Shoreline Implications of Flood-Tide Delta Morphodynamics: The Case of Port Stephens (SE Australia)

Flood-tide deltas are dynamic features that are linked to the morphodynamics of the associated estuarine beaches and shorelines. Flood-tide delta morphodynamics remain largely unknown. Historic aerial photographs from Port Stephens, a ria-like estuary located in NSW (Australia), are analysed using Geographic Information System (GIS) techniques. Port Stephens is used as a case study to define flood-tide delta morphodynamics that will be applicable to similar systems elsewhere. The waterline is chosen to represent the evolution of the estuarine beaches because they are reflective in a microtidal environment. Boundary definition for the flood-tide delta needs further work since it is a submerged feature and the photographs have different quality and correspond to different tidal levels. It is suggested that image processing techniques may help to solve this problem in the future. More studies, both morphologic and hydrodynamic, are needed to establish the sediment paths and magnitudes within the Port Stephens flood-tide delta.