Simulation of some debris flows in Klanawa watershed in Vancouver, British Columbia

Debris flows are steep mountain hazards that may impact infrastructure, human life and environment considerable distance from their source. Runout simulation tools often require site-specific parameters that may be difficult to estimate or impractical to deploy at a regional scale. In contrast, models that do work regionally tend to provide limited data to the user. In this study, a relatively new agent-based simulation program called DebrisFlow Predictor was used to estimate the scour, deposition and volume of debris flows which occurred in a selected area of the Klanawa Watershed in Vancouver Island, British Columbia.

This program employs a group of autonomous subroutines, or agents, that act on a digital elevation model (DEM) using a set of probabilistic rules for scour, deposition, path selection, and spreading behavior. The advantages of this program are that it requires limited input, including DEM and user-defined initiation zones, and only modest computational power.