Postfire Debris Flow Science Infographic

POSTFIRE DEBRIS FLOW SCIENCE

The U.S. Geological Survey helps local, state, and federal agencies assess debris flow hazards in recently burned areas. We provide information about the likelihood of debris flow activity, where they might happen, and how big they might be.

DEBRIS FLOW ASSESSMENTS

Wildfires can significantly alter the hydrologic response of a watershed to the extent that even modest rainstorms can produce dangerous flash floods and debris flows. The USGS conducts postfire debris flow hazard assessments for select fires in the western United States.

BY THE NUMBERS

• 483 - Number of postfire debris flow assessments the USGS completed between 2013 and 2023
• 14 - Number of states within the U.S. where postfire debris flow assessments were completed
• 22M - Millions of acres burned that were also assessed for potential postfire debris flow activity

POSTFIRE DEBRIS FLOW DASHBOARD

This postfire debris flow hazard assessment viewer shows forecasts of the likelihood that debris flows will occur in a recently burned area, as well as the volume of material that could be transported during a high-intensity storm. The debris flow models rely on characteristics like basin shape, burn severity, soil properties, and rainfall intensity.