Modelling the impact of climate change and anthropogenic modifications on estuary entrances in southeastern Australia

Description:

This project aims to model estuary entrances in southeastern Australia and test and simulate a range of climatic scenarios as well as types of anthropogenic modifications. Models would be setup for a range of sites in the region which contrast in terms of their physical setting, for example mesotidal versus microtidal, high wave energy versus moderate wave energy and large river catchment versus small. The project would first evaluate the different types of model available for this purpose, choosing the most appropriate and efficient one for adoption in the project. The model would be trained using available datasets, including high-resolution terrain, wave climate, river discharge and tidal water level changes. A range of climate scenarios would be tested, including adding certain amounts of sea-level rise derived from the latest modelling for the region, changing the nature of river discharge accounting for increased rainfall or increased aridity according to climate modelling. Modelling would explore the resulting changes to the estuary entrance caused by these variations to the model and the subsequent impacts on the broader estuary. A range of anthropogenic impacts could be simulated including the construction of estuary training walls, sea walls along shorelines adjacent to the estuary entrance and dredging of the estuary channel. Evaluating each of these in turn or a combination would lead to valuable insights into the shifts in entrance regime caused by such interventions. Again, flow-on effects to the broader estuary could be explored, for example, if an estuary entrance is trained, how does the resulting channel scour influence water levels in the estuary due to tidal flows. There is also an opportunity in exploring both climate and anthropogenic changes, to investigate changes to the flooding and inundation potential for low-lying areas around the broader estuary.