Linking wildfire risk to social vulnerability

Socially vulnerable groups are significantly over-represented in high wildfire-risk areas across the United States and should be prioritized for targeted mitigation measures, research has found.

A study in the International Journal of Wildland Fire identified census tracts across the US where high wildfire risk and high social vulnerability intersect – and found that American Indian/Alaska Native communities, Hispanic/Latino residents, and mobile home residents are disproportionately concentrated in these areas.

Most of these tracts are located in less populated areas of western and southern states, and concentrated mainly in California, Texas, and Florida.

Exploring the spatial association between wildfire risk and social vulnerability in continental US, International Journal of Wildland Fire.
Exploring the spatial association between wildfire risk and social vulnerability in continental US, International Journal of Wildland Fire.

With nearly 21 million people living in these high-risk, high-vulnerability zones, this research has implications for wildfire mitigation and disaster preparedness, particularly for communities that have historically been underserved.

This is not the first study to make the connection – lead author Professor Jayajit Chakraborty from the University of California, Santa Barbara, explains that we have known for a while that vulnerable communities bear a disproportionate burden from wildfires.

“What we are doing differently is asking where exactly does this happen and using rigorous spatial statistics to answer that,” said Prof Chakraborty.

The study overlaid a number of databases and analytical tools to get the result – mainly, the bivariate Local Indicators of Spatial Associations (LISA), and the Social Vulnerability Index (SVI) that was developed by the Center for Disease Control and Prevention (CDC) to map areas of vulnerability for public health and emergency planners.

The use of LISA at a national scale provided spatial precision. “Previous studies have documented the relationship but had not really pinned down the specific neighborhoods where high wildfire risk and high social vulnerability coincide spatially. That’s the gap we were trying to fill”

So, what does a more precise approach for these communities actually look like? It really depends on the community, Prof Chakraborty says.

“For Indigenous communities, for example, it’s not just about dropping fire mitigation resources in – it’s about meaningful consultation, respecting tribal governance, and supporting things like culturally grounded prescribed burn programs that many tribes have practiced for generations.

“For Hispanic communities, a lot of it comes down to language access and trust issues. Evacuation notices that only exist in English, or disaster relief programs that exclude undocumented residents – these are fixable barriers.

“For mobile home residents, the needs are more physical – these homes are genuinely more fire-vulnerable, and their residents often don’t have the financial resources to make improvements on their own, so you are looking at approaches like subsidized retrofitting or community-level preparedness programs.

“The broader point here is that the High–High tracts identified in this study essentially provide a spatial targeting layer — agencies and decisionmakers can overlay this map with existing program boundaries identify gaps and prioritize investments in overburdened communities.

But how do we explain the LA fires of 2025 that burnt into some of the most expensive real estate in the country?

“The rich can be exposed to wildfire, but they are not socially vulnerable to it in the same way. The findings from our IJWF article show it is American Indian, Hispanic, and mobile home communities – disproportionately in rural western and southern areas – who face the combined burden of high risk and low adaptive capacity,” said Prof Chakraborty.

“The LA fires were a high-visibility event in an economically affluent area; the communities our research identifies face similar or greater physical risk with far fewer resources to prepare, respond, or recover.”

Read the full research paper by Professor Jayajit Chakraborty and Masters Student Sara Soroka in the International Journal of Wildland Fire.

Wildfire exposure felt unequally among elderly, low-income populations

Around 90 percent of all people exposed to wildfires over the past 23 years lived in either California, Oregon, or Washington. Among those, researchers found a disproportionate number were poor, a racial minority, disabled, or over the age of 65.

A recent study examined the “social vulnerability” of the people exposed to wildfires over the last two decades. Social vulnerability describes how persons with certain social, economic, or demographic traits were more susceptible to harm from hazards including wildfires or other natural disasters.

From 2000 to 2021, the number of people in the western United States who lived in fire-affected areas increased by 185 percent, while structure losses from wildfires increased by 246 percent. The vulnerability of the people living there, however, isn’t well known despite these populations potentially never recovering after a disaster strikes.

Researchers asked whether highly vulnerable people were disproportionately exposed to wildfire, how vulnerability has changed over the past 20 years, whether population changes before a fire alter the vulnerability of the population, and whether social vulnerability of people exposed to fires was equal among states.

Each of the three West Coast states recorded disproportionate wildfire exposure of the socially vulnerable; Oregon and Washington had more than 40 percent of their exposed population being highly vulnerable while California had around 8 percent of of those exposed considered highly vulnerable. The most vulnerable populations were also those with low income, while age, minority status, and disability also affected populations’ ability to cope after wildfire.

The number of highly vulnerable people exposed to fire in the three states also increased by 249 percent over the past two decades. An increase in social vulnerability of populations in burned areas was the main contributor to increased exposure in California, while Oregon and Washington saw wildfires increasingly encroaching on vulnerable population areas.

“Our analysis highlights the need to increase understanding of the social characteristics that affect vulnerability, to inform effective mitigation and adaptation strategies,” the study said. “Particular attention to residents who are older, living with a disability, living in group quarters, and with limited English-speaking skills may be warranted, and cultural differences need to be addressed for effective policy development and response.”

Other research published earlier this year, The Path of Flames: Understanding and Responding to Fatal Wildfires, found unequal access and assistance could also play a role in who survives and who dies during catastrophic wildfires. In the study, researchers found that for many of the Paradise, California  residents who died in the 2018 Camp Fire, the inability to evacuate on their own was a major factor in their deaths.

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