The Victorian Coastal Monitoring Program multi-method historical shoreline analysis of Port Phillip Bay

McCarroll J1,2, Ferns L1, Kennedy D2, Allan B3, Sorrell K2, Quang Tran H4,5, Pucino N3, Ierodiaconou D3

1Environment and Climate Change; Department of Environment, Land, Water and Planning,

2School of Geography, The University of Melbourne,

3School of Life and Environmental Sciences, Deakin University,

4Faculty of Engineering and Information Technology, The University of Melbourne,

5Metocean Solutions – a division of Metservice

Abstract:

The shorelines of Port Phillip Bay (PPB), Victoria, are vital areas for biodiversity, public utility, and recreation. Many sections within the bay are highly engineered, with historic ‘hard’ interventions, such as seawalls, and ongoing ‘soft’ interventions, in the form sand renourishments. A key challenge for coastal managers is understanding how this fetch-limited, estuarine coast has behaved in the past and how it is likely to change in future, including in response to engineering interventions and ongoing sea level rise. For this reason, the Victorian Coastal Monitoring Program (VCMP) has been expanded into PPB, including 6 directional wave buoys and 4 additional citizen science drone monitoring sites. In accompaniment to gathering field data, a comprehensive multi-method historical shoreline analysis is being conducted, applied to transects at 50-m alongshore intervals around the bay, including: (i) high-resolution topo-bathymetry for cross-shore profile extraction; (ii) satellite [Digital Earth Australia and CoastSat] and aerial imagery [1930 – present] for determining shoreline change time series’; (iii) hydrodynamic wave model data [SCHISM-WWM3], for calculating wave statistics and potential alongshore sediment flux; and (iv) combined analysis of waves, bathymetry, and shoreline trends to estimate sediment budgets. This work supplements existing analysis of coastal hazards within PPB, improving understanding of how fetch-limited coasts have responded to a combination of natural processes and human interventions. The outputs will be combined with ongoing field observations to calibrate numerical modelling approaches, which will be used to predict multi-decadal shoreline change across the bay.


Biography:

Jak McCarroll is a coastal processes scientist, with the Department of Environment, Land, Water and Planning in Victoria, working on the Victorian Coastal Monitoring Program. Jak’s research interests include coastal geomorphology, rip currents, sediment budgets, headland bypassing, and epithermal gold exploration.