Australasian Coasts & Ports Conference, 2023, Sunshine Coast, Queensland
Urban beaches in semi-sheltered harbor environments are highly valued public spaces that require detailed understanding of coastal dynamics for appropriate management. Understanding the dynamics these environments is challenging due historic management interventions such as renourishment and hard infrastructure. As a result, commonly applied modelling and hazard assessment methods are not necessarily appropriate for semi-sheltered often fetch-limited urban beaches, without site-specific calibration. Show more…This paper focuses on the calibration and potential applications of three different numerical models to better understand coastal processes on the Sandringham Beach in Port Phillip Bay, Victoria. First, the shoreline position model ShorelineS was applied to understand beach rotation, seasonal trends in shoreline movement and long-term rates of shoreline change. Model calibration was informed by monthly monitoring data, including drone-based topographic surveys and wave buoy data. Next, the storm response model XBeach was calibrated using observed wave events and measured changes in the coastal profile. The models were collectively used to give new insight on the beach dynamics at short, medium, and long timescales.
Outputs of the XBeach and ShorelineS modelling were then used to inform variables for projecting shoreface translation to sea level rise using the ShoreTrans model, where the sensitivity to different trajectories of barrier rollover and translation were assessed. Isolating the cross-shore adjustment in ShoreTrans allowed the idealised beach topography to be reconstructed for a sea level rise scenario representing the year 2100. Balance of alongshore sediment flux was achieved by passing volume from profile to profile according to the net sediment balance in the system, informed by long-term rates.
The paper introduces a conceptual a multi-model workflow that is proposed for exploring present day and future scenarios, with application for hazard management and adaptation design. Show less…
