By N. Bénichou, M. Adelzadeh, J. Singh, I. Gomaa, N. Elsagan, M. Kinateder, C. Ma, A. Gaur, A. Bwalya, and M. Sultan

Fires in the wildland-urban interface (WUI) have become a global issue, with disasters taking place all over the world recently. The drivers of increasing WUI fire risk—increasing population and expansion of urban areas into wildlands, and climate change—are global-scale phenomena. In the coming decades, WUI fire risk is expected to increase both in regions with a long history of fires and in regions that have had been less affected over past decades. WUI fires can cause the ignition of many structures through the spread of flames and radiant heat and the deposition of burning embers over a short period of time. This can overwhelm protection capabilities, lead to large evacuations, and cause disasters with the potential for the total loss of hundreds of structures in a few hours.

As discussed in Chapter 1 of this Guide, over the last decade, an average of 5 533 wildfires have occurred each year in Canada, involving 2.9 million hectares of wildland area. The number of evacuations caused by wildfires increased by about 1.5 evacuations per year between 1980 and 2014, with more than 20 evacuations per year after 2010. The substantial negative impacts of WUI fires were illustrated by the Okanagan Mountain Park Fire, which affected Kelowna in 2003; the Flat Top Complex Wildfire, which destroyed significant parts of Slave Lake in 2011; and the Horse River Fire, which immensely affected Fort McMurray in 2016 and was the most costly insured loss event in Canadian history. These disasters resulted in a loss of over 2 400 structures and roughly 3 400 dwelling units. Total insured losses from these wildland fire disasters and the 2017 wildland fire catastrophic events in British Columbia are currently estimated to be $4.8 billion. Despite all efforts, wildfires pose a significant challenge to the residential population, to mitigation efforts, and to existing infrastructure when located in a WUI setting. Wildfires are likely to become more severe and frequent as a result of climate change.

National Research Council Canada: Ottawa, ON. 2021. 192 pp.

Heather Kreidler, Rapporteur; Board on Environmental Change and Society; Board on Agriculture and Natural Resources; Division of Behavioral and Social Sciences and Education; Division on Earth and Life Studies; National Academies of Sciences, Engineering, and Medicine

Over the past two decades, wildfires in western North America have significantly increased in frequency, magnitude, and severity. Scientists have documented three leading causes: a century of suppression and inadequate forest management that has led to overly dense, fuel-rich forests; climate change, which has turned woodlands and grasslands into hot, dry tinderboxes; and the spread of urbanization, which has increased the probability of man-made ignitions. Less well known are the environmental and social implications associated with the acceleration of these trends.

To explore these concerns and to identify possible policy responses, the National Academies of Sciences, Engineering, and Medicine's Board on Environmental Change and Society, in partnership with the Royal Society of Canada, convened a workshop in June 2024, "The Social and Ecological Consequences of Future Wildfire in the West". Over two days, two dozen wildfire experts and a hybrid audience of over 200 participants explored the history, current state, and anticipated future of wildfire science and policy across the western United States and Canada. This publication summarizes the presentations and discussions of the workshop.

National Academies of Sciences, Engineering, and Medicine. 2024. Social-Ecological Consequences of Future Wildfires and Smoke in the West: Proceedings of a Workshop. Washington, DC: The National Academies Press. https://doi.org/10.17226/27972.

Contributor(s): National Academies of Sciences, Engineering, and Medicine; Division on Earth and Life Studies; Board on Chemical Sciences and Technology; Committee on the Chemistry of Urban Wildfires

Wildfires in America are becoming larger, more frequent, and more destructive, driven by climate change and existing land management practices. Many of these fires occur at the wildland-urban interface (WUI), areas where development and wildland areas overlap and which are increasingly at risk of devastating fires as communities continue to expand into previously undeveloped areas. Unlike conventional wildfires, WUI fires are driven in part by the burning of homes, cars, and other human-made structures and in part by burning vegetation. The interaction of these two types of fires can lead to public health effects that are unique to WUI fires.

This report evaluates existing and needed chemistry information that decision-makers can use to mitigate WUI fires and their potential health impacts. It describes key fuels of concern in WUI fires, especially household components like siding, insulation, and plastic. It examines key pathways for exposure, including inhalation and ingestion, and identifies communities vulnerable to exposure. The report recommends a research agenda to inform response to and prevention of WUI fires, outlining needs in characterizing fuels and predicting emissions and toxicants.

National Academies of Sciences, Engineering, and Medicine. 2022. The Chemistry of Fires at the Wildland-Urban Interface. Washington, DC: The National Academies Press. https://doi.org/10.17226/26460. .2022. 215p.

U.S. Forest Service

Under this strategy, the Forest Service will work with partners to engineer a paradigm shift by focusing fuels and forest health treatments more strategically and at the scale of the problem, using the best available science as the guide. At the Forest Service, we now have the science and tools we need to size and place treatments in a way that will truly make a difference. We will focus on key “firesheds”—large forested landscapes and rangelands with a high likelihood that an ignition could expose homes, communities, and infrastructure to wildfire. Firesheds, typically about 250,000 acres in size, are mapped to match the scale of community exposure to wildfire.

Our new management paradigm builds on the National Cohesive Wildland Fire Management Strategy, Our new management paradigm builds on the National Cohesive Wildland Fire Management Strategy, including efforts to create fire-adapted communities and other collaborative strategies for cross-boundary treatments, including Cohesive Strategy projects and Shared Stewardship agreements. We will build on our long-standing work and relationships with U.S. Department of the Interior agencies. We will work collaboratively with States, Tribes, local communities, private landowners, and other stakeholders to adapt lessons learned into a coordinated and effective program of work.

U.S. Forest Service. 2022. 35p.

By Alexander Maranghides, Eric D. Link, Christopher U. Brown, William Mell, Steven Hawks, Mike Wilson, Will Brewer, Robert Vihnanek, William D. Walton

The Camp Fire ignited on November 8, 2018 in the foothills of the Sierra Nevada in Butte County, California. The first 24 hours were characterized by a fast-moving fire with initial spread driven by high winds up to 22 m/s (50 mi/h) and long-range spotting up to 6.3 km (3.9 mi) into the community. The fire quickly impacted the communities of Concow, Paradise, and Magalia. The Camp Fire became the most destructive and deadly fire in California history, with over 18,000 destroyed structures, 700 damaged structures, and 85 fatalities. After a preliminary reconnaissance, it was determined that abundant data was available to support an in-depth case study of this devastating wildland-urban interface (WUI) fire to increase our understanding of WUI fire spread, fire behavior, evacuation, and structure response. The methodology guiding the case study and a detailed timeline reconstruction of the fire progression and fire behavior are presented. Over 2200 observations about fire spread and behavior were collected during the case study. Subsequent reports will detail additional aspects of the incident including emergency response and evacuation, and defensive actions and structure response. This study has identified that Butte County and the Town of Paradise were well prepared to respond to a WUI fire, that the Camp Fire grew and spread rapidly and that multiple factors contributed to the rapid growth and spread of the Camp Fire. Additionally, this study identified the importance of the wildland fire ignition location relative to the community, that multiple parcel-level fire spread pathways caused structure ignitions, and that WUI fire spread impacted the affected communities in multiple ways beyond the destruction of residential and commercial properties.

Technical Note (NIST TN) - 2135. 2021. 425p.

By The Los Angeles County

The Los Angeles County After Action Review of the Woolsey Fire evaluates the incident’s response, identifies areas for improvement, and offers recommendations for future preparedness, focusing on agency coordination, communication, evacuation, and recovery efforts.

• The Woolsey Fire After Action Review (AAR) provides a comprehensive analysis of the event, highlighting both successes and areas for improvement.
• The AAR process involved data collection, interviews, and cross-checking to ensure a detailed account of the incident.
• Key sections of the report include an executive summary, timeline of events, findings, and recommendations.
• Recommendations are divided into near-term and longer-term policy actions, focusing on response, communication, evacuation, and recovery.
• Appendices provide historical context and background information on involved agencies and regional fire history.
• The report emphasizes planning for future disasters in areas prone to wildfires and earthquakes.
• Training and coordination among agencies, such as the County Sheriff’s Department and Public Works, are highlighted as crucial for effective disaster response.
• Historical fire data shows a repetitive fire cycle in the region, underlining the importance of preparedness and mitigation efforts.

LLos Angeles County. 2019. 203p.

By United States. Federal Emergency Management Agency

From the document: "I am pleased to share the 2023 Hazard Mitigation Assistance Program and Policy Guide (HMA Guide) as FEMA's updated comprehensive policy handbook to govern mitigation grant programs. This document replaces the 2015 HMA Guidance and HMA Guidance Addendum. Since the last update and publication, many developments have impacted our mitigation grant programs. They include the passage of the Disaster Recovery Reform Act of 2018; the rollout of a new hazard mitigation grant program--Building Resilient Infrastructure and Communities (BRIC); significantly increased funding and accessibility to mitigation programs via the Infrastructure Investments and Jobs Act of 2021; and prioritization of new resilience concepts to accelerate and advance mitigation investment, such as those outlined in the National Mitigation Investment Strategy and FEMA's Building Codes Strategy. [...] FEMA's Hazard Mitigation Assistance grant programs provide funding for actions that address risks to and reduce disaster suffering from events like wildfires, drought, extreme heat, hurricanes, earthquakes and flooding. The updated HMA Guide provides helpful information for state, local, tribal and territorial governments seeking to successfully navigate the application and grant lifecycle processes. And with the unprecedented funding that has been made available for mitigation over the past few years, it has never been more important to reduce the barriers to accessing these grant dollars and get them into the right hands for the most impactful mitigation projects."

Washington DC. United States. Federal Emergency Management Agency. 2023. 623p.

By United States. White House Office

From the document: "Near-Earth Objects (NEOs) are asteroids and comets that orbit the Sun but have orbits that can bring them into Earth's neighborhood--within 30 million miles of Earth's orbit. Planetary defense encompasses all the capabilities needed to detect and warn of potential 10-meter and larger NEO impacts with Earth, and to either prevent such an event or mitigate the possible effects of an impact. This 'National Preparedness Strategy and Action Plan for Near-Earth Object Hazards and Planetary Defense' (2023 Planetary Defense Strategy) updates the United States' first comprehensive Near-Earth Object Preparedness Strategy and Action Plan, released in 2018. The 2023 Planetary Defense Strategy builds on existing efforts by Federal Departments and Agencies to address the hazard of NEO impacts, includes evaluation of where progress has been made since 2018, and focuses future work on planetary defense across the U.S. government."

Washington DC. United States. White House Office. 2023. 38p.