From the Sierra Sun Times – October 3, 2021 – As firefighters bring some of this year’s most devastating wildfires to heel, California Geological Survey (CGS) geologists are already scouting the blackened ground for signs of a secondary hazard – potential debris flows.
Debris flows follow infernos and can sometimes be just as dangerous to life and property.
What Causes Debris Flows? After wildfires eliminate the trees and undergrowth on sloped areas, only bare soil, rock, and fire debris is left on the surface. When it rains hard and long enough in a burned area, that material turns into a slurry several feet thick traveling downhill faster than a person can run, capable of damaging structures, burying roads, and clogging streams. (more)