U.S. Senators John McCain and Jeff Flake, both representing Arizona, spoke to residents in Show Low and Pinetop-Lakeside March 24. According to an article in the Arizona Journal, Senator McCan discussed the importance of thinning forests in the state, in part to prevent trees from exploding. Here is an excerpt from the article:
“In the State of Arizona, and in Navajo County, the future rests on two issues to a large degree, and that’s fire and water,” said Sen. McCain, relating the statistic that 20 percent of U.S. national forests have been consumed by fire in the past 15 years.
McCain noted that the issue of forest thinning has been given top priority by officials at the nation’s capitol. “Unless we thin these forests, we are going to see the kinds of things that we saw with the Chedeski fire and the Walleye fire, and that is trees literally exploding as the fuels that have accumulated around the bases of the trees burns up,” he predicted.
“Without forest thinning, fires will just sweep right through,” he said, also pointing out the ‘snowball’ effect that forested areas decimated by fire also become susceptible to chronic ground surface water runoff, which worsens drought conditions.
Having been a wildland firefighter for 33 years, as far as I know trees exploding in wildland fires is a myth. I’ve never seen it, heard it, or talked to anyone who has witnessed such an event. This has been perpetuated in a number of books and articles, but I have never seen the evidence.
When lightning strikes a tree it can explode when the moisture inside is converted to steam in a millisecond. And maple trees can explode in below freezing temperatures when the sap freezes. There are unconfirmed reports that eucalyptus trees in Australia can explode in a fire but I’m not convinced this is true. I understand that heated gasses or sap can shoot out of a crack in a eucalyptus tree and can be ignited during a fire. Maybe some of our Australian friends can provide more accurate information.
Homestead National Monument expects to ignite a prescribed fire using an unmanned aerial system, or drone.
Above: University of Nebraska-Lincoln researchers Dirac Twidwell, left, Sebastian Elbaum, and Carrick Detweiler with their unmanned aerial system for supporting prescribed burns. Elbaum and Detweiler are professor and assistant professor of computer science and engineering, respectively. Twidwell is an assistant professor and rangeland ecologist in UNL’s School of Natural Resources. Photo by Craig Chandler / University Communications.
The prescribed fire at Homestead National Monument four miles west of Beatrice, Nebraska will include a live test of a University of Nebraska-Lincoln (UNL) small Unmanned Aircraft System (sUAS). The UNL system is a greatly scaled down version of a manned helicopter aerial ignition device. A multidisciplinary team of UNL experts in micro-UAS technology, fire ecology, conservation and public policy is developing this unmanned aerial system for supporting prescribed and wildland fire operations. We first wrote about their fire-igniting drone at Fire Aviation in October, 2015.
The park has received all of the approvals necessary to use the drone on this project, including the NPS Regional Office, their Washington office, and the Federal Aviation Administration.
Jim Traub, National Park Service (NPS) Unmanned Aircraft System Specialist, said:
UAS’s in firefighting have the potential to reduce direct risk to firefighters doing ignition work while reducing costs and making an aerial resource more widely accessible to wildland firefighting efforts. The National Park Service is pleased to facilitate this unique and innovative opportunity with UNL, for this test of a sUAS in a fire situation.
Homestead National Monument of America, the NPS Midwest Region Fire and Aviation Program, and the NPS National Aviation Offices are collaborating with UNL’s Nebraska Intelligent Mobile Unmanned Systems (NIMBUS) Laboratory and the Department of Interior Office of Aviation Services (OAS) for this operational test and evaluation of the integration of sUAS into wildland fire operations. The goal with the Homestead Prescribed Fire is to conduct a live test of the sUAS consistent with the intent of 2015 UAS Technology Overview approved by then NPS Associate Director of Visitor Resource Protection, Cam Sholly; Department of Interior Deputy Assistant Secretary, Kim Thorsen; and Office of Aviation Services, Director Mark Bathrick.
Their system uses the same principle for the ignition source as the much larger devices used in full sized helicopters — plastic sphere dispensers. The spheres look like ping pong balls, but they are manufactured with a chemical inside. When the dispenser injects a second chemical into the ball it creates an exothermic reaction causing it to burst into flame about half a minute later after it has been ejected from the machine. When the helicopter, manned or unmanned, drops the spheres, they can ignite any receptive fuels on the ground about 25 to 40 seconds later.
Now that Homestead National Monument has all of the plans and approvals in hand, they are just waiting for a weather window that meets the criteria in their prescribed fire plan. They hope to get it done before May 15 of this year.
I asked the park Superintendent, Mark Engler, if he was worried that the drone might drop a sphere outside the prepared control lines:
No, I know we have to be alert that that could happen, but we have already put in a fireline, and we made it extra wide this time. We took an extra step and actually removed the cut grass [from the line after it was mowed]. We think the risk here is very low. And because the risk is so low, we feel that this is an appropriate place to conduct this test.
A control line for a prescribed fire at Homestead, spring, 2016. NPS photo.
The park has been using fire for years to help maintain and restore their tall grass prairie. They have identified a 26-acre unit for this particular project. Homestead first started using prescribed fire in the 1980s. Mr. Engler said they have the “oldest restored prairie in the National Park Service”.
The plans call for 15 people to be actively involved in the burn, plus the crew operating the unmanned aerial system.
The University of Wyoming has issued a publication about the patterns, influences, and effects of wildland fire in the state.
The University of Wyoming paper covers basic facts about fire, weather, intensity, severity, prescribed burning, as well as fire effects and interactions with soils, plants, livestock, wildlife, and bark beetle outbreaks. The document is 16 pages long with an additional 8 pages of references and a glossary. It was written by Derek Scasta, Assistant Professor and Extension Rangeland Specialist.
A couple of items attracted my attention. One is the graphic at the top of this article, the mean fire return interval for Wyoming. If you’re familiar with the geography of an area, data like this can absorb your interest for a while. The map appears to be a section taken out of the whole country map.
Another topic covered in the publication is the relationship between precipitation and acres burned.
The chart above from the paper uses the total Wyoming statewide annual precipitation compared with the total number of acres burned in wildfires each year. We have been thinking that the weather in the summer has a greater effect on acres burned than weather throughout the year. Those weather factors include temperature, relative humidity, wind, and precipitation, and a few others used by the National Fire Danger Rating System. It’s beyond our capacity to analyze all of those, unless we use an index that takes multiple parameters into account, such as the Burning Index or the Energy Release Component.
But what we did (immediately above) was to take one weather parameter from the summer and plotted it on a chart similar to the UofW chart– average monthly precipitation each year for June, July, and August. The weather data came from NOAA, and the acres burned was extracted from the University of Wyoming chart.
Included among the disclaimers is that average precipitation across the state does not apply to every square mile. Thunderstorms in the summer could be hammering one area, while a major fire is burning somewhere else. And, using only precipitation does not take into account temperature, relative humidity, and wind, which are all very important.
If anyone is interested in analyzing the Wyoming fire occurrence data using another weather factor or NFDRS Index (from the summer months), below are the numbers I used. Or, if you’d like to look at another state or geographic area, that would be fine. It’s important to analyze the acres burned and the weather observations for a large area in order get a sample of sufficient size to make it statistically significant. For example, use 15 to 20 years of information from a large national forest with multiple weather stations to reduce the data-skewing impact of a gully-washer thunderstorm at one location.
While most areas in the western United States, with the exception of parts of Arizona, New Mexico, and Texas, wait for their fuels and weather to dry out, many firefighters in the east have been busy lately. The Intelligence section at the National Interagency Fire Center is too busy this time of the year to issue a daily Situation Report, so we assembled information about a number of fires east of the Mississippi River.
Tennessee
A prescribed fire conducted by the Tennessee Wildlife Resources Agency (TWRA) that got out of control in Blount County on Wednesday has burned 400 to 500 acres as of Thursday morning. TWRA officials said the wind picked up unexpectedly while they were treating a unit in the Foothills Wildlife Management area.
A fire in the Cherokee National Forest has burned 150 acres six miles north of Unicoi. Additional aircraft, dozers, engines, and firefighters have been ordered. (The tweet below is about this fire.)
North Carolina
Mike Martin’s brush pile he was burning behind his house Wednesday near Etowah escaped as winds blew flames onto his porch. He went to grab two five-gallon buckets of water, but by the time he returned it was too late. He tried to go into the house to retrieve his car keys, but the fire was too hot. Both the Ford SUV and the house were destroyed even though the fire department responded quickly from their station two miles away.
A fire in the Nature Conservancy’s Nags Head Woods Preserve blackened about 250 acres on the Outer Banks. It started on March 22 and spread for three days.
New Jersey
A wind-driven brush fire burned 86 acres in Port Republic Wednesday afternoon. With help from two water-dropping helicopters, about 30 firefighters stopped the spread.
Frequent and effective communication between response organizations and individuals is critical to ensuring the most effective response during wildfire incidents.
Above: Incident Command Post at the Eiler Fire, August 8, 2014 at Anderson, California. Photo by Bill Gabbert.
Most of the detailed reports I have seen about critical incidents identified communication as an area that needed improvement.
In a recent study, researchers analyzed the influence of pre-incident familiarity, stakeholder affiliation, and primary wildfire response/functional role on communication frequency and efficacy during three western U.S. wildfires ignited on U.S. Forest Service land. All fires occurred in wildland/urban interface areas, and involved a range of parties including Type 1 Incident Management Team response teams, local forest leaders, and responding agencies.
“…Since wildfires are one of the most common disasters faced by communities in the U.S., understanding factors contributing to effective disaster response is key to improving response efforts. Effectiveness of disaster response is strongly impacted by the effectiveness of communication between individual responders during the incident. This research shows that mechanisms that establish relationships between disaster responders prior to wildfire incidents may increase communication between responders during wildfire incidents, and thus, reduce problematic communication and increase the effectiveness of disaster response.
Pre-incident relationship building may serve to strengthen understanding and increase mutual trust between responders. This suggests that community efforts to increase social contact between responders prior to incident can lead to benefits during disaster events by increasing the frequency and effectiveness of communication between individual responders.
This research also suggests that it can be problematic to assume that individuals with shared institutional roles will have more effective communication.
The least effective communication reported in this study was between individuals with similar institutional roles but no pre-incident familiarity.
A potential explanation for this trend is that individuals that share similar roles and/or stakeholder groups may be more likely to make assumptions about the other person’s approach to, or understanding of, a given situation, leading to false expectations and misunderstandings.
This suggests that to reduce problematic communication, responders who lack familiarity with each other must emphasize clear communication and refrain from making assumptions about the other person’s knowledge or strategy, regardless of how similar their institutional roles are…”
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The information above is based on the following article: Nowell, B., & Steelman, T. 2015. Communication under Fire: The Role of Embeddedness in the Emergence and Efficacy of Disaster Response Communication Networks. Journal of Public Administration Research and Theory 25 (3): 929-952. doi: 10.1093/jopart/muu021.
Dr. George Fischbeck, a legendary meteorologist, passed away last year. When I worked in southern California many of us would watch Dr. George’s weather presentation on ABC7 news every chance we had. He was very knowledgeable, fun to watch, and introduced many viewers to the fine art and science of weather observation and forecasting.
