The Science of Mapping WildFire Hazard

What is the Science of Mapping?

Wildland fire is a serious concern for community members in the wildland-urban interface (WUI), the area outside of urban districts where human development is mixed with wildlands.

While defining the WUI in any given area can be a difficult task, a Geographic Information System (GIS—a computer-based mapping and spatial analysis interface), can be an effective tool to analyze, model, determine, and mitigate hazards and risks related to the WUI. Spatial analysis is crucial for management of land, resources, and public safety. GIS is the most efficient way to accomplish these tasks and has been well integrated into managing risks within the WUI in many areas of the western United States. As the risks grow on a local as well as national scale, research and resources are continually devoted to the capabilities of GIS for WUI management.

How can GIS reduce WUI hazards?

Determine Risks: By examining multiple sets of data, hazard and risk can be determined from a variety of perspectives.

Provide Tools for Firefighting: Hazard assessment can reduce wildfire risk and aid in managing a wildfire event by mapping resources and dangerous areas.

Produce Maps and Communication Tools: By providing a visual point of reference for analysis, maps can increase communication throughout the community.

What Can GIS Assess?

GIS and fire experts find there are three types of geographic data that are most useful for determining wildfire risk in a given area:

Topography and Dominant Vegetation (“fuels”):

Image: Wildfire Atlas, Chris DeSisto and Dwight Berry

These data sets include two of the most important factors driving wildfire behavior—slope and vegetative fuel loading.

Weather: Regional and microclimate variations can strongly influence wildfire behavior. Because of unique geographic features, weather can vary from one neighborhood to another, leading to very different wildfire behavior.

Asset Location:

Image: Wildfire Atlas, Chris DeSisto and Dwight Berry

A spatial inventory of assets—including homes, roads, fire stations, and natural resources that have needs for protection—in relation to wildfire hazard helps prioritize protection and mitigation efforts.

These data sets are combined using standard methods in geographic information science. The results of this process can then be used to determine what parts of the Peninsula have the highest wildfire hazard, where our WUI is located, and which communities would face the highest risk of catastrophic loss in the event of major wildfire occurring on the Peninsula.

How Can GIS Assessment Reduce Wildfire Risk?

We can take advantage of advances in GIS and fire science to reduce the wildfire risk in our communities and neighborhoods without adversely affecting the ecology and environment we associate with our high quality of life. Some of the most effective efforts that result from GIS hazard assessment include:

Fuel reduction programs at the neighborhood/residential level can reduce the ignitability of targeted personal and community assets.
Prescribed burns and/or forest thinning projects can be delineated and more effectively planned and managed with GIS information.
Design, creation, and maintenance of shaded fuel breaks in WUI zones, which reduce the potential for natural vegetation to burn, provide firefighters with established aids in fire fighting.
Progress on a variety of public safety and land management programs can be tracked and continuously updated using a GIS to assist public safety officials and policy makers with up-to-date planning and emergency operations support.

Many other programs can be developed based on specific needs of the community; for example, GIS can also be used to help determine costs and/or explore the pros and cons of different project alternatives. Overall, though, these costs can be offset by the reduced costs of fighting fire within the WUI that come with risk reduction—in effect, these efforts are fighting fire before a fire even starts.