Abstract

Wildfires affect the coupled dynamics of vegetation, runoff response, and sediment production, as well as the sequencing of post-fire precipitation and snowmelt in forested watersheds. We examined these interactions by applying a spatially distributed hydrologic model to multiple-year periods before and after a major fire that occurred in 1970 in the Entiat River basin, Washington. The effects of precipitation sequencing on post-fire sediment delivery were examined by simulating the 1970 fire as if it had occurred at other times in a 50-year period. Simulated sediment delivery varied by a factor of two depending on fire timing. We also compared the effects of fire suppression and found that simulated sediment production was about 20% higher for natural compared with current conditions.