The expected frequency of avalanche events is an essential component of risk in land-use
planning and design of avalanche defences in the runout zone. In the past, detailed field studies
have been undertaken to determine the frequency of avalanches on individual paths, but there
have been few studies to determine the frequency analytically from terrain variables or to
determine a probability distribution from which formal risk calculations can be made.
In this thesis, I present an analysis based on extensive field measurements for high-frequency
avalanche paths (return period less than 30 years). My study focuses on two
important aspects:
(1) calculation of extreme runout on high-frequency avalanche paths using terrain variables.
(2) determination of the probability-density or probability-mass function for high-frequency
avalanche paths as an input to risk assessment.
By virtue of the extensive database, the work in this thesis represents the most comprehensive
study of high-frequency avalanche paths now in existence. The results will find application in
land-use planning studies, risk mapping calculations and design of avalanche defences.