Erosion of a Seaward Dike Slope by Wave Action

Abstract

A dike erosion model is developed to predict the temporal and cross-shore variations of vertical erosion depth under irregular wave action. The product of the erosion rate and the turf resistance force is related to the rate of erosion work by turbulence generated by wave energy dissipation caused by wave breaking and bottom friction. The turf resistance force is expressed using the turf thickness and the surface and underneath resistance parameters. The empirical parameters are calibrated using available data. The calibrated model is shown to reproduce the relation between the limiting velocity and steady flow duration, the erosion rate on a seaward grassed slope, and the eroded profile evolution of a seaward clay slope. The turf resistance parameters are uncertain and will need to be calibrated for specific dikes.