Addressing Risk, Safety in Fire Containment

“The ecological, social and policy layers we consider aren’t exclusive to each other,” said Caggiano, also a CFRI researcher. “Fire is such a complex management issue and we are getting traction with this tool and planning framework because we are addressing the problem with the right amount of complexity.”

Early adopters of the POD framework include national forests in California and Arizona. CFRI and RMRS are working to bring the POD process and related decision support products to several landscapes in Colorado and the Intermountain West.

POD Size Could Protect Water Quality
Erosion from large and severe wildfires can harm water supplies, a finite resource in the west. In the second publication, Gannon led an effort to model the potential for an established Potential fire Operational Delineation network in Colorado to mitigate wildfire impacts on water quality by limiting fire sizes.

“We know fire size affects the severity of impacts for many resources, but we have only recently started to address it in wildfire risk assessment,” Gannon said. “Understanding how fire size affects water quality in different parts of the landscape can help managers tailor POD sizes to mitigate impacts.”

Gannon modeled how early wildfire containment within PODs could affect water quality at a municipal diversion in Colorado. The team’s results suggest that limiting fires to the POD of origin could reduce area burned by up to 59 percent and sediment loads from post-fire erosion by up to 55 percent. In contrast, limiting fire sizes with the current POD network is predicted to reduce the frequency of exceeding water quality thresholds for municipal water treatment by only 13 to 34 percent, depending on post-fire rainfall. Some PODs are not small enough to limit fire sizes below harmful levels.

This suggests that efforts to strategically divide high-risk PODs into smaller units are needed to achieve greater levels of protection.

Fire Line Effectiveness
Recent archiving of wildfire operations data provides the opportunity to examine how much fire line is constructed and how it contributes to fire containment. In the third publication, the team analyzed fire lines from 33 large wildfires that occurred in the western U.S. between 2017-2018 to quantify how much fire line burned over, held or did not engage with fires.

The proportion of fire line that engaged with fire and held averaged only 33 percent across the incidents studied. In some cases, fire burned over lines, but many incidents had large sections of fire line that did not engage with the fire.

Fire line performance varied widely across incidents due to an individual fire’s unanticipated growth or fire break placement. Fire line construction stood out in more populated areas. At times two to three times more fire line was constructed compared to final fire perimeters. In contrast, fire line production was only a small portion of the perimeter length for many fires in remote locations. This suggests that managers are adapting their strategies based on values at risk.

Gannon said the major value of the study is demonstrating how existing data can be used to monitor and rate fire suppression effectiveness to promote adaptive management in fire management organizations.

“This fire line performance evaluation framework provides a coarse filter to identify high and low performing fires,” he added. “A deeper dive is needed to diagnose the causes of inefficiencies and how to improve management strategies.”

As more detailed fire progression, behavior and suppression records become available, Gannon and other researchers will explore this topic to understand what fire line and environmental characteristics influence the probability of successful containment.

Researchers will use new data from the 2020 fire season in Colorado - which is proving to be severe and ongoing - to develop applied lines of research on wildfire risk and safety factors. The research team hopes to advance both fire science and its application in fire and land management to help with response preparations for future wildfires.