Hydrodynamic model predictions of tidal asymmetry and observed sediment transport paths in Morecambe Bay

This paper represents results on the sediment transport regime in Morecambe Bay and investigates the connection between this transport regime and the tidal asymmetry in the region. A numerical model of Morecambe Bay is described and varied against current meter and OSCR HF radar data. Sand transport paths from a previously unpublished field study are presented and compared with model predictions of the direction of tidal asymmetry. This reveals a close correlation between the two, indicating that tidal transport plays a dominant role transporting sediment in Morecambe Bay and that the direction is controlled by the asymmetry between flood and ebb tides. Further analysis based on the model predictions examines the relative contribution that the tidal residual and higher tidal harmonics make in determining the direction of tidal asymmetry.