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Suppression Difficulty Index

Suppression Difficulty Index on the Crescent Mountain Fire. Red and orange areas are highest suppression difficulty (more extreme potential fire behavior and/or difficult access), blue areas depict locations with reduced suppression difficulty.
Suppression Difficulty Index on the Crescent Mountain Fire. Red and orange areas are highest suppression difficulty (more extreme potential fire behavior and/or difficult access), blue areas depict locations with reduced suppression difficulty.
Firefighting is an inherently hazardous occupation and responder safety is the primary concern on all incidents. Researchers from the Wildfire Risk Management Science Team are collaborating with fire scientists in Spain and Oregon State University as well as wildfire operations specialists to develop and apply spatial tools that weigh the potential hazards of fire against our ability to position people and resources where they are likely to be effective. 

This Suppression Difficulty Index (SDI) provides a spatial summary of “watch out” situations as well as areas with reduced risk to fire responders that can be used to facilitate strategic and tactical fire management decisions. While much of this information is intuitive to firefighters on the ground, the spatial overlay can also be used to help with strategic decision making. 

SDI is part of the potential control locations model but can also be used as a stand-alone product. During incident support, SDI can be produced in real-time using spot weather forecasts to identify dynamic changes to fire responder exposure. 

The current generation of SDI does not directly address snag hazards or smoke and heat exposure, however, researchers are currently working on ways to integrate these additional hazards into the index.

Wildfire Suppression Difficulty Index (terrestrial) (SDIt) is a quantitative rating of relative difficulty in performing fire control work. In its original formulation for use in Spain, SDI included aerial resource use, however for development and application in the United States we removed the aerial resource component due to a lack of consistent data. We note this distinction of “terrestrial only” calculations with the inclusion of “t” in the acronym. SDIt factors in topography, fuels, expected fire behavior under severe fire weather conditions, firefighter line production rates in various fuel types, and accessibility (distance from roads/trails) to assess relative suppression effort. For this dataset severe fire behavior is modeled with 15 mph up-slope winds and fully cured fuels. SDI has a continuous value distribution from 1-10. Here it is binned to six classes from lowest to highest difficulty.

Check out the interactive map below or view the data here.