Tons of debris, mud and water rush precipitously down mountainsides into valleys during mudslides. To gain a better understanding of the forces at work, the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) is using a special scale equipped with measurement technology from HBM.
"If you've ever seen a mudslide rush down a mountain, you won't soon forget the thundering and roaring," said Dr. Yolanda Deubelbeiss, a scientist with WSL.
Mudslides occur frequently in the mountains during or after heavy precipitation or when the snow melts. When loose material becomes saturated with water, it starts to slide, taking more debris down with it along the way. Trees and boulders can also be caught up in the flow and tumble down to the valley, often following the course of creeks or gullies at speeds up to several meters per second, with devastating results for everything in the way. "It is especially dangerous if the mudslide takes a new route outside a creek bed. Then it can cause serious damage to houses, bridges or roads," explained the geologist.
Hazard maps indicate the extent to which an area is at risk of mudslides and how much damage could potentially occur. They are based partly on the results of computer simulations using defined scenarios but also, and more importantly, on field observations and damage data from earlier mudslides. This knowledge plays a role in regional planning or may lead to the construction of barriers and dams or widening of creek beds. "Computer models only allow us to draw theoretical conclusions about the flow behavior of a mudslide. To provide better protection for people against these enormous forces, we need a better understanding of what happens inside a mudslide. That will advance our work on the simulation models and make them more realistically reflect natural processes," explained Deubelbeiss. That might make it easier to predict, for example, how far some pieces could stray from the main flow.