A comparison of two runout programs for debris flow assessment at the Solalex-Anzeindaz region of Switzerland

Debris flows are a major consideration in land-use planning and assessing the integrity of infrastructure in mountainous regions. In the present study, two computer programs, "Flow-R" and "DebrisFlow Predictor," are used to simulate debris flows in the Solalex-Anzeindaz region of the Swiss Alps, where many historic debris flow hazards are known. Both tools use the same Digital Elevation Model. Flow-R simulates the process based on spreading and runout distance algorithms.

DebrisFlow Predictor uses a set of probabilistic rules for scour, deposition, path selection, and spreading. In the present simulations, both programs give comparable results in terms of spread. However, the additional information on the area, volume, and depth of debris along the landslide path provided by the DebrisFlow Predictor might make it a better hazard assessment tool.