Aug. 12, 2020
CWU Research Determines Regional Wildfires Lead to Earlier Snowmelt
Wildfires not only consume valuable timberland, but they also accelerate snowmelt, which can affect watersheds throughout the western United States. Research conducted by Central Washington University alumnus Ted Uecker, CWU geological sciences professor Susan Kaspari, and fellow peers have measured this earlier snowmelt, as well as determined how its effects vary in wildfire areas throughout the eastern Cascade Range.
Results of their study, “The Post-Wildfire Impact of Burn Severity and Age on Black Carbon Snow Deposition and Implications for Snow Water Resources, Cascade Range, Washington,” were recently published in the respected Journal of Hydrometeorology.
“When snow is removed up to three-weeks earlier it matters because it depletes water resources that are needed later in the summer,” said Kaspari. “It also extends the potential wildfire season.”
Wildfire can affect the snowpack by removing the canopy which allows more sunlight to reach the surface, and it also deposits black carbon (also called soot) on the snow, which darkens the surface and allows more solar energy to be absorbed.
The Table Mountain burn area was the primary survey site. Located about 20-miles northwest of Ellensburg, it was set ablaze in 2012.
“That was a high-severity fire right in our backyard, which made it a really good location,” Kaspari added. “There were three SnoTel [snowfall measuring] sites across the Table Mountain area. One in the high-severity area completely burned out. Another one, within nine miles, didn’t burn at all. So, with sites in and outside the burn area, it allowed us to establish how a wildfire accelerates snowmelt compared to an area that was not affected.”
"We also studied the 2006 Tripod fire in north-central Washington and another fire from 2015,” said Uecker, now a state Department of Ecology hydrogeologist. “What we found was the effects of the black carbon deposits [on speeding up snowmelt] tapered off after 10 years.”
Keith Musselman, a research associate at the University of Colorado Boulder Institute of Arctic and Alpine Research, and geography professor S. McKenzie Skiles at the University of Utah, also were members of the study team that published the research. Kaspari will present the research at the American Geophysical Union’s Fall Meeting 2020 in December. It may also prove useful for future forest planning efforts, Uecker said.