Mechanics of Formation of a Nearshore Sand Bar in Ebb-Tidal-Spit: A theoretical Study

Abstract

Numerical model for the tides in the neighbourhood of a growing ebb-spit is described, theoretically, using polar co-ordinates. This model avoids the numerical difficulties associated with corners and allows the use of an idealised submarine topography in interpreting the dynamics of formation of a bar. The model derives the well known tidal characteristics for the ebb-spit and gives confidence in applying this technique to further theoretical studies, no longer tied to particular real situations. It is shown that ebb-spits are characterized by strong tidal flows and it is possible that vorticity generated near the ebb-spit plays a key role in the dynamics of nearshore ( 5 m water depth or within zone of surf activity) sand bar.