainfall estimates were produced throughout the burn area at 75-m resolution and compared with rain gauge accumulations and basin response variables. Key results. The mobile radar was…
Publication Type: Journal Article
The 2023 wildfires in British Columbia, Canada: impacts, drivers, and transformations to coexist with wildfire
Year: 2025
In 2023, all regions of British Columbia (BC) experienced record-breaking fire weather and wildfires, with extreme behavior and social-ecological effects. In total, 2245 wildfires burned 2840 545 hectares. Contemporary wildfires are the culmination of a century of altered human–forest–wildfire relationships, exacerbated by climate change. Transformative change is urgently needed for the ecosystems and communities to be resilient to wildfire. We present six interrelated strategies needed to amplify the pace and scale of change in response to recent wildfire extremes: (1) Immediately diversify…
Publication Type: Journal Article
Compounding effects of climate change and WUI expansion quadruple the likelihood of extreme-impact wildfires in California
Year: 2025
Previous research has examined individual factors contributing to wildfire risk, but the compounding effects of these factors remain underexplored. Here, we introduce the “Integrated Human-centric Wildfire Risk Index (IHWRI)” to quantify the compounding effects of fire-weather intensification and anthropogenic factors—including ignitions and human settlement into wildland—on wildfire risk. While climatic trends increased the frequency of high-risk fire-weather by 2.5-fold, the combination of this trend with wildland-urban interface expansion led to a 4.1-fold increase in the frequency of…
Publication Type: Journal Article
Lightning ignition efficiency in Canadian forests
Year: 2025
Background: Lightning-caused fires have a driving influence on Canadian forests, being responsible for approximately half of all wildfires and 90% of the area burned. We created a climatology (2000–2020) of daily lightning efficiency (i.e., the ratio of cloud-to-ground lightning flashes to lightning-caused wildfires that occurred) over the meteorological summer for four ecozones and a subset of British Columbia (BC) ecoprovinces. We estimated lightning efficiency using data from the Canadian Lightning Detection Network and the Canadian National Fire Database. We used the ERA5…
Publication Type: Journal Article
Are wildfire risk mitigators more prepared to evacuate? Insights from communities in the Western United States
Year: 2025
As the realized experiences of wildfires threatening communities increase, the importance of proactive evacuation preparation and wildfire risk mitigation on private property to reduce the loss of lives and property is shaping wildfire policy and programs. To date, research has focused on pre-wildfire evacuation preparation and risk mitigation independently. This paper examines the substitutability or complementarity of these proactive risk-reducing actions. If mitigation and evacuation preparedness are substitutes, wildfire education programs may take a life-over-property approach. However,…
Publication Type: Journal Article
Wildfire and forest treatments mitigate–but cannot forestall–climate-driven changes in streamflow regimes in a western US mountain landscape
Year: 2025
Warming temperatures and increasingly variable precipitation patterns are reducing winter snowpack and critical late-season streamflows. Here, we used two models (LANDIS-II and DHSVM) in linked simulations to evaluate the effects of wildfire and forest management scenarios on future snowpack and streamflow dynamics. We characterized the biophysical attributes of the areas with the greatest potential for treatments to improve hydrologic functioning and we examined projected trends in flow regimes over the 21st century. We found that, despite a projected increase in total annual flows, there…
Publication Type: Journal Article
Influence of Time‐Averaging of Climate Data on Estimates of Atmospheric Vapor Pressure Deficit and Inferred Relationships With Wildfire Area in the Western United States
Year: 2025
Vapor pressure deficit (VPD) is a driver of evaporative demand and correlates strongly with wildfire extent in the western United States (WUS). Vapor pressure deficit is the difference between saturation vapor pressure (es) and actual vapor pressure (ea). Because es increases nonlinearly with temperature, calculations of time‐averaged VPD vary depending on the frequency of temperature measurements and how ea is calculated, potentially limiting our understanding of fire‐climate relationships. We calculate eight versions of monthly VPD across the WUS and assess their differences. Monthly VPDs…
Publication Type: Journal Article
Shaping Land Use Patterns in the Wildland-Urban Interface: The Role of State and Local Governments in Reducing Exposure to Wildfire Risks
Year: 2025
Development in the wildland-urban interface is increasing exposure to wildfire risks in the western United States. Yet, among the components of risk—hazard, vulnerability, and exposure—mitigating exposure has arguably been most difficult. In this report, we describe the set of interconnected state and local policies that affect development and risk exposure, including local land use planning and zoning, state policies governing insurance, building codes, and infrastructure spending, as well as the role of states as intermediaries between the federal government and localities. We discuss…
Publication Type: Report
A Quantitative Analysis of Firefighter Availability and Prescribed Burning in the Okanogan–Wenatchee National Forest
Year: 2025
Wildfire activity in the western United States has been on the rise since the mid-1980s, with longer, higher-risk fire seasons projected for the future. Prescribed burning mitigates the risk of extreme wildfire events, but such treatments are currently underutilized. Fire managers have cited lack of firefighter availability as a key barrier to prescribed burning. We use both principal component analysis (PCA) and logistic regression modeling methodologies to investigate whether or not (and if yes, under what conditions) personnel shortages on a given day are associated with lower odds of a…
Publication Type: Journal Article
Roof renewal disparities widen the equity gap in residential wildfire protection
Year: 2025
Wildfires are having disproportionate impacts on U.S. households. Notably, in California, over half of wildfire-destroyed homes (54%) are in low-income areas. We investigate the relationship between social vulnerability and wildfire community preparedness using building permits from 16 counties in California with 2.9 million buildings (2013–2021) and the U.S. government’s designation of disadvantaged communities (DACs), which classifies a census tract as a DAC if it meets a threshold for certain burdens, such as climate, environmental, and socio-economic. Homes located in DACs are 29% more…
Publication Type: Journal Article
Increasing Hydroclimatic Whiplash Can Amplify Wildfire Risk in a Warming Climate
Year: 2025
On January 7 and 8, 2025, a series of wind-driven wildfires occurred in Los Angeles County in Southern California. Two of these fires ignited in dense woody chaparral shrubland and immediately burned into adjacent populated areas–the Palisades Fire on the coastal slopes of the Santa Monica Mountains and the Eaton fire in the foothills of the San Gabriel Mountains. Both fires ultimately eclipsed the traditionally-defined “wildland-urban interface” boundaries by burning structure-to-structure as an urban conflagration. The scope of the devastation is staggering; at the time of writing, the…
Publication Type: Report
Compounding effects of climate change and WUI expansion quadruple the likelihood of extreme-impact wildfires in California
Year: 2025
Previous research has examined individual factors contributing to wildfire risk, but the compounding effects of these factors remain underexplored. Here, we introduce the “Integrated Human-centric Wildfire Risk Index (IHWRI)” to quantify the compounding effects of fire-weather intensification and anthropogenic factors—including ignitions and human settlement into wildland—on wildfire risk. While climatic trends increased the frequency of high-risk fire-weather by 2.5-fold, the combination of this trend with wildland-urban interface expansion led to a 4.1-fold increase in the frequency of…
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
Decreasing frequency of low and moderate fire weather days may be contributing to large wildfire occurrence in the northern Sierra Nevada
Year: 2025
Previous analyses identified large-scale climatic patterns contributing to greater fuel aridity as drivers of recent dramatic increases in wildfire activity throughout California. This study revisits an approach to investigate more local fire weather patterns in the northern Sierra Nevada; a region within California that has experienced exceptionally high wildfire activity recently. The annual percentages of fire season days above 90th and 95th percentile Energy Release Component (ERC) values were very low prior to 1994 (Fig. 3). Since 1994, years with noticeable percentages of exceedances (…
Publication Type: Journal Article
Location, Location, Location: The Influence of Local Social Complexity on Risk Reduction Strategies in a WUI Settlement
Year: 2025
This research builds from existing scholarship to highlight the important role social complexity plays on managing and mitigating wildfire risk in the wildland-urban interface. Researchers employed in-depth interviews to uncover similarities and differences in land and wildfire management preferences among what would appear to many to be a relatively homogenous population in a valley on the outskirts of Salt Lake City, Utah. In spite of demographic similarities, researchers found meaningful and complex differences with regard to the local social context of subpopulations within the drainage.…
Publication Type: Journal Article
High fire hazard Wildland Urban Interface (WUI) residences in California lack voluntary and mandated wildfire risk mitigation compliance in Home Ignition Zones
Year: 2025
Wildfire structure losses are increasing globally and particularly in California, USA. Losses can be mitigated in part by changes to the Home Ignition Zone (HIZ), including both home hardening and defensible space. In the United States, there are local, nation-wide, and industry-based home mitigation standards that are enforced or recommended. We explore the standards implementation (California code and two voluntary standards) at 176 participating residences in three Santa Cruz Mountains and two Sierra Nevada Mountains sites. Overall most residences had little compulsory or recommended…
Publication Type: Journal Article
Garden design can reduce wildfire risk and drive more sustainable co-existence with wildfire
Year: 2024
Destructive wildfire disasters are escalating globally, challenging existing fire management paradigms. The establishment of defensible space around homes in wildland and rural urban interfaces can help to reduce the risk of house loss and provide a safe area for residents and firefighters to defend the property from wildfire. Although defensible space is a well-established concept in fire management, it has received surprisingly limited scientific discussion. Here we reviewed guidelines on the creation of defensible space from Africa, Europe, North America, South America, and Oceania. We…
Publication Type: Journal Article
Drought triggers and sustains overnight fires in North America
Year: 2024
Overnight fires are emerging in North America with previously unknown drivers and implications. This notable phenomenon challenges the traditional understanding of the ‘active day, quiet night’ model of the diurnal fire cycle1,2,3 and current fire management practices4,…
Publication Type: Journal Article
Hydrometeorology-wildfire relationship analysis based on a wildfire bivariate probabilistic framework in different ecoregions of the continental United States
Year: 2024
Wildfires are a natural part of the ecosystem in the U.S.. It is vital to classify wildfires using a comprehensive approach that simultaneously considers wildfire activity (the number of wildfires) and burned area. On this basis, the influence of hydrometeorological variables on wildfires can be further analyzed. Therefore, this study first classified wildfire types using a wildfire bivariate probability framework. Then, by considering six hydrometeorological variables, the dominant hydrometeorological variables for different wildfire types in 17 ecoregions of the United States were…
Publication Type: Journal Article
Comparing ground-based lightning detection networks near wildfire points-of-origin
Year: 2024
Lightning detection and attribution to wildfire ignitions is a critical component of fire management worldwide to both reduce hazards of wildfire to values-at-risk and to enhance the potential for wildland fire to provide resource benefits in fire-adapted ecosystems. We compared two operational ground-based lightning detection networks used by fire managers to identify cloud-to-ground strokes within operationally-relevant distances (1.6 km) of the origins of 4408 western United States lightning-ignited wildfires spanning May–September 2020. Applying two sets of constraints–varying…
Publication Type: Journal Article