SHORELINE BOUNDARY CONDITIONS FOR WATER WAVE MODELS

The aim of this work is to extend to include the swash zone the solution domain of wave-resolving and wave-averaged depth-integrated numerical models used for simulating the nearshore hydrodynamics. Shoreline boundary conditions are therefore derived and verified for both the two categories of models. For what concerns wave-resolving models, we discuss the applicability of Boussinesq-type equations to model swash zone flows. Therefore the role of the dispersive-nonlinear terms which characterize these equations, is studied on the basis of the Carrier and Greenspan (1958) solution for periodic regular waves. Subsequently a technique suitable to track the movements of the instantaneous shoreline and to impose the correct water depth and velocity at the shoreward limit of the computational domain is introduced. This technique is based on the use of a specific shock-capturing numerical scheme, capable of treating the discontinuity characterizing the shoreline, where a transition between wet and dry conditions occurs. A numerical model based on Boussinesq-type equations is therefore coded and tested. The new boundary conditions are finally implemented in the numerica