Wave height distribution in unsaturated surf zones

Abstract

This paper addresses the performance of different wave height distributions in the surf zone on natural beaches on the central west coast of India. The surfzone water level data for different surf zones were analyzed using Fast Fourier Transformation techniques to obtain the wave characteristics viz., wave height, and wave period. Different probability density functions (pdfs) were fit for the surf zone wave heights to identify the best-fit pdf. The quality of the surf zone wave modeling depends on the skill of the identified best-fit pdf in explaining the measured wave height distribution. This study further reiterates that the Rayleigh and Exponential pdfs are a poor fit for the surf zone wave heights. However, Kernel, GEV, and Logistic pdfs were observed to very well fit the surf zone waves. A constant value of power p=2 in the Rayleigh distribution is not suitable for the central west coast of India. The power p varies for different surf zones, and it also varies spatially and temporally. In this study, a simplified approximation for p is estimated using the maximum and the minimum values of significant wave height, root mean square wave height and the total number of waves. This improved Rayleigh pdf was applied for the surf zone waves measured at different locations along the central west coast of India and found to be fit.