G Liberatore

Wind and waves in the Northern Adriatic Sea

SummaryWe outline here the logical flow of papers that attack the problem of estimating the wave conditions in front of and at the Venetian littoral. We start from the determination of the wind fields, followed by that of the wave fields. The wave data are then transferred to the coast. We end by analysing the wave conditions inside the main inlet to the Venice lagoon. This paper gives a brief account of the logical flow of arguments from paper to paper, indicating the main results and outlining the robust structure of the overall research. We end with a discussion on the accuracy of the results, and with an indication of the possible lines for further research.

Waves in front of the Venetian littoral

SummaryThe second-generation HISWA model, specifically developed for shallow water areas, was used to estimate the wave conditions in front of the Venetian littoral. The model is based on the wave action equation, and it includes conservative interactions with bottom and currents, generation by wind and dissipation by bottom friction and breaking. A detailed sensitivity analysis has been carried out on the main processes that affect the output of the model. The performance of the model has then been checked by comparison with laboratory and field data. Finally, the HISWA model has been applied to several severe storms which have occurred in the Northern Adriatic and also to extreme wave conditions in the same area, thus allowing the corresponding wave conditions at the coast to be estimated. The results suggest that wave evolution towards the coast is greatly influenced by bottom friction in intermediate water depth and by breaking in shallow water. These processes could lead to saturation conditions during extreme wave events.

WAVE VELOCITY FIELD MEASUREMENTS OVER A SUBMERGED BREAKWATER

A special reflecting wall 12 m long and 2.1 m high was built off the beach at Reggio Calabria, and 30 wave gauges were assembled before the wall and were connected to an electronic station on land. It was possible to observe the reflection of wind waves generated by a very stable wind over a fetch of 10 Km. The experiment aimed to verify the general closed solution for the wave group mechanics (Boccotti, 1988, 1989), for the special case of the wave reflection.Significant features on Wadden Sea wave climate are evaluated in respect of the state of the art. Main emphasis was laid on an analysis of the governing boundary conditions of local wave climate in island sheltered Wadden Sea areas with extensions being sufficient for local wind wave growth. Explanatory for significant wave heights a reliable parametrization of local wave climate has been evaluated by using generally available data of water level and wind measurements.