Tidal Hydrodynamics of a Micro-tidal, Wave Dominated Flood-tide Delta: Port Stephens, Australia

Estuarine hydrodynamics is an integral component in understanding the physical processes that drive sediment transport pathways in estuarine environments. Tidal circulation is often the dominant or key secondary force driving estuarine hydrodynamics. This paper characterizes the tidal circulation patterns over a flood-tide delta in a micro-tidal, wave dominated estuary on the east coast of Australia. This study analyses 13 months of data collected from nine locations throughout the flood-tide delta using two bottom-mounted Acoustic Doppler Current Profilers. Depth-averaged current velocities and durations, along with tidal harmonics are used to characterize the nine sites as either ebb or flood dominant. The two sites closest to the entrance exhibit ebb dominance with the remaining seven sites within the estuary showing flood dominant velocities and longer flood durations. This characterisation is an important precursor to the quantification of sediment transport in these systems and the resulting morphological evolution. An understanding of the processes affecting flood-tide delta morphology and adjacent estuarine beaches is critical to the management of the intrinsic, recreational and commercial value of these environments.