Advancing debris flow hazard and risk assessments with modeling and rainfall intensity data

Stantec’s Dr. Rick Guthrie, Dr. Thad Wasklewicz, Graham Knibbs, and Rebecca Rossi discuss how the prediction of post-wildfire debris flows has been a constant theme of geomorphology and geohazard research. Climate change has been linked to increased magnitude and frequency of wildfires in many parts of the world and an expected increase of extreme rainfall following wildfires, which have further complicated our ability to predict debris flow occurrence and heightened the need for scientists and engineers to rapidly advance our understanding of post-wildfire debris flow initiation, runout, and inundation.

Here, a combination of rainfall intensity thresholds and debris flow modeling: (1) provides new insights into the likelihood of debris flows and (2) advance our understanding of debris flow volume estimates. Probabilistic runout and inundation models help advance analyses beyond the empirically derived watershed approaches used in debris flow hazard assessment and volume measurement tools used in the United States.