Extreme Inundation Statistics on a Composite Beach

TL;DR

This study uses numerical simulations to analyze wave runup and inundation statistics on a beach, considering nonlinearity, wave breaking, and wave spectrum effects, proposing a Weibull model for extreme inundation prediction.

Contribution

It introduces a comprehensive numerical approach to quantify extreme inundation statistics considering wave nonlinearity and breaking, and proposes a Weibull distribution model for extreme runup heights.

Findings

Wave nonlinearity influences runup height distribution.

Wave breaking significantly affects inundation statistics.

Weibull distribution effectively models extreme runup heights.

Abstract

The runup of initial Gaussian narrow-banded and wide-banded wave fields and its statistical characteristics are investigated using direct numerical simulations, based on the nonlinear shallow water equations. The bathymetry consists of the section of a constant depth, which is matched with the beach of constant slope. To address different levels of nonlinearity, the time series with five different significant wave heights are considered. The selected wave parameters allow also seeing the effects of wave breaking on wave statistics. The total physical time of each simulated time-series is 1000 hours (~360000 wave periods). The statistics of calculated wave runup heights are discussed with respect to the wave nonlinearity, wave breaking and the bandwidth of the incoming wave field. The conditional Weibull distribution is suggested as a model for the description of extreme runup heights and assessment of extreme inundations.