Making Plans for Fire Suppression Activities

Fire planning takes place on several levels; for example to build and justify an annual budget request or to make sure that specific projects (e.g., mechanical thinning, prescribed burning, or both) are carried out as effectively as possible and at least cost compared to alternative treatments. The standards used in planning will vary depending on objective and scope. For example, for annual budget requests the minimization of cost plus net value change (damages net of benefits) has been the traditional goal for federal agencies. This goal recognizes the inevitability of wildfires, so the intent is to minimize their economic impact. So a budget is prepared for an entire fire management program, including activities such as initial attack and extended attack, fuels management, and fire prevention--with the hope of producing the lowest fire costs and damages throughout the upcoming fire season, an ambitious undertaking under any circumstances. 

 Planning for eventual suppression activities requires numerous considerations, including wildland vegetation, fire history, human population densities, weather and climate. Satellite imagery and computer modeling can be used to build data layers that depict wildfire risk, including those areas most likely to encounter damaging wildfires. Once high-risk areas are determined, fuels management, education and outreach efforts can be targeted to reduce consequences before future fires occur.

Wildfire risk assessment

The Wildland Fire Risk Assessment System is a planning system developed by Florida’s Division of Forestry. On a map, high hazard areas are color-coded red, while less prone areas are coded green. The system also can be used to allocate firefighting resources more effectively prior to or during a wildfire siege, by identifying areas most likely requiring emergency assistance. 

Many fire management agencies use principles similar to those in the Wildland Fire Risk Assessment System to develop pre-attack plans for individual management units, detailing advance tactics and necessary logistics. Maps are assembled that display

• fuel types
• recent burned areas
• road networks
• distances between different fire stations
• possible fire control lines
• helispots
• tractor loading areas
• fuelbreak and firebreak systems
• greenbelts
• water sources (artificial and natural)

Logical starting and end points for firelines are permanently signed on the ground. Signing enables the user to refer quickly from map to field notes, describing equipment and human resource requirements, and provides ground identification to field crews (Chandler and others 1983). Once assembled, these plans can be used with information on historic weather and climate and fire environment (e.g., wind, slope, and fuel moisture) to simulate potential fire outcomes or to develop programmed dispatch responses during the fire season.

Wildfire simulation models

Fire Behavior Chart

Numerous computer programs have been developed to aid decision makers, most of which to date are based on Rothermel (1972), with subsequent modifications. Computerized models such as BehavePlus and FARSITE provide estimates of fire behavior (rate of spread, flame length) that can be used to gauge suppression difficulty. NEXUS is a tool that uses a spreadsheet linking surface with crown fire behavior.  Flammap is a planning tool for tracing historic burn patterns on the landscape. Existing models for computing fire danger ratings can be used to produce a helpful tool known as a pocket card, from a program called FireFamily Plus, which provides incoming firefighters from distant locations with general guidance regarding expected local fire behavior. Fire behavior models allow the prediction of fire characteristics, such as surface fire’s rate of spread, fireline intensity, and flame length, which can be used to provide guidance for fire suppression activities, using a tool known as the fire characteristics chart, but are limited in terms of usefulness for predicting fire effects. These models also can be used to develop projections for the fire’s perimeter or area burned.

While models provide insight into fire spread phenomena, few models are able to incorporate all the important variables, including the impacts of fire suppression forces in controlling the growth of a spreading fire. Simplistic models have attempted to balance fire growth rates against the production rates of suppression crews, but fall short of incorporating the contributions of all firefighting resources (e.g., helicopters or airtankers).