Hydrodynamics of Darwin Harbour

Abstract

Although macrotidal, Darwin Harbour is poorly flushed, especially in the dry season when the residence time in the upper reaches is of the order of 20 days. Much of the riverine fine sediment remains trapped in mud flats and mangroves with little escaping to the sea. The complex bathymetry of headlands and embayments generate complex currents comprising jets, eddies, and stagnation zones that can trap pollutants inshore. The tidally averaged circulation may control the location of the sand banks, indicating a feedback between the bathymetry and the water circulation. The environment in Darwin Harbour has the potential to degrade and the water circulation in the harbour must be considered when planning developments.