Inhalt und Ziel des Forschungsprojekts
Dieses Projekt zielt darauf ab, die wichtigsten Prozesse zu untersuchen, die die Bewegung von Murgängen beeinflussen. Konkret geht es darum, 1) neu entwickelte Umweltsensoren einzusetzen, um die wesentlichen Eigenschaften von sich bewegenden Murgängen zu messen, 2) zu quantifizieren, wie die Wechselwirkung von Feststoffpartikeln und Wasser die Geschwindigkeit und Auslaufdistanz von Murgängen bestimmt und 3) einen neuen numerischen Modellierungsrahmen zu entwickeln, der die jüngsten Fortschritte der Computerarchitektur nutzt, um die Wechselwirkung der untersuchten Mechanismen zu simulieren.
Wissenschaftlicher und gesellschaftlicher Kontext des Forschungsprojekts
Im Rahmen dieses Projekts werden neue Methoden zur Messung und Modellierung von Murgängen entwickelt, mit denen wichtige Erkenntnisse über das Fliessverhalten von Murgängen gewonnen werden können. Dieses neue Verständnis wird Praktikern und Entscheidungsträgern dabei helfen, die Murganggefährdung für die Bevölkerung sowohl in der Schweiz wie auch im Ausland zu reduzieren.
Every year, landslides kill thousands of people and cause billions of dollars in infrastructure damage worldwide (Petley, 2012). Landslides are a common and costly natural hazard in Switzerland, as demonstrated by the recent landslide that impacted the town of Bondo, in Canton Graubünden, killing eight people. Increased development pressures in high risk areas, as well as melting permafrost and increased frequency of severe rainstorms, is expected to change landslide risk worldwide. Developing a detailed understanding of the fundamental mechanisms that govern landslide motion is crucial for managing this changing risk in the future.Some of the most catastrophic landslides are flow-like landslides, such as debris flows, where the failed material behaves as a fluid. The mechanisms that govern flow-like landslides are poorly understood at present, which limits the ability of researchers and practitioners to manage landslide risk. The three most important mechanisms that govern flow-like landslide motion are: 1) longitudinal sorting, which leads to destructive surges 2) liquefaction, which dramatically increases the area impacted by the landslide and 3) material entrainment, which can increase the volume of the flow by orders of magnitude. New methods to measure and model these mechanisms are urgently needed to manage landslide risk in the future. Through developing and applying new field data collection techniques, performing innovative analogue experiments and implementing a cutting edge numerical model, we will generate important new insights into these three important mechanisms. Specifically, the objectives are: 1) measure longitudinal sorting and entrainment in moving debris flows, 2) quantify how liquefied strength governs flow-like landslide motion and 3) develop a new numerical modelling framework that leverages recent advances in computing architecture to simulate the interaction of the three studied mechanisms.The Mountain Hydrology and Mass Movements group at WSL, which is the host institution for this research project, operates the Illgraben Debris Flow Observation Station (IO), and has two state-of-the-art analogue modelling facilities. This existing infrastructure will be leveraged to perform novel field and analogue modelling investigations. High frequency LiDAR sensors, which provide high-resolution measurements of the surface of objects, will be installed in the IO measure longitudinal sorting and entrainment in moving debris flows. This data has not been previously collected, and will provide unique insights into these mechanisms. This dataset will be made available to the scientific community to encourage further innovation. Analogue experiments, which systematically vary the factors controlling liquefied strength, will be performed to quantify how liquefaction influences landslide runout. The results from both the field and laboratory investigations will be incorporated into a new numerical modelling framework. This numerical model will simulate the interaction of longitudinal sorting, liquefaction and entrainment, which is beyond the current capabilities of similar models.The novel field and laboratory data will provide an unprecedented level of detail about the mechanisms of longitudinal sorting, liquefaction and entrainment. Incorporation of this data into numerical models will illuminate the physical causes that govern the motion of flow-like landslides and reveal a new fundamental understanding of this landslide type. This new understanding of landslide mechanisms is crucial for managing landslide risk in an uncertain future.
Last updated:07.06.2022
