Following on from the original gravel beach BARDEX experiment, BARDEX II aims to collect a comparable data set, but this time from a sandy barrier. This new data set is not only highly relevant in providing direct comparison with the gravel barrier data set (thereby providing added value to BARDEX), but the sandy barrier data will also be important in its own right by providing fundamental new information on cross-shore sediment transport processes in the nearshore zone that arise from the sandy nature of the substrate. Specifically, in addition to explicitly addressing the effect of swash/groundwater interactions to sediment transport and morphological development in the swash zone, we will also investigate the sediment exchange between the swash and surf zone and, related, the dynamics of nearshore bar systems. It is generally accepted that mean offshore-directed flows are responsible for beach erosion and offshore bar migration under energetic wave conditions, but there is considerable debate in the literature as to what causes beach accretion and onshore bar migration under calm wave conditions. There have been a number of processes proposed that may be implicated in onshore sediment transport and bar migration, including: (1) onshore mass flux due to cell circulation (Aagaard et al., 2006); (2) sediment stratification (Falchetti et al., 2010); (3) turbulence associated with breaking waves and bores (Butt et al., 2004); (4) cross-shore velocity skewness (vertical wave asymmetry; Marino-Tapia et al., 2007); (5) cross-shore velocity acceleration skewness (vertical wave asymmetry; Hoefel and Elgar, 2003); (6) ventilated boundary layer (Conley and Inman, 1992); and (7) plug flow due to horizontal pressure gradients (Foster et al., 2006). These different processes are not necessarily mutually exclusive and all will be addressed during BARDEX II.
BARDEX2 was a prototype-scale experiment designed to invertigate barrier beach dynamics under a wide range of wave and water level conditions.
Multiple findings published in a special issue of Coastal Engineering
|Effective start/end date||2/01/12 → 31/03/14|