Mathematical modeling of talus development

A new mathematical model for talus development and retreat of cliff behind the talus was constructed. This model includes both the rate of declining retreat of cliff (vθ) and the rate of parallel retreat of cliff (va) independently. It can, therefore, reproduce diverse topographic changes having various ratios of vθ to va. The model was applied to the result of a field experiment for talus development at a cliff composed of chalk. The calculated form by the model was in good agreement with the field observations. This agreement validates the model.