Modelling Wildfire Threats

CalFIRE's most recent figures estimate approximately 12 million homes on 8 million acres in the state's Wildland Urban Interface (WUI). Wildfires will always be with us, but there's hope for mitigating their destruction beyond throwing more firefighters and equipment at the problem.

Urban foresters can use GIS (geographical information system) to identify problem areas and recommend corrective action by modeling fire behavior.

Software programs like FlamMap and FARSITE take into account weather, terrain and available fuels to calculate flame lengths, fire spread rate and generated heat. Wildfire specialists use the information to identify hazard areas, fuel treatment priorities, and fuel modification zones.

In 2006, the City of Del Mar Fire Department used GIS modeling software for high-risk zones in residential canyons with thick brush. They removed hazardous fuels and provided firefighters with “defensible space” to more effectively control a fire’s spread - while retaining soil integrity and without doing ugly, wholesale chopping of foliage.

Wildfire specialists say GIS modelling can help fire agencies:

• Prioritize efforts based upon known hazards, and conduct pre- and post-treatment analyses to determine the fuel modifications predicted success.
• Analyze where new buildings should be sited as well as how structural requirements will help reduce the vulnerability to wildfire.
• Plan for fuel modification based on modeled fire behavior in vegetation communities and design setback requirements.
• Treat areas strategically to minimize impacts to sensitive habitats while maximizing reduction of fire intensity.