Using Nonhydrostatic XBeach to Simulate Wave Transformations in Fringing Reef Environments

Abstract

Nearshore modelling in application for engineering disciplines is still in a state ofdevelopment due to high computational requirements and is difficult to calibrate consistently with field measurements. The scope of this study is to assess the feasibility and limitations of using the Nonhydrostatic version of XBeach (NonhXB, a two-dimensional (2D), phase resolved, depth integrated numerical model) to study the effects of nearshore wave transformations in a fringing reef environment. This study focused on finding the optimal grid size to simulate the breaker zone characteristics in a fringing reef environment by comparing NonhXB results alongside a dataset from a large scale wave flume test. The purpose of this study is to recommend a set of parameters which can be used to quantify the probability of wave breaking and provide a reasonable estimate of the breaker zone width; these parameters include grid resolution, breaker steepness parameter, reform steepness parameter and eddy viscosity. These recommended parameters should be further clarified by field observations in future applications.