Avalanche defence schemes

Snow avalanches are hazardous. They flow rapidly down mountain gulleys, destroying homes, built infrastructure and leading to fatalities. One way of mitigating against the hazards they pose is to build large structures in their flowtracks to deflect, retard and arrest the motion. This article describes some of the research that underpins modern guidelines of how to design these structures. It reports mathematical models that capture the transformation in the state of the flowing avalanche as it interacts with large-scale obstacles and the predictions that can be used to optimise engineering designs.