Predictions of run-up scale on coastal seawalls using a statistical formula

This paper presents predictions of run-up scale on coastal structures using a multiple linear regression equation. The Wonnapha Beach seawall in Chon Buri, Thailand, is used as the study site. Instead of exactly measuring wave run-up on structures, run-up levels were observed and categorized into five scales (from 0 to 4). Run-up scales, together with the data of tidal levels, offshore waves, and winds, are analyzed using multiple linear regression. A new parameter, “effective wind speed,” is introduced by merging wind direction and speed into one parameter explaining more physical meaning of wind influences on wave run-up. The regression formula can reproduce observed run-up scales with an R_^2 of 0.589 and the mean absolute error of 0.62. For this study, the predictive formula can be applied as a real warning for the near future since simultaneous data is used; however, applying this approach while using forecasted input data would be a useful and timely warning tool for alerting people who live near coastal defenses about potentially hazardous run-up conditions.