Wave observations and refraction modelling in intermediate water depths off the lagoon of Venice

This paper describes wave measurements and the associated refraction studies made in the area off the coast of Venice. The wave data have been collected at four different locations, using four different systems. The refraction due to depth variation has been studied by means of a ray refraction model based on the linear theory. A wide range of frequencies and directions has been considered. For each combination a very dense ray system has been traced, to obtain a general description of the field with high spatial resolution. The linear approach allows to build transfer matrices of the wave conditions between an input spectrum at the border of the considered area and specified locations. The results have been obtained at longshore sections and, in particular, at the main harbour entrance. We have also studied the implications of the presence of currents in the coastal area. Lacking measurements and suitable modelling, we have deduced from the wave measurements the currents that could correlate the data obtained at the different locations.