Image provided by: University of Oregon Libraries; Eugene, OR
About The nugget. (Sisters, Or.) 1994-current | View Entire Issue (Dec. 20, 2017)
16 Wednesday, December 20, 2017 The Nugget Newspaper, Sisters, Oregon Smaller branches pack the biggest fire-spreading punch By Steve Lundeberg AP Writer CORVALLIS — As the West tallies the damages from the 2017 wildfire sea- son, researchers at Oregon State University are trying to learn more about how embers form and about the blaze-starting potential they carry. Pr eliminar y findings indicate the diameter of the branches that are burning is the biggest single factor behind which ones will form embers the most quickly and how much energy they’ll pack. “Increased population in the wildland-urban interface means increased risk to life and property from wildland fires,” said Tyler Hudson, a graduate student in the College of Engineering. “Spot fires started by embers lofted ahead of the main fire front are difficult to predict and can jump defensible space around structures.” Research shows smaller- diameter branches are better at producing embers, also known as firebrands. “Embers are wildfires’ most challenging mode of causing spread,” said David Blunck, assistant professor of mechanical engineering. “By understanding how embers form and travel through the air, scientists can more accu- rately predict how fire will spread. We have a multiscale approach that involves burn- ing samples in a laboratory setting, larger burns – burn- ing 10-foot-tall trees – and then working with the U.S. Forest Service to participate in prescribed burns.” In his lab, Blunck’s research group controls mul- tiple parameters which can influence generation rates: fire intensity, crosswind velocity, species of tree, diameter of the sample, fuel condition (natural vs. pro- cessed), and moisture con- tent of the fuel. “Fire intensity had little effect on the time needed for ember generation,” Hudson said. “And natural samples and dowels with similar diameters can have quite different ember generation times.” Using samples of Douglas fir, western juniper, pon- derosa pine and white oak with diameters of 2 and 6 millimeters, the researchers determined that 2-millimeter samples generated embers roughly five times as fast as 6-millimeter samples. This trend can be explained by the observa- tion that the bending stress is proportional to 1 divided by the cube of the diameter – thus, the larger the diam- eter, the smaller amount of bending stress and a lesser likelihood of breakage, and ember creation. Moreover, smaller diameters have less fuel that needs to be burned. In the field, researchers can track embers’ energy “from the time they leave the tree until they get to their destination,” Hudson said, using techniques ranging from infrared videography to measuring scorch marks on squares of fire-resistant fabric placed on the ground at varying distances from the fire. Quality Truck-mounted CARPET CLEANING Quality Cleaning 16 years in Reasonable Prices Sisters! — Credit Cards Accepted — • Locally owned and operated • Large natural & organic selection • Meat cut & ground fresh daily • Huge bulk-foods department • Only 20 minutes from Sisters Located in the Cascade Village Shopping Center, Bend Open every day, 6 a.m. to 11 p.m. Enjoy the Holiday Season at THE GALLERY RESTAURANT AND BAR SOUP OF THE DAY Dec. 20th - Dec. 26th Sat.......................Chicken Rice Wed ................. Corn Chowder Sun ...........Split Pea with Ham Thurs ........... Beefy Mushroom Mon ....Merry Christmas! Closed Fri Clam Chowder & Vegetable Tues ............ Butternut Squash Breakfast & lunch 6:30 a.m.-2:30 p.m. Full-service dining in the bar nightly until 10 p.m. (21 & over) 171 W. Cascade Ave., Sisters • 541-549-2631 ENVIROTECH 541-771-5048 Licensed • Bonded • Insured • CCB#181062 RESIDENTIAL • COMMERCIAL Blunck, Hudson and fel- low mechanical engineering graduate student Mick Carter presented their prelimi- nary findings in April at the 10th edition of the biennial U.S. National Combustion Meeting in College Park, Maryland. In August, Blunck was among a group of collabo- rators receiving a $500,000 grant from the National Institute of Standards and Technology “for the devel- opment of a computer model that will define patterns for firebrand distribution dur- ing wildland-urban interface fires and their likelihood of igniting nearby structures.” This past fire season in Oregon, roughly 2,000 fires combined to burn more than a half-million acres – that’s about 1,000 square miles, an area the size of Rhode Island. One of the most devas- tating of those blazes was the Eagle Creek fire in the Columbia River Gorge, which scorched nearly 50,000 acres and threatened the historic Multnomah Falls Lodge – and provided a ter- rifying illustration of what embers can do. “The fire jumped the river and started burning in Washington because of embers,” Blunck said. “We estimate that the fire jumped 2 miles across the river.” Veterans’ Services Serving those who’ve served. 541-585-VETS (8387) | www.deschutes.org/vets 2013 Chevrolet Silverado 4x4 K1500 Extra cab, LTZ, snow white, 80k loaded! Dad needs a new ride for Xmas. $25,900 Best Price! No Hassles! CAR CARFAX ARFAX FAX Ce Certifi rtifi rti t fied! Buy or sell your car with locally owned ... Sisters Car Connection (Low miles • newer than 2005) 541-815-7397 102 W. Barclay Dr., Sisters
