Predicting the size and frequency of landslides is essential in landslide risk assessment. Records of past landslides are invariably incomplete and often provide little guidance on infrequent events. Presenting size frequency models graphically has the advantage of showing how observations, interpretations and judgements are interrelated, allows patterns to be recognized and understood, and models for different situations to be easily compared. Slope retreat rates were used to calibrate landslide size frequency models for individual slope units on an oversteepened escarpment above a road threatened by landslides in Australia. Evidence based models should be developed early and should be based on how slopes form and fail over a range of time scales. The size of deposits, historical records and measured movements can be used to help assess landslide process rates. Regional models can help in the judgement of how a particular slope may behave.
This conference paper was originally published as Moon, AT, Wilson, RA and Flentje, PN, Developing and using landslide size frequency models, in Proceedings of the International Conference on Landslide Risk Management, 18th Annual Vancouver Geotechnical Society Symposium, Vancouver, 31 May - 4 June 2005, 589-598. Joint Technical Committee on Landslides and Engineered Slopes, JTC-1, in association with Vancouver Geotechnical Society.