The role of the tidal and wind forces on the hydrodynamic flow pattern in the Augusta Harbour (Italy)

The hydrodynamic circulation in the coastal area of the Augusta Bay (Italy) is analysed in the present paper. The Augusta Harbour is an important economic infrastructure located in the eastern part of the Sicily. Due to the heavy contamination generated by many chemical and petrochemical industries active in the zone, the harbour was declared as Contaminated Site of National Interest. In order to mitigate the risks connected with the industrial activities located near the harbour it is fundamental to analyse the hydrodynamic circulation. Since no significant change exists in the water density, the current inside the Augusta Bay is mainly due to the relative contribution of the wind force acting over the free surface and the tidal motion through the mouths. Tidal oscillations measured at the eastern mouth and the wind measured in the meteorological station closest to the coastal area were imposed in the numerical simulation. Due to the geometrical complexity of the domain and the presence of several piers along the coast, a curvilinear boundary-fitted computational grid was used, where the cells corresponding to land areas or to the wharfs were excluded from the computation. In order to validate the numerical model, comparisons between numerical results and field measurements were performed. On the basis of the numerical results, the estimation of the current in the basin was achieved, showing the specific role of wind and tidal oscillation in the hydrodynamic circulation inside the harbour