Optimization of Debris Flow Protection Structures: Insights from Physical Model Tests

Debris flows are among the most destructive natural hazards in alpine regions. Triggered by intense rainfall or rapid snowmelt, they transport water, sediments, and organic material at high speed and density, posing serious risks to settlements and infrastructure. Due to climate change, debris flow events are expected to increase in frequency and intensity, highlighting the need for effective and well-adapted protection measures. This webinar presents insights into the optimization of structural debris flow protection based on physical model tests conducted at the Hydraulic Engineering Laboratory of the Institute for Construction and Environment (IBU) at Eastern Switzerland University of Applied Sciences (OST). Physical modeling allows for detailed analysis geomorphological of complex processes under hydraulic realistic conditions, providing a solid basis for design, especially when combined with numerical simulations. Two case studies, the multi-stage protection system at Meretschi and the debris flow diversion system at Lienzer Lieu, illustrate how laboratory-scale models (1:40–1:60) were used to test and refine design parameters. Key outcomes include optimization strategies for overload scenarios and material variations. Additionally, the webinar will present initial results from a joint project with Water Matters Laboratory (WML), at K. N. Toosi University of Technology (KNTU), focused on developing a flood hazard mapping guideline tailored to conditions in Iran