Swash bar dynamics on a high-energy mesotidal beach

Swash bar dynamics can be an important constituent of beach dynamics, playing a significant role in post storm recovery of displaced beach systems. However, their low amplitude and dynamic nature make them difficult to monitor and thus challenging in terms of unravelling their evolutionary patterns. This study makes use of sensitive measurement techniques to measure fine scale (vertical) changes of an advancing swash bar over several tidal cycles. The coincidence of moving from neaps to springs in this period, alongside a relatively steady set of wave conditions, highlighted the high importance of tidal stage level in controlling swash bar dynamics. A high resolution shallow water wave model (SWAN) was also run with the empirical measurements of wave and beach response to produce wave force (on seabed) predictions over the swash and trough zones of the beach. The latter showed a close correlation between model results and bed response.