After assessing the exposure to wildfire of communities across the Pacific Northwest Region, Oregon and Washington, the 50 most-threatened communities in each state were identified.
In the broadest sense, wildfire exposure encompasses the likelihood of wildfire burning a given location on the landscape, and the potential intensity of a wildfire if one were to occur. For this assessment the researchers focused only on wildfire likelihood because the effect of fire intensity on home loss rate is not well studied, and because the inclusion of intensity for this and similar assessments did not influence the conclusions. Wildfire likelihood is measured by annual burn probability, a measure generated by comprehensive simulation of wildfire occurrence and spread (see section below on Wildfire hazard simulations).
The 10 communities in Washington with greatest cumulative housing-unit exposure to wildfire. The “mean of exposed housing units” rank indicates the mean (typical) burn probability of housing units within each community.The 10 communities in Oregon with greatest cumulative housing-unit exposure to wildfire. The “mean of exposed housing units” rank indicates the mean (typical) burn probability of housing units within each community.
The research was commissioned by the U.S. Forest Service’s Northwest Region.
More details, including lists of the 50 most threatened communities in both Oregon and Washington, can be found here.
Therefore, prescribed fires to protect communities can protect residents in more ways than one
Prescribed fire at Wolf Trap National Park, April, 2018. NPS photo by Nathan King.
Researchers studying the effects of smoke on children found prescribed fire smoke to be less harmful than smoke from wildfires. The Stanford University study looked at three groups of children:
Those who were exposed to smoke from a prescribed fire;
Children exposed to smoke from a wildfire in which no structures burned; and,
Children that were not exposed to smoke.
Sometimes fire personnel refer to a prescribed fire as “good fire”. Now they may call smoke from a planned burn as “good smoke”. A way to look at this research is that removing hazardous fuels near a community is a way to reduce the threat of a wildfire spreading into the town and burning structures or entrapping and killing people. And, removing the fuels with good fire rather than allowing a wildfire to burn the same area, exposes residents to less harmful smoke. For fire-prone areas, it is not IF it burns, it’s WHEN. Do you want your smoke now under controlled conditions or later, possibly under extreme conditions?
From Stanford University:
…The study was published May 30 in the European Journal of Allergy and Clinical Immunology. It was conducted in Fresno, California, a city with high air pollution levels due to its topography and other sources, including traffic and agriculture.
“This study suggests that exposure to wildfire smoke is detrimental above and beyond poor air quality,” said the lead author, Mary Prunicki, MD, PhD, an instructor of medicine.
The study’s senior author is Kari Nadeau, MD, PhD, professor of medicine and of pediatrics and director of the Sean N. Parker Center for Allergy & Asthma Research at Stanford.
Native Americans traditionally used controlled burns to manage California’s forests, but throughout the early 20thcentury, wildfires were widely suppressed. This began to change in the 1960s and 1970s, when scientists recognized fire as a normal part of forest ecology. Recent wildfires have brought more attention to the possible benefits of prescribed burns as a way to reduce fuel levels and wildfire risk, but not everyone is enthusiastic.
Opposition to controlled burns
“We know that there’s some public opposition to doing prescribed burning,” Prunicki said. “It’s our feeling that prescribed burning, because it’s so controlled, may expose people to fewer health effects than wildfires.” Prescribed burns are of lower intensity and are permitted only when weather conditions allow the fire to be contained.
In the study, the researchers compared blood samples from three groups of children, all of whom were 7 or 8 years old. One group of 32 children had been exposed to smoke from a 553-acre prescribed burn that occurred in March 2015; a second group of 36 children had been exposed to smoke from a 415-acre wildfire in September 2015. Both fires were about 70 miles away from Fresno, and blood samples were collected from the children within three months of each fire.
The study also included blood samples from a control group of 18 children who lived in the San Francisco Bay Area and had not been exposed to wildfire or prescribed-burn smoke.
The researchers measured air pollution levels recorded at four monitoring stations in Fresno and estimated pollution levels at the children’s homes during the fires based on how far they lived from the stations.
Pollutant exposures were higher in the wildfire group compared to the prescribed-burn group. The air pollutants measured included nitrogen dioxide, polycyclic aromatic hydrocarbons, elemental carbon, carbon monoxide and particulate matter.
Wildfire smoke exposure was associated with lower blood levels of type-1 T helper cells, a group of immune cells that are involved in the immune response. Among children exposed to wildfire smoke, the researchers also saw increased methylation of the Foxp3 gene, indicating reduced activity of this gene, which is broadly involved in modulating allergic and other immune responses. The finding of greater Foxp3 methylation is congruent with earlier studies of the effects of air pollution on the immune system, Prunicki noted.
Significance of particulate matter
One important aspect of the study was that the September 2015 wildfire was confined to forested areas and did not burn any structures.
“Particulate matter from wildfires is different from region to region and depends on what is burning,” Prunicki said. “When a wildfire is going through a town, there are a lot of concerns about what happens to the chemicals in people’s homes and cars when they go up in flames.” Smoke from wildfires that burn inhabited areas almost certainly has worse health effects than those found in the current study, she said.
The researchers plan to conduct larger, more detailed studies of the effects of wildfire smoke on health. They will be enrolling healthy people in a trial at Stanford later this summer to collect baseline data from blood samples. When future wildfires affect Bay Area air quality, the participants will be asked to provide follow-up blood samples.
The scientists also plan to research the health effects of using home air purifiers during wildfires, as well as measure the protection offered by N95 masks, with the aim of developing recommendations for when masks should be used by different populations, such as healthy adults, elderly people, children and people with chronic illnesses.
The study’s other Stanford co-authors are biostatistician Justin Lee; life science researcher Xiaoying Zhou, PhD; Francois Haddad, MD, clinical associate professor of medicine; and Joseph Wu, MD, PhD, professor of medicine and of radiology.
Combining aerial and terrestrial LIDAR data with new 3D field sampling
By Diane Banegas, Research and Development, U.S. Forest Service
Land managers have a new tool in their firefighting arsenals that models forest fuels in three dimensions. These 3D fuel models have the potential to make firefighting and the management of controlled burns safer and less costly while helping to protect valuable natural resources.
The 3D fuels modeling technique will benefit land managers by allowing firefighters to develop better strategies and helping predict future fire behavior. It was recently tested at Eglin Air Force Base in Florida.
New 3D fuel modeling techniques help land managers predict future fire behavior. Here, Louise Loudermilk (right) and Christie Hawley (left) collect 3D fuels in the field. Photo courtesy: Susan Prichard, University of Washington.
Managers will be able to input 3D fuels from this research into next-generation fire behavior models. This will allow them to test different ignition patterns for a prescribed burn to see how the resulting fire behaves in 3D.
Running 3D simulations can help firefighting teams develop strategies to manage or extinguish future fires as safely and economically as possible.
“These fire models can output various scenarios of fire behavior that help inform quick management decision making,” said Louise Loudermilk, a research ecologist at the USDA Forest Service’s Southern Research Station. The model can also give “burn bosses” choices on selecting the safest approach to meet management and ecological controlled burning objectives while better predicting smoke conditions.
“This work represents a new era in fuels research because it links fuel ecology with fire behavior. In fire behavior models, fuels traditionally are overgeneralized and have been unable to represent how fuels predict fire behavior. Now fuels can be represented dynamically in three dimensions,” Loudermilk said. “This advancement, which has taken over 10 years to achieve, is like going from a board game to a realistic video game.”
Louise Loudermilk ignited a prescribed fire with a drip torch for management and ecological objectives. A new 3D fuel model can help make the management of controlled burns safer and less costly. USDA Forest Service photo by Christie Hawley.
The modeling technique combines aerial and terrestrial LIDAR data with new 3D field sampling, historical data about when an area last burned and simulation modeling to provide 3D fuel characterization at multiple scales. Data collected from a landscape of interest includes vegetation type, fuel mass and fuel volume, all represented in 3D.
Loudermilk co-authored a research paper about a new method of field sampling used for this modeling technique. “The method works equally well across small or large landscapes,” she said. “Our goal is to provide big data collections that will one day be downloadable for anyone to use.” She also contributed to a book chapter about the 3D modeling technique and the importance of fuels research. A related paper in Forest Ecology and Management explains how the status and trends of plant diversity can be monitored at a landscape-scale, information valuable for 3D fuels monitoring.
Ultimately, extensive 3D data collected on fuels will be available for landscapes across the United States. Any land manager will be able to select the data for their area and run 3D fire simulations for educational or fire management purposes.
The success of these projects has been dependent on Loudermilk’s extensive network of federal, state and private organization collaborator
Output from processing of terrestrial laser scanning data, representing an important fuel characteristic “surface area” as illustrated by the different colors. This is input to next-generation fire behavior models. Image courtesy Eric Rowell, Tall Timbers Research Station.
After a couple of days of decreasing wildfire smoke from Canada, on Tuesday the United States midwest is seeing heavier concentrations of the pollutant generated by fires in Alberta.
Firefighters, heavy equipment, and aircraft continue to work on the McMillan Complex in Alberta which is approximately 22km northeast of the junction of Highway 88 and Highway 754. The complex is comprised of 4 wildfires that are a combined 215,065 hectares (531,439 acres) in size. Alberta Fire photo.
At least five hotshot crews from Oregon and Montana will be leaving Wednesday to assist with the wildfires in Alberta.
Kathy Bushnell of the Helena-Lewis and Clark National Forest said Montana hotshot crews from the Helena, Lolo, Bitterroot and Flathead national forests will travel north with the Rogue River Hotshots from Oregon.
Deb Schweizer of the USFS office in Boise told Wildfire Today that an additional 15 personnel are being mobilized for a variety of overhead positions.
Thanks and a tip of the hat go out to Tom. Typos or errors, report them HERE.
The distribution of wildfire smoke at 8:11 a.m. MDT June 2, 2019. NOAA, Office of Satellite And Product Operations.
Smoke from wildfires in Alberta is still detectable across most of the Eastern United States today, but the Canadian government’s smoke forecast expects a significant decrease throughout the lower 48 states on Monday.
Cooler weather along with a slight chance of showers off and on in Alberta over the last several days has slowed the progress of the wildfires, including the 230,000-hectare (568,000-acre) Chuckegg Creek Fire at the town of High Level. Those conditions are expected to continue during this week, so it appears that U.S. residents will get a respite from polluted air that at times has been very unpleasant in the Northwest, especially along the Canadian border in Montana and Idaho.
The map above represents conditions today, Sunday June 2. The map below is the Canadian government’s forecast for smoke tomorrow, June 3. The Canadian system does not predict smoke conditions in the south half of the U.S. (outside of the box with the black lines).
The smoke forecast for Monday at 5 a.m. MDT June 3, produced by the Canadian government.
