Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
Summary
Calfatters analysis found that by 2020, nearly 14 million Californians had lived in a scattered 7 million zone, which made up the Wildland urban interface. And when the fires swell it, they often leave destruction.
In just one month 2025 is the second most destructive fire year in the history of California, with over 16,000 homes and other structures being damaged or destroyed by two fires in the Los Angeles region. Most of these structures were in neighborhoods, where the boundaries between human development and natural landscapes blur-Ryon fire and researchers call the urban interface or WUI (Woo-Ee).
When a wild fire approaches one of these areas, the results can be dangerous as the fire can pass from the consumption of trees, shrubs and plants to the ingestion of homes and other structures, often built in ways that are vulnerable to burning. And also, where California has been building homes for decades – nearly 45% of homes built between 1990 and 2020, are located in places with lots of vegetation ready for fire.
Calfatters’ analysis found that by 2020, nearly 14 million Californians, or 1 in 3, lived in the scattered 7 million zone, which made up the WUI. And it’s not just a problem for the Californians living in rural states: all 58 California counties have WUIS, along with many areas across the country. Wui is growing by about 2 million acres a year across the country, according to the US Fire Administration.
Sarah McCfri, a social scientist who has been working for the American Forest Service for decades, says it in another way: structural fires and fires in the wild – and the interface is where the two gather.
Just because the development is located within the WUI does not mean that there will be a fire, but there may be deadly and destructive consequences if it does. While below 3% of the state WUI has been affected by a fire in the last decade, thousands of homes in the area have been destroyed, according to an analysis of Salmatters.
“I think it is sometimes more useful to talk about building places of danger of wild fire.”
Judson Boomhower, Assistant at UC San Diego Economics Department, in Wildland’s Urban Interface
Since 2018, Cal Fire, the State Fire Agency, inspects all buildings within 100 meters of a fire perimeter and evaluate the level of damage. The most destructive fires in the history of California have largely damaged or destroyed homes within the WUI, including the two largest fires in Los Angeles County this year -the Palisades and Fires of Ethan, which demolished entire neighborhoods and killed 28 people Since January 24th.
Ethan’s fire died at least 17 people and destroyed more than 9,400 structures, approximately 9,200 Of which they were within the WUI, as is a large part of Altadena, where the San Gabriel Valley rises to meet the San Gabriel Mountains. The map below shows inspections of buildings conducted by Cal Fire after a fire in Ethan, along with WUI, illustrating how destructive a major fire for suburban areas can be.
The other great fire in LA, the fire of Palisades, was apparently moving in the mountains of Santa Monica to the Pacific Palisades, a coastal neighborhood in Los Angeles, which is almost entirely within the WUI. The winds of the hurricane strength intensified and spread the flames and destroyed at least 6,800 structures while nearly 4 100 they were Unharmed.
The most deathly and most destructive fire in the history of California, the camp of the camp, destroyed the city of Paradise in Bt in 2018, when the massive flame burned both the natural and the environment. The fire damaged or destroyed nearly 20,000 structures and killed 85 people.
Having a home in WUI does not guarantee that it will burn if a wild fire covers the neighborhood. Many factors contribute to this opportunity, such as the year when the home is built, the practices of fuel management nearby, which are intended to reduce stored objects nearby – and what some people call “time” and the rest of us call Good luck. That is why there are pictures of uncorrected homes to their destroyed neighbors after such destructive fires in California.
Nevertheless, some experts say that WUI is not the only one or maybe even the best way to measure danger or risk of fire because it is not designed for it. It can collapse a shade to carefully focus our attention.
“There is nothing about the risk of fire on the WUI map,” McCfri said. “There are some documents that show that approximately one -third of the lost houses in fires are not in WUI, right? But we are focusing on all our attention to WUI. “
An example of how the border between the wild and urban landscape does not necessarily become a high risk of fire is the Tubbs fire for 2017 in Sonoma County. The Coffey Park neighborhood in Santa Rosa was almost leveled, although it is not technically in WUI, right next to it. The fire destroyed more than 5,000 structures and killed 22 people.
“In fact, there is a legitimate or technical definition of the Wildland Urban Forestry Interface, and this is related to the number of structures per hectare and the amount of vegetation,” says Judson Bumaur, an assistant in the UC San Diego Economics Division. “I think it is sometimes more useful to talk about building places of danger of wild fire.”
Ways to reduce the risk of fire from house to house to house depends on the nuances of each neighborhood, especially how densely packed the buildings are.
“If the houses are, you know, at 80 or 100 feet, then our whole focus on the protective space and Zone Zero, and all these things probably have a much more meaning,” McCfri said. “Because then, you know, there is a great chance for my house to survive if I did all this, even if my neighbor’s house ignited.”
On the other hand, some of the homes in the Pacific Palisades look so close to each other that even if they guarantee that there is nothing flammable within five feet, it may not have prevented the spread of the fire, McCfric said. A law Signed by governor Gavin Newo in September 2021, it requires the State Council of Forestry and Fire Protection and the State Fire Marshal to make proposals for the creation of a resistant Ember zone within five feet of the structure in a high -weight area of fire.
State intervention has helped reduce the destruction of these more prone to fire areas. Surveys from 2021 He concluded that the homes in California, built after 2008, were almost half -more likely to be destroyed than those built in 1990, if a fire burned through the neighborhood, to a large extent due to improved construction code regulations.
California faces a chronic shortage of housing and megaphirs strengthened by climate change, but with millions of residents already living in the city interface of wildlife, state politicians will face questions about how to protect people and where to recover after strikes of disasters.
