Computer modeling can help prescribed burning decisions

Prescribed burns can be a key weapon in preventing catastrophic wildfires, but finding the right window to burn can be difficult, and with dry conditions, prescribed burning in New Mexico has come to a standstill. A modeling effort by scientists at Los Alamos National Laboratory aims to provide agencies with a tool to determine when conditions are best for burning.

Rod Linn, a Los Alamos scientist who leads the wildfire modeling team, said NM Policy Report Various factors are used to determine when it is safe to burn, but conditions can change quickly.

Gov. Michelle Lujan Grisham told a briefing on Saturday that the state is banning campfires on pit grounds and asking every local government to consider ways to ban the sale of fireworks. It comes as 20 wildfires were actively burning Saturday afternoon across 16 counties in New Mexico.

“Half the state has a fire problem,” she said.

She said high winds, dry fuels and low humidity contributed to the fire danger. More than 25,760 acres burned Friday.

The Hermits Peak Fire that started April 6 near Las Vegas, New Mexico is an example of a prescribed burn spiraling out of control. The US Forest Service declined to comment on the Hermits Peak Fire and what led to the spread of several spot fires. The Hermits Peak Fire has since joined forces with the Calf Canyon Fire and together they have charred over 56,000 acres and caused evacuations in San Miguel and Mora counties. The agency said the fire was still under investigation.

The Calf Canyon fire, which joined the Hermit Peak fire, is the main concern, according to Lujan Grisham. She said the number of structures the fires have destroyed remains unknown.

The causes of most fires in the state, including the Calf Canyon fire, are still under investigation, Lujan Grisham said.

She acknowledged the importance of prescribed burning and said prescribed fires “will always be a tool, they have to be particularly in areas where you can’t enter productively.”

She said she hopes fire managers will reevaluate when they do prescribed burns and in which areas.

State Forester Laura McCarthy said during the briefing that there may be a window for prescribed burning this fall, but there will likely be no more prescribed burning this spring.

Linn said the national lab has been studying wildfires for decades, however, over the past seven or eight years, Los Alamos has begun working closely with various partners, including the Forest Service, to model the behavior of prescribed burns. The model they are working on is known as QUIC-Fire. Work on the software has been going on for several years.

“We recognized there was a shift in the way people think about fire and in particular we are talking about fire in a more proactive way,” Linn said.

Preparing for a prescribed burn

He said methods of manually reducing fuel loads on landscapes, such as cutting trees and clearing brush, can be costly per acre.

Linn said fire is an inevitable part of the ecosystem.

“We’re not going to be able to avoid having the landscape on fire,” Linn said. “As a country, we have tried to keep fire out of the landscape for over a century.”

He said efforts to rule out fires have resulted in unhealthy forests, in many cases, and often increase the risk of catastrophic wildfires.

“Fire is a natural ecosystem disturbance that removes dead, fluffy woody material from the forest floor, helps thin dead branches from the crowns of lower trees, and reintroduces nutrients to the soil,” Punky Moore said. , Forest Service fire communications specialist, in an email to NM policy report.

Moore said mechanical treatments can remove small trees and underbrush but, most of the time, don’t deal with large logs and fallen trees or forest litter on the ground.

“The directed fire creates a mosaic pattern as it burns through the unit,” Moore said. “Rarely does a prescribed fire burn as intensely as a wildfire under extreme conditions. Due to the less damaging effects of fire, prescribed fires will leave patches of unburned landscape that will benefit small mammals, insects and predators that depend on them.

In contrast, she said mechanical clearing generally results in uniform treatment across the landscape. This can impact larger animals that depend on wooded areas for shelter.
“Mechanical treatments are beneficial and reduce the risk of forest fires; however, they cannot match the benefits that prescribed burning brings to the landscape,” Moore said.

But controlled burns are also complicated and require lots of assessments to make sure the conditions are right, Linn said.

The Forest Service begins planning prescribed burns years before the first kindlings are ignited, according to information provided by Moore NM policy report. This process involves analyzing the landscape for prescribed fire treatments and the effects that burning might have on vegetation, hydrology, threatened and endangered species, and humans living nearby. Punky said the National Environmental Policy Act process occurs before prescribed burns.

Once the initial analysis is complete, a “finer scale” analysis of the landscape is carried out. During this analysis, prescribed burn units are drawn on maps and in spatial geographic information system programs, Moore explained.

“Fire managers take the proposed boundaries and walk the area to document potential hazards, containment characteristics, vegetation composition, fuel load of dead material on the ground, general forest health, and much more. Moreover. Fire officials then adjust boundaries, discuss with other specialists, and move the concept into a five-year plan,” she wrote in the email.

The five-year plan includes all proposed projects that the Forest Service explores or plans to implement during the five-year period in that area. Moore said this approach helps the fire manager see the big picture and see how individual prescribed burns can fit together or affect each other to maintain healthy ecosystems. This plan is reviewed annually and may be adjusted based on priorities, funding or seasonal conditions.

A few years before a prescribed burn is ignited, the Forest Service has the area inspected by specialists. These specialists search for threatened and endangered species and archaeological sites. Moore said the results of these surveys are incorporated into future prescribed fire plans.

Prior to the burn, fire managers assess various conditions. Moore said there is a model prescribed fire plan that includes 21 items that need to be addressed. Some of these elements include desired weather conditions, fire behavior, communications planning, smoke management, and post-treatment monitoring. Preparations also include modeling the expected fire behavior inside and outside the unit.

A separate document known as the Complexity Analysis Spreadsheet is also completed prior to burning. Moore said it looked at things like pre-plan risk and post-plan risk as well as technical difficulties.

After that, another qualified burn manager reviews the prescribed burn plan, including reviewing each item.

If the reviewer agrees with the plan and determines that it is sound, it can be submitted for final approval. Moore said an administrator from the Forest Service agency then reviews all parts of the documentation. If this administrator accepts it, the plan is approved and an engraving manager is assigned to the project.

She said the burn official is working with the National Weather Service to monitor long- and short-term weather conditions leading up to the prescribed burn. Prior to the start of the project, fuel moisture readings are taken. These readings come from both live and dead plants in the intended area.

The National Weather Service provides the burn manager with site-specific forecasts for each day the prescribed burn is expected to occur. Moore said firefighters on the ground will also monitor weather conditions and provide information to the National Weather Service.

Linn said few prescribed burns get out of control like the Hermits Peak Fire.

Modeling efforts

Linn said the model looks at things like ignition methods. He explained that when prescribed burns are lit, they are not just in one place. Teams can manage the intensity of the fire by illuminating different points of the landscape.

“One of the most important things we’re looking at is modeling fire behavior by reacting appropriately under different ignition patterns or different conditions,” Linn said.

Linn said this model is not complete and adjustments are still being made, but Los Alamos is happy with the results when the model has been used in places like California.

As the western United States faces drought and aridification, the time when prescribed burns can safely take place is changing, Linn said. He said the time window in which land managers can burn can change from year to year depending on factors such as differences in snowfall.

Additionally, Los Alamos has partnered with the US Geological Survey to produce computer models to predict wildfire behavior under different scenarios. This partnership became official this month with the signing of a memorandum of understanding last week.

A press release announcing the memorandum of understanding said the templates help managers plan prescribed burns, including when and where they should be lit. The models also help land managers understand and predict the direction in which a fire will move and its intensity.

The press release indicates that current fire models have limitations.

“This partnership leverages USGS expertise in 3D terrain and vegetation mapping to support the application of Los Alamos National Laboratory’s suite of advanced fire modeling tools and will provide a scientific support for research communities and fire managers, who will increasingly rely on more sophisticated tools. understanding of fire behavior to address new fire behavior in a changing climate,” said Anne Kinsinger, USGS Associate Director for Ecosystems, in a press release.

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