Depositional and erosive effects over medium or short terms: The case of Lignano beach and inlet morphologies.

Hydro-morphodynamic processes are determinant in the morphological evolution of a lagoon inlet and its nearby features, such as the ebb tidal delta, and the barrier shoreline. In a transitional environment such as a lagoon, both tide and wind waves contribute to the dynamic balance of the environment; they act at different times scales, but both can have effects in the medium-long term. In this work the Lignano inlet, located in the Marano and Grado lagoon, has been considered as a study case. A possible method for characterizing the average year in terms of wind speed and direction, duration, and associated tide has been introduced, which consists in the identification and statistical analysis of events for the predominant wind regimes. The erosive and depositional effects on the Lignano inlet and on some nearby morphologies have been analyzed, following the simulation of the average year and of some storm surges of short duration but high intensity, by means of a 2DH shallow water hydro-morphodynamic numerical modeling. Both the duration of each event and its intensity contribute significantly to the reshaping of the inlet and adjacent morphologies, and both should therefore be taken into account in the modeling to estimate medium-long term effects. [ABSTRACT FROM AUTHOR]