Probabilistic calibration of avalanche block models

Abstract

The Norwegian Geotechnical Institute (NGI) has been operating the full-scale avalanche test-site Ryggfonn in western Norway for more than 25 years. During those years, measurements from about three dozen dry-snow avalanches have provided information on front velocities and runout distances. Some of those measurements were used to calibrate a simple avalanche model following a well-defined probabilistic method.. Traditionally, model parameters of those kinds of models were evaluated from runout analysis disregarding any dynamics. The set of roughly 20 observed avalanches from one single path including, estimations of the front velocities at three points in the lower third of the track provided a unique opportunity for introducing uncertainty quantification methods for evaluating the performance of similar kind of competing models. We present the model calibration and results from the model performance testing.