What makes landslides go
Landslides bring a lot of devastation to the communities that fall victim to them. The properties of the flow that results from landslides are well understood, but their influence on the landslide overall remains unknown. The EU-funded GEOGRAF (Understanding geophysical granular flows: From small-scale experiments to full-scale simulations) initiative aimed to understand the physics of landslides in order to create predictive models for these natural disasters. The researchers designed laboratory experiments to determine what influences landslides the most. The researchers used a numerical simulation to investigate how different-sized particles influence the flow of a landslide. They also investigated the role played by the roughness of the surface over which a landslide flows by using different surfaces in the laboratory. GEOGRAF was able to develop a new understanding of how smaller objects in a landslide interact with larger objects such as boulders. The researchers found that larger objects tend to separate from the flow to the edges, where they build a channel that enhances the flow. The team also found that the roughness of the surface greatly influenced the flow of a landslide, much more than different-sized particles in the flow does. Understanding landslides better will help researchers propose improved safety measures, and may ultimately save lives in communities affected by these natural disasters.
