1. a University of Natural Resources and Applied Life Sciences, Institute of Mountain Risk Engineering , Peter Jordanstrasse 82, 1190, Vienna, Austria
2. b University of Natural Resources and Applied Life Sciences, Institute of Mountain Risk Engineering , Peter Jordanstrasse 82, 1190, Vienna, Austria E-mail:
3. c Swiss Federal Research Institute WSL , Zürcherstrasse III, 8903, Birmensdorf, Switzerland
4. d Institute of Mountain Risk Engineering , Peter Jordanstrasse 82, 1190, Vienna, Austria E-mail: