Statistical Modeling of Pressure Gradients on a Barred Beach

Abstract

This paper reports the cross-shore variations of a pressure gradient observed on a fixed barred beach in a large-scale laboratory wave flume. The data sets include measurements of the free water surface elevation, the near-bottom velocity and the near bottom pressure and the pressure gradient for one irregular wave and three regular wave cases. The cross-shore variation of the pressure gradient showed that the maximum value of pressure gradient appeared in the area of wave breaking, and the pressure gradients were influenced by the fluctuation of water surface elevation. The exceedance probabilities of pressure gradient were analyzed using irregular wave case data. Comparison of the onshore and offshore directions of the exceedance probability showed that the onshore direction dominant in this experiment; its values were generally large over the bar. The distribution of the exceedance probability of pressure gradient could be evaluated by the Weibull distribution.