Movable‐Bed Modeling Law for Coastal Dune Erosion

Abstract

Similitude relationships for the physical modeling of coastal dune erosion in movable‐bed models are developed based on consideration of the inertial forces, represented by the turbulent shear stress, and the gravity force in the nearly horizontal direction of the principal flow. This results in a dynamic scaling relationship for a distorted model. By requiring similarity of the dimensionless fall velocity parameter between the prototype and model and combining this criterion with the dynamic scaling, the necessary model distortion is derived. The main difference between these relationships and previous modeling laws is in the hydrological time scaling which is also distorted. The derived similitude relationships were verified by reasonable reproduction of the dune erosion which occurred during a prototype event. The model tests included a time‐dependent storm surge hydrograph and an increasing wave height as the storm progressed. It is concluded that the model verification has been successful in at least one instance where prototype data were available, but further verification is desirable as prototype data become available.