New 3D Simulation Tool Improves Forecast of Alpine Mass Movements

(CONNECT) Johan Gaume from the Swiss Federal Institute of Technology in Zurich (ETH) and colleagues have simulated the landslides in Brienz 2023 and Blatten 2025 using a newly developed 3D modeling approach. The 3D model provides precise insights into flow dynamics, impact zones and run-off distances, thus enabling effective risk reduction, according to a press release.

Classic models of alpine mass movements are based on average depth, determine the average flow of the mass movement and calculate how fast and how high the total mass is and in which direction it is moving over the ground. However, these reach their limits when, as in Blatten, landslide masses move in many directions simultaneously in rugged terrain, explains Gaume in the press release. Gaume also works for the Institute for Snow and Avalanche Research (SLF) in Davos, part of the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) in Birmensdorf ZH.

The researchers simulated the Blatten landslide with a volume estimate of 10 million cubic meters of rock and ice, based on an estimated 5 million cubic meters of glacier volume and 3 to 5 million cubic meters of rock volume. The coefficient of friction, which indicates how easily a descending mass slides over the ground, was first estimated at 0.2, later at 0.23. According to the press release, the simulated spread of the fall mass proved to be very accurate at 1.2 kilometers on the southwest side of the valley and 700 meters on the northeast side.

In contrast to classic models, the new 3D tool was also able to capture the shock wave effect of the crash mass, which caused part of the flowing crash mass to be thrown into the air. "Overall, we have achieved a level of predictive accuracy that will allow our model to make more accurate assessments of complex alpine mass movements in the future - both in terms of how far they can spread down the slope and how much area they are likely to cover on the valley floor," explains Gaume. The scientists want to make the simulation tool available for practical applications and authorities in the future. ce/yes