PROBABILISTIC PERFORMANCE OF BEACH NOURISHMENT PROJECTS

A relatively simple computer model is developed to investigate the probabilistic lifetime of beach nourishment projects with the goal of estimating the probability distribution for re-nourishment intervals. The method accounts for randomness and uncertainties in the beach fill response through Monte Carlo simulation. The simulation model requires that all input variables be defined probabilistically through their mean value, standard deviation, and probability distribution type. Beach fill response is then simulated using a collection of simple analytical models for: (1) long-term background erosion, (2) seasonal erosion/accretion cycles, (3) longshore spreading of the fill using the Pelnard-Considere solution, and (4) erosion due to storms using the Kriebel and Dean analytical erosion model. Results are presented as histograms of re-nourishment interval.