Prediction of Climate Change Forced Mass Movement Processes Induced in Periglacial Areas

Abstract

Based on glacier retreat and degrading permafrost in high alpine regions across the Bernese Oberland (Central Switzerland), several new hazardous source areas for processes became evident within the last years. The evaluation of susceptible periglacial areas and the assignment of resulting processes by modelling will be one of the major tasks to be solved in near future. The prediction of those processes and their consequences is an interdisciplinary question. Meteorological scenarios for the next 50 years derived from climate change scenarios stand at the beginning of the decision chain. Based on those, susceptible periglacial areas which act as starting zones for massmovements (rockfall, landslides, debris flows) or new sediment sources can be calculated through sophisticated permafrost and glacier retreat models. A vast basic monitoring of the permafrost by BTS measurements helps understanding on-going processes and is fundamental for the bedload calculation in the periglacial area, which is measured by monitoring systems at representative and characteristic locations within the study area (e.g. Spreitgraben near Guttannen, Switzerland). Dealing with large investigation areas of several 100 km2 it is important to use adequate models. Well established simulation tools have been used within the project. The result is a so called periglacial hazard indication map visualizing endangered areas in the year of 2060 for massmovement processes as well as other natural hazards like floods, glacial ice avalanche or subglacial lake outburst.