A probability method for predicting time-dependent long-term shoreline erosion

This paper describes a practical procedure for predicting the probability distributions of long-term shoreline erosion. It treats the dynamical response of the shoreline over time as that of a time-dependent stochastic system. The input to the system are the long-term wave climate and shoreline properties while the output of the system are the probability distributions of the maximum shoreline recession within any prescribed time period. The procedure enables the combined effect of the longshore and cross-shore sediment transport processes on the shoreline erosion to be taken into account as both processes are generally responsible for the maximum shoreline recession. A series of simulations using idealised long-term wave distributions which have relatively narrow directional spread was carried out to evaluate the capability of the method. Based on these simulations it was found that both the distributions and variability of wave climates have significant influence on the predicted shoreline erosion probability distributions while the chronology effect is less significant, especially for long simulation time. (C) 1999 Elsevier Science B.V. All rights reserved.