Sediment redistribution at a river mouth: The case of Lignano Sabbiadoro

• Main Authors: Bosa, Silvia, Petti, Marco, Pascolo, Sara
• Format: Conference Proceeding
• Language: English
• Subjects: Beach erosion; Coasts; Dynamics; Numerical models; Oscillations; River flow; Sea currents; Sediment deposits; Sediments; Shallow water; Tidal currents; Waves
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0170793

Sandy beaches frequently undergo erosion processes, which need the construction of coastal protections often also in combination with nourishments to be countered. In particular, nourishment interventions are usually not definitive and they should be repeated almost every year, resulting often economically very onerous for local administrations. In the light of this, an in-depth knowledge of coastal sediments dynamics is desirable as a concrete help to improve planning and management of nourishment interventions, showing, for example, where sediment deposits can be more easily found along the coast. Coastal sediment dynamics is often determined by the mutual interaction of different phenomena, like tidal oscillations and wave motion; also river flow can play a significant role, when the considered area is located close to a river mouth. In this case, sediments are carried by the river towards the sea and they are later redistributed along the coast by tidal currents and wave motion. The sediment dynamics along the coast of Lignano Sabbiadoro in Northern Italy is influenced by the nearby Tagliamento River, the tidal oscillations, and Sirocco and Bora/Levant storms surges, which often alternate during the year. In the present paper, the effects on the sediments dynamics of a medium year are studied by means of a numerical model, which couples an in-house shallow water morphodynamic model and an open source spectral model. The adopted methodology is accurately described, and the results are presented and discussed.