Landslide hazards and climate change in high mountains

• Main Authors: Huggel, Christian, Korup, Oliver, Gruber, Stephan
• Format: Book Part
• Language: English
• Published: Elsevier 2021
• Subjects: Institute of Geography; 910 Geography & travel; Cold Mountain; Ice; permafrost
• Online Access: https://www.zora.uzh.ch/id/eprint/211544/; https://www.zora.uzh.ch/211544

Climate change has become evident in mountain regions worldwide and is manifested by an increase of mean temperatures and often by more intense rainstorms. Many types of landslides are inherently linked to climate variables, and therefore, the concern that climate change may increase landslide hazards is growing. However, so far limited research has been done on detecting a signature of climate change in observed landslide activity. High-mountain regions feature glaciers, permafrost and snow that all are sensitive to temperature changes and temperature-driven instabilities, thus inviting consideration in studies of how climate change affects landslide activity. Here we first adopt a statistical perspective and perform stochastic experiments using large numbers of simulated landslide inventories to test whether we can detect a change in landslide magnitude-frequency relations due to climatic disturbance. We found that the widely used power-law distribution of landslide frequency and magnitude is likely insensitive to reveal significant changes in landslide activity. Second, we address the subject on the level of processes and evidence from several recent case studies. We analyze a series of large slope failures that occurred in recent years in different regions worldwide, and distinguish between (i) rock and ice avalanches, (ii) debris flows from deglaciated areas, and (iii) landslides that interact with glacial and river processes. Finally, we briefly review methods of slope stability assessment and mass movement modeling and their application to landslides in cold mountain regions subject to climate change.