Infragravity swash parameterization on beaches: The role of the profile shape and the morphodynamic beach state

A field campaign was undertaken at Somo beach in northern Spain, with the aim of understanding the processes involved in the generation of low frequency swash. Taking the parameterization presented in earlier studies as a starting point, a novel empirical model was defined based on a database which included datasets from Somo beach and from 9 other experiments. This new parameterization was obtained by relating the horizontal cross shore component of the infragravity swash to the foreshore slope and the morphodynamic beach state through the non-dimensional fall velocity parameter. The role of previous sea states when determining the morphodynamic beach state was also assessed. A strong correlation between low frequency oscillations and the morphology of the beach was verified, resulting in a substantial improvement over existing infragravity swash predictions proposed in the literature.