Simulation of storm surge events at the portuguese coast (viana do castelo)

Abstract

An approach for simulating storm surge events was investigated and presented in this work. The storm surge event that occurred in the North of Portugal (Viana do Castelo), during the period of 14th -16th October 1987 was considered. In the definition of the computational domain, the path of the storm was considered, among other aspects. A tidal harmonic analysis was made to the tide gauge observations to extract the tidal components, enabling the determination of the sea level residuals. The ADCIRC model was used for the hydrodynamic modeling, which included different forcing mechanisms. Simulations were carried out for evaluating the model performance and to investigate possible nonlinear interactions between tidal and meteorological forcing. In this way, three types of simulations were carried out: modeling of the astronomical tides, with tidal forcing at the open boundary; modeling of the storm surge, using meteorological forcing only, and simulations including both tidal and meteorological forcing. Results show that there is some non-linear interaction between astronomical and meteorological forcing and that the observed sea levels are partially explained by this forcing. It was concluded that to obtain a better reproduction of the storm event, further simulations are required.