Back to blogUnderstanding Wildfire Risk Assessment in Wildland Urban Interfaces


What is a WUI?

Wildland Urban Interfaces (WUIs) are communities that are located in transitory areas between forested wildlands and cityscapes. They are typically characterized by a large amount of brush and foliage amongst the houses. WUIs are a large concern for fire managers as they are at high risk during fire season. This is due to a combination of hazards that WUIs face. Houses surrounded by brush have a high risk of damage because foliage can pass ignitions to homes. Additionally wildlands are more prone to wildfires and nearby communities thus have a higher potential to experience adverse from fires. As human populations grow our cities expand and so do WUIs. In 2021 WUIs were the fastest growing type of land use. As WUIs grow, risk assessment will play an important role in protecting WUIs and creating opportunities to adapt to wildfires.

WUIs and Climate

A large theme in evaluating fire risk is understanding its occurrence. As our climate warms, wildfires will start to become more and more common. Droughts occur more often, high wind events are becoming more regular, and fire season lengths are increasing. Alaskan boreal forests for example are experiencing large changes to the hydraulic cycle affecting the growing seasons and increasing forest vulnerability. This pattern is continued in North American Forests. The Pacific Northwest experienced massive fire events in recent summers the effects of which can be attributed to a warming climate.

Additionally old resource management strategies have resulted in the build up of unburned fuels. This is due to policy that emphasized forests as resources and wildfires as loss events. The 10 a.m. policy established in 1935 was a policy that required fires be put out by 10 a.m. the following day. Fire suppression practices were enforced into the 1970s until it was finally acknowledged that fires created ecological benefits for forests, and suppression practices decreased. In Wildland Urban Interfaces (WUIs), the practice of fire suppression has led to the formation of unrealistic community expectations. Unlike towns accustomed to natural disasters like earthquakes and tsunamis, which are ingrained as a reality of life, rural communities in heavily forested areas remained sheltered from natural fire cycles until the 1970s. It’s only in recent years that forested communities have begun to recognize the risks associated with wildfires and the need for proactive preparation.This issue compounded with a buildup of fuel and climate change has left communities in WUIs surprised and unprepared for the megafires now common to the West Coast.

Homeowner Perspectives

Individuals all have different preferences that define the amount of satisfaction they can receive from having some level of risk. In economic frameworks we can describe risk as a preference function where an individual can receive different payoffs from a given risk. For example, A rhododendron bush provides a beautiful view and shade but also creates a fire risk as foliage near a home can more easily catch fire. Each individual will be more or less inclined to different risk levels based on their preferences. Some community members will prioritize prevention, while others prefer different aesthetics. Thus WUIs are made up of a variety of levels of risk depending on homeowner preferences.

Community preparation should be a major priority to risk mitigation but can be especially hard to navigate as it can be unclear who is responsible for risk mitigation. In 2011 it was found that the majority of US residents living in fire prone environments took some form of action to mitigate their risks. Additionally the majority of individuals believed that risk mitigation was the responsibility of individual property owners. Although it is helpful to have defined expectations, knowledge of risk is not enough to encourage mitigation. Effective strategies in community risk mitigation involvement have discussed creating a culture of preparedness. This empowers community members to partake in mitigation efforts, inform themselves on evacuation plans, and community specific issues.

Land Development and Management Practices

WUI’s development is characterized by demand for housing. People migrate in and out of WUIs and choose where to build in wildlands. In the long run house buyers do not consider natural disasters when purchasing a home. Risk is also underestimated by homeowners. Following a wildfire risk expectation decreases because property owners and purchasers are less likely to expect a fire to occur more than once in an area. Additionally homeowners don’t carry the full responsibility for wildfire risk due to insurance policies. Fire risk is broadley under-represented in the housing market. As a response insurance companies have begun upping rates and refusing to renew contracts due to the high risk.

Land management practices are also useful to Wildland Urban interfaces. Prescribed Burns have been found to be an effective tool to decrease fuel loads additionally thinning can lessen fuel loads. Strategies for forest management have to be as diverse as the habitats they work to protect. Land managers must navigate public policy between federal and state levels that often slow actions to allow prescribed burns. Many of the state level slow downs can be reasonable as state governments wish to fully consider the public health ramifications of air quality affects and reductions in visibility caused by prescribed burns. Some state policies can inhibit productive prescribed burns due to insufficient areas of effect. This can make effective land management extremely difficult to achieve.

Major Challenges for WUI protection and fire Preparations

Responsibility for risk is a difficult topic; fire managers, insurance companies, and the inhabitants of WUIs all can have differing views on who is responsible for the prevention of and protection from fires. Houses built to firewise standards are more likely to survive wildfires. Firewise programs promote the construction of a defensible space. They encourage the use of fireproof roofs and remove vegetation near houses . Local governments encourage the adoption of firewise programs because firefighters can more effectively protect structures included within the program. Accessibility to firewise construction is often difficult as homeowners can’t always afford to replace their roofs, or partake in the manual labor to remove brush near their homes. Although Firewise programs are useful for risk mitigation, community organization and accessibility still remain as a large hurdle to their success.

WUIs are a difficult challenge for firefighters to protect. A large amount of vegetation can make some homes entirely undefendable. Additionally the increasing severity of fire seasons stretch firefighting resources thin and decisions have to be made on the feasibility of what structures can be protected. The nature of WUIs proximity to wildlands can also be a challenge as many fires can occur deep in forested lands where there is little infrastructure to transport crews and equipment. Remote fires can be fought with aerial firefighting but these resources are expensive and require extensive levels of training.

Wildfires in Wildland Urban Interfaces (WUIs) have large social and economic consequences for affected communities. The displacement of residents due to evacuations disrupts daily life and can cause emotional distress and uncertainty. Moreover, the loss of homes, businesses, and infrastructure results in significant economic hardship for individuals and the community as a whole. Many residents not only suffer the loss of property but also face the challenge of rebuilding. Additionally, the long-term recovery process is difficult and requires substantial resources, both financial and human. Communities must navigate the complexities of insurance claims, government assistance programs, and infrastructure restoration efforts to recover. In 2023 4.74 billion dollars was spent by the department of the interior on fire suppression and 2.69 million acres were burned.

Approaches to Risk Management

Policy and legislation play a crucial role in addressing wildfire risk in WUIs. Building codes, land-use planning regulations, and incentives for homeowners to implement wildfire-resistant measures are key components of wildfire mitigation strategies. Affective policy can be informed by understanding current fire regimes and situating WUIs within that context. Policy must be able to adapt in response to the extremes posed by climate. Collaborative efforts between government agencies, policymakers, and community members are essential for implementing comprehensive wildfire risk reduction measures and ensuring the resilience of WUIs.

Interagency collaboration is a major need for effective protection of high risk communities. Federal, state, and local government agencies play essential roles in coordinating wildfire response efforts and leveraging resources. Additionally, non-profit organizations and community groups contribute insights and resources to wildfire prevention and preparedness initiatives, fostering community resilience and engagement. Collaboration among these diverse stakeholders facilitates the sharing of information, best practices, and resources, enabling more efficient and coordinated wildfire response and recovery efforts.

An exciting field in wildfire risk assessment is risk mapping. Satellite imagery combined with fire research has allowed for the development of maps that can identify the areas of greatest concern. These maps primarily rely on variables such as human activity, fuel loads, risk of ignition, and climate. Ignitions are characterized as an event when fuel loads are caught on fire; this can be caused by lightning, power lines, or human activity such as farming or recreation. Fuel loads are made up of vegetation, and can include agricultural lands and forests. A hazard is a physical area with the potential to cause damage. Fuel loads are considered hazards. Using GIS mapping fire risk maps are able to model risk effectively, and highlight what areas are most concerning. The maps have been used to effectively influence policy as well as focus the efforts of fire managers.


The management of wildfires in Wildland Urban Interfaces (WUIs) is a growing issue. Policy and legislation play a pivotal role in mitigating wildfire risk in WUIs, emphasizing the importance of informed policy makers and the need to adapt to a changing climate. Land-use planning regulations, and incentives for homeowners to implement wildfire-resistant measures can result in massive benefits. Effective policy implementation requires collaboration and coordination among federal, state, and local government agencies, as well as non-profit organizations and community groups. Adapting to the challenges of wildfire risk in WUIs requires a comprehensive approach that combines policy interventions, community engagement, and technological innovation.

About Camille


Camille Hildum is a graduating Senior at Lewis and Clark College, majoring in Economics with an emphasis on Environmental issues. She is currently completing a thesis on a hedonic price analysis of Oregon homes, focusing on fire risk level, to uncover how wildfire risk impacts property values. Her work aims to understand the economic aspects of risk management, particularly in Wildland Urban Interfaces.

In addition to her academic pursuits, Hildum has developed a curriculum for Community Emergency Response Teams (CERT) as a PE course at her college, under the mentorship of Elizabeth Safran, Director of the Earth System Science Minor and Associate Professor. She also contributed to livestock evacuation efforts with Sound Equine Options during the 2020 Clackamas County wildfires. These experiences have steered her towards a career in emergency management, where she seeks to apply her economic insight and practical skills to enhance community resilience and adaptability to environmental challenges.

Additional Resources

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