Infragravity waves - propagation, dissipation and sediment transport in the inner surf zone of a low sloping beach.

Abstract

Although infragravity waves are known to be important to beach and dune erosion, several aspects of infragravity-wave dynamics are not well understood. As an example, existing field and laboratory data indicates that infragravity waves dissipate energy in the very-shallow nearshore (Van Dongeren et al., 2007). Several dissipation mechanisms have been put forward, but there is few field evidence supporting either of these hypotheses. Furthermore, the role of the infragravity wave in suspension and transport of sediment is not well understood. In this master thesis, observations of infragravity waves are presented, all data gathered during a fieldcampaign on the wadden island Ameland (on a low sloping beach). It discusses how the infragravity waves propagate and dissipate their energy, which is shown to be due to breaking of the wave. Furthermore, it shows that infragravity waves play an important role in the suspension of sediment, and transport of sediment during high energy conditions.