SBEACH: Numerical Model for Simulating Storm-Induced Beach Change. Report 1. Empirical Foundation and Model Development
Abstract
A two-dimensional numerical model is presented for calculating dune and beach erosion produced by storm waves and water levels. The empirically based model was first developed from a large data set of net cross-shore sand transport rates and geomorphic change observed in large wave tanks, then verified using high-quality field data. The aim is to reproduce macroscale features of the beach profile, with focus on the formation and movement of longshore bars. The ultimate goal is prediction of storm-induced beach erosion and post-storm recovery. Bars are simulated satisfactorily, but berm processes are less well reproduced, due in part to a lack of data for defining accretionary wave and profile processes. A new criterion is developed for predicting erosion and accretion, and the model uses this criterion to calculate net sand transport rates in four regions of the nearshore extending from deep water to the limit of wave runup. Wave height and setup across the profile are calculated to obtain the net cross-shore sand transport rate. The model is driven by engineering data, with main inputs of time series of wave height and period in deep water, time series of water level, median beach grain size, and initial profile shape. Comprehensive sensitivity testing is performed, and example applications are made to evaluate the response of the profile to the presence of a vertical seawall and behavior of different beach fill cross sections in adjustment to normal and storm wave action. Keywords: Accretion; Cross shore sand transport; Dune erosion; Longshore bars.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1989
- Accession Number
- ADA212212
Entities
People
- Magnus Larson
- Nicholas C. Kraus
Organizations
- Coastal Engineering Research Center