Prediction of dune erosion due to storms

This paper presents results of experimental and mathematical modelling of beach and dune erosion under storm events. Re-analysis of the experimental results on dune erosion in small-scale and large-scale flumes shows that the dune erosion for extreme conditions is somewhat smaller than that based on earlier analysis results.Dune erosion caused by wave impact has been modelled by a cross-shore profile model (CROSMOR-model), which is based on a ‘wave by wave’ modelling approach solving the wave energy equation for each individual wave. The model has been applied to the recent Deltaflume experiments on dune erosion. The three main processes affecting dune erosion have been taken into account: the generation of low-frequency effects, the production of extra turbulence due to wave breaking and wave collision and the sliding of the dune face due to wave impact. The calibrated model can very well simulate the observed dune erosion above the storm surge level during storm events in small-scale facilities, large-scale facilities and in the protoype (1953 storm in The Netherlands) using the same model settings. The mathematical model results have been used to develop a new simplified dune erosion rule.