ABSTRACT
Errors in estimating the risks from landslides can be regarded as the sums of errors in estimating the elements at risk, in particular landslide hazards, vulnerability of those elements to the hazards and the frequency of the hazards. Estimates of rock fall frequency at the Argillite Cut on British Columbia’s Highway 99 are based on records from the 33 year history of the Cut and range over at least an order of magnitude. Elements at risk range over 6 orders of magnitude. Little has been published about vulnerability in rock falls. Rock fall hazard is probably negatively correlated with vulnerability and the elements at risk. The range of plausible risk estimates at the Cut might be two orders of magnitude.
