The I-Zone: A Human Dimension of Wildland Fire

Fire knows no human boundaries. It does not recognize wealth or poverty, property lines, or political lines. It does not distinguish between abandoned structures or places we consider valuable. It does not stop to consider the economic, social, or aesthetic value of something. It will burn whatever is in its path, as it has always done, and always will. Fire is nondiscriminatory, and thus, it can affect any and all of us.

Since World War II, wildland fire has become more relevant to all of us. After the war, dual trends emerged which have led to complex situations. People began to move out of urban areas and into suburban and semirural areas. Simultaneously, the country's population continued to grow rapidly, and more people began to set aside additional time for outdoor leisure activities. As a result, settlements in and the use of wildlands increased. Occupants often chose the area for its pristine environment, or for recreational purposes. The cost of living can be significantly lower than in urban areas, and thus can attract all economic classes. These factors have led to a unique problem, an area known as the wildland-urban interface, or I-Zone. A substantial human presence coexists uneasily with areas of fire-prone forest, brush, and grassland vegetation.

The interface is actually made up of three types of configurations. The "classic" interface is a result of urban sprawl. Homes and structures are placed in direct contact with wildland, and the inhabitants often have come directly from urban areas. The "intermix" interface occurs when single or clustered homes and other structures are scattered throughout a wildland area, e.g., summer homes, suburban homes on large tracts of land, and isolated recreation areas, such as cabins, mobile homes, and camping facilities. Many individual structures are often surrounded by woodland vegetation, and are served only by narrow roads, making it very difficult to reach these areas if fires occur. The "occluded" interface consists of islands of wildland within an urban area, such as a city park, or land considered unsuitable (e.g., too steep) for a structure. The threat of fire in these areas is low, but when fires break out here, there can be a substantial risk to surrounding structures and to those who use the natural areas.

Though the I-Zone problem is a national one, California was probably the first state to experience the phenomenon, and has endured several devastating fires. One extreme example occurred in October 1991, when wildland fire broke out in an urban Oakland park. It spread throughout an intermix area, and ignited much of the adjacent urban area. Twenty-five people were trapped and killed, and more than 3,000 homes were destroyed. Before that, in 1985, major wildland fires destroyed more than 1,400 homes and killed 44 people across the country, especially in the Southeast, New England, Idaho, Nevada, and central California.

Wildland-urban interface fires tend to be more damaging than urban structural fires, are often more difficult to control, and behave differently than structural fires. Interface areas are also likely to be increasingly flammable because of intensive suppression of fire cycles. Fires ignite indirectly in structures, and directly from accidental causes related to recreational and commercial use of the wildland. When these fires erupt, people and structures must take priority, often at a devastating expense to natural resources. People who live in these areas often come directly from urban areas, and may bring with them careless habits, and little understanding about wildland fire cycles and dangers. Homes and other structures are built and maintained in a manner which leaves them and their occupants vulnerable. Thus, fire becomes a significant threat to both humans and natural resources.

Another factor that contributes to the destructiveness of wildland fire is that structural firefighters are trained and equipped differently than wildland firefighters. Urban firefighters rely on the water systems provided in urban settings, and count on catching the fire in its early stages. Often, neither of these situations exists in the I-Zone. Wildland firefighters have no ready water supply except what they transport to the site. They also anticipate larger fires, and are thus trained to fight the fire from its perimeter, clearing fuel to prevent spread. Complications arise at interface fire.

There is considerable debate about who should take responsibility for this unique problem, and what can be done about it. Some believe that homeowners should take the most responsibility. In other words, some argue the risk-takers should pay for their decision to live in a potentially dangerous interface area, by paying more taxes and by taking precautions around their property. Realtors also have the responsibility to disclose the fire hazard possibilities. Designers and developers also need to take more responsibility. However, critics argue that making the necessary economic investments would be impossible for some residents, and others are unwilling to modify their home and surroundings for fear of compromising the rustic look.

Others assert that the whole community should take responsibility for the hazards. Property owners should be encouraged to make their own land fire resistant and defensible, and community governments should create, promote, and enforce fire-safety laws and adequate zoning codes. Community planners also need to understand and foresee how population growth, use patterns, and changing demographics will influence and contribute to the interface problem. Insurance companies should provide incentives and disincentives that encourage homeowners to take risk-reducing measures. Fire protection agencies should be more aggressive in effectively communicating the problem, consequences, and solutions of interface fires. However, critics fear that the community approach ignores the natural environment and its protection, and only concentrates on people and structures. There is also skepticism about getting all of the involved parties to work together.

Land management agencies have also been called upon to take a more active role in helping to control the problem by reducing fuel around interface areas regularly, so that fires are easier to manage and control. They may also rely on a prescribed fire regimen, but these carry some elements of risk. The concepts of "not in my backyard" and smoke impacts restrict options. In reality, residents must understand that fire and resulting smoke will occur on the site; the question is will it occur under a controlled, prescribed burn or as a conflagration. However, a regimen that involves both land management agencies and private landowners cooperating to maintain reduced fuel around structures could be much less destructive, more cost-efficient than suppressing fires, and much safer.

Though a comprehensive solution to the wildland-urban interface problem may not be immediately forthcoming, there are several simple and relatively inexpensive precautions the private homeowner can take to reduce the risk. The following are excellent talking/teaching points for the communicator.

Roofing

Homeowners should use alternatives such as asphalt, fiberglass, concrete tile, clay tile, or metal instead of wood shingles or shakes. Rain gutters should be cleaned regularly, as dead needles and leaves can be very flammable. Tree limbs should be cut back and cleaned away from the house, and the chimneys should be cleaned at least once a year.

Vegetation

To reduce fuels that could lead fire to the house, all dead lower branches should be cleared. Trees should be clustered so that there are gaps in the canopy (more difficult for fire to spread), and disturbed land grasses (those tall grasses introduced) should be cut within 30 feet of the house. Fire-resistant shrubs and vegetation should be planted, and combustible debris should be removed from under porches, decks, and crawl spaces.

Exterior Walls

Alternatives to wood siding, such as brick, stone, or metal are encouraged. These materials improve resistance to fire. If a homeowner already has wood siding, the amount of defensible space (space between the house and vegetation) should be increased to compensate. All crawl spaces and open areas under decks should be screened off.

Remote Location

If a home is located in a remote location, quick and open lane access for large fire apparatus should be provided for firefighters, and the address should be clearly posted so firefighters can find the house easily.

Slope

The steeper the slope, the more preparation is required. Wildfires readily burn up slopes and gullies as in "chimneys." The amount of defensible space should be increased as the steepness of the slope increases. Clearance alone is not enough, because wind can bring the fire to the house. The fuels should be reduced, but some plants should remain for slope stability. Also, a deck or wall built on the edge of the slope can deflect heat from the house.

Lack of Water

An independent water supply should be made available. Homeowners who install a cistern for water storage increase their chances of reducing fire damage.

Wildland fires always have and probably always will occur in most ecosystems. As people expand into these wildlands, the interface zone grows and so does the threat wildland fires pose to people and the threat people and their fires pose to wildlands.

References

Chase, R. 1993. "Protecting People and Resources from Wildfire: Conflict in the Interface." Culture, Conflict, and Communication in Wildland Urban Interface. Ewert, A. et al. (eds.).

"My Home–Making it safe from wildland fire."

Author: Colleen Labbe