Wave runup (swash) spectra on natural beaches: Morphodynamic controls

摘要: This paper provides insight into the spectral signatures of wave runup (swash) from contrasting beach types; their nature and range morphodynamic controls exerted by morphology exposure. An extensive field data set is used covering full micro-tidal types (reflective, intermediate dissipative), includes gradients ranging approximately 1:6 to 1:60 exposed offshore significant heights 0.5 m 3.0 m. The investigated here consists 187 individual swash spectra. ratio energy in short (f > 0.05 Hz) infragravity < frequency bands found be significantly different between three types. Swash at frequencies dominant on reflective beaches dissipative beaches; consistent with previously reported for surf zone these spectra were classified using an automated algorithm known as CLARA five classes. ordered classes represent evolution spectrum shape described a downshifting peak short-wave band increase level compared level. A universally common feature all beach-states was f-4 roll-off band. In contrast broadly uniform appearance across beach-states, highly variable. conceptual model under increasing decreasing incident level, due consideration morphology, proposed.