Tsunami Response in Semienclosed Tidal Basins Using an Aggregated Model

Abstract

An aggregated model to evaluate tsunami response in semienclosed water bodies is presented in this work. The model is based on one-dimensional shallow water equations and can include long-wave external forcing such as a tsunami. It has been successfully validated against experimental data from a physical model, and its predictions for a case study have been compared with results from the Cornell multigrid coupled tsunami (COMCOT) model. The model can be used as a predictive tool because a calibration using a theoretical value for expansion and contraction losses has been performed and differences with the typical calibration are less than 10%, which is considered acceptable. This allows using the model in the absence of measured data, which is very difficult to obtain in case of a tsunami event. A case study for the Gulf of Cádiz (Spain) has been simulated with the COMCOT model. The aggregated model predicted the response for a harbor more accurately than for estuarine systems with tidal flats. Nevertheless, the aggregated model has been demonstrated as a useful general tool to predict the response of semienclosed tidal basins to a tsunami event, and hybrid models coupling advanced models to simulate ocean tsunami propagation with the model presented here would be useful in developing coastal warning alert systems.