Location: Victoria, Australia
Type of Project: Climate Change Modeling
Client: EPA, Victoria
Left: Residual current velocities near the entrance to western Port. Right: Hypersaline conditions in Port Phillip Bay as a result of climate change.
ASR Ltd were commissioned to investigate the effects of predicted climate change scenarios on Port Phillip Bay and Western Port.
Climate change scenarios were investigated using a fully integrated and calibrated suite of receiving water quality models of Port Phillip and Western Port. The models were 3 dimensional, fully stratified by temperature and salinity and driven by sea level, salinity, air temperature, humidity, barometric pressure, solar radiation, cloud cover and sea surface temperature boundary conditions. Climate change and future growth scenarios incorporate 2030 and 2070 projections for rainfall and evaporation in the Melbourne region.
Two year long hydrodynamic models were run using altered boundary conditions reflecting predicted climate change. The models were coupled with 3DD Lagrangian modeling software to investigate changes in Nutrients (Total Nitrogen and Total Phosphorous), Chlorophyll-a, Suspended Solids, Salinity, Toxicants, Pathogens and Litter as well as flushing times of the bays.
Models were compared between wetter conditions from the 1990’s and projected dry conditions for 2030 and 2070, and mark a 2-3 PSU shift in salinity conditions from hyposaline (less salty than ocean) to hypersaline (more salty than ocean) which significantly alters the circulation and flushing of the bay.
Models indicated significant enhancements in nutrients leading to substantial changes in Chl-a levels. Dispersion modeling also showed reduced river loadings can be expected to increase the coastal concentration of pollutants near the discharge points and a subsequent downstream decrease in concentrations.« Download Project PDF