As thousands of firefighters battle huge wildfires in the Southwestern U.S this week, some are using a new tool in their kit: a computerized model that calculates the fire risk in real time — drawing on data about the fire’s behavior, danger, moisture over the past several decades, and terrain topology — to swiftly produce a priority map for where firefighters are most needed.

Severe fire seasons of the past decade in the western United States have spurred many government agencies to manage lands to reduce fire intensity and severity to ultimately protect human life and property.

 

However, seven decades of fire exclusion policies have resulted in the dense forest canopies, high surface fuel accumulations, and increased fuel continuity across large regions where fires were historically frequent. These abnormal fuel conditions may foster abnormally severe wildfires that are projected to increase with global warming. The western U.S. has also experienced a marked increase in human development in areas surrounding public wildlands thereby creating and expanding a “wildland urban interface.” With this expansion comes an increased risk to human life and property as severe wildfires become increasingly common. In response, federal agencies have advocated fuels reduction treatments to mitigate the risk and hazard of severe wildfires, particularly in the wildland urban interface. With limited available funding and the cost of fuel treatments continually increasing, fire managers have been charged with developing a detailed methodology for identifying and prioritizing which federal lands are in the greatest need for fuels reduction treatments. A quantification of fire hazard and risk is critical for identifying and prioritizing areas for fuel fuels treatments, and comprehensive fire models are an important first step towards providing spatially explicit estimates of fire risk and hazard over a range of spatial and temporal scales.

 

This project involves the development of a research computer model called FIREHARM (FIRE HAzard and Risk Model) that computes common measures of fire behavior, fire danger, and fire effects over space to use as variables to portray fire hazard spatially, and then computes fire risk by simulating daily fuel moistures over 18 years to compute fire measures over time. The digital hazard and risk maps can then be used for fire management planning and real-time wildfire operations. Extensive validation of six FIREHARM output variables is being conducted to estimate model accuracy and precision to aid in the interpretation of results.

Read more about the FIREHARM project — which is funded by the U.S. Department of Agriculture and the Joint Fire Science Program — at the Fire Sciences Lab.

And check out a recent article in The New York Times.

(Contributed by Max Cho, Eben Tisdale Fellow, CRA)