Wildfires don’t stop being dangerous after the flames go out.
Wildfires don’t stop being dangerous after the flames go out. Even one modest rainfall after a fire can cause a deadly landslide, according to new UC Riverside research.
“When fire moves through a watershed, it creates waxy seals that don’t allow water to penetrate the soil anymore,” explained environmental science doctoral student and study author James Guilinger.
Instead, the rainwater runs off the soil surface causing debris flows, which are fast-moving landslides that usually start on steep hills and accelerate as they move.
“The water doesn’t behave like water anymore, it’s more like wet cement,” Guilinger said. “It can pick up objects as big as boulders that can destroy infrastructure and hurt or even kill people, which is what happened after the 2018 Thomas fire in Montecito.”
Read more at University of California - Riverside
Image: House damaged by debris flows generated in Los Angeles County's Mullally Canyon in response to a rainstorm on February 6, 2010. (Credit: Susan Cannon/USGS)
