Geometric Characteristics of Storm Beach Profiles

Abstract

A simple cross-shore sediment transport model based on a wave energy dissipation approach is used to analyze prominent storm beach profile features. The model provides a general functional form relating various geometric characteristics of a storm profile to two well known dimensionless parameters-the surf zone parameter and the dimensionless sediment fall velocity. An extensive regression analysis was performed on existing laboratory data to test the validity of the model. Features examined include bar geometries, erosion length and the location of equilibrium point. The two dimensionless parameters are shown to be effective in describing the bulk characteristics of prominent storm profile features. Based on the analysis, predictive equations of storm beach profiles' geometries are proposed. The experimental findings and the predictive equations reveal that both milder slopes and larger waves would produce breaking bars offshore. The similar functional form of the bar crest depth and equilibrium depth suggests that a similarity profile may exist on the inshore face and opens the possibility to extend the equilibrium equations to storm profiles' configurations. The results provide a more comprehensive parameterization of storm profiles than the commonly employed equilibrium profile equations.