The history and future of coastal inundation in Sydney, NSW. — Australian Meteorological and Oceanographic Society
  1. Schedule
  2. Afternoon Tea + Poster Session 2
  3. The history and future of coastal inundation in Sydney, NSW.

The history and future of coastal inundation in Sydney, NSW. (#2042)

Ben Hague 1 2 , Shayne McGregor 2
  1. Bureau of Meteorology, Docklands, VIC, Australia
  2. School of Earth Atmosphere and Environment, Monash University, Clayton, VIC, Australia

Coastal inundation occurs due to a combination of tidal, atmospheric and oceanic factors. However, there is a global pattern of regular tidal inundation (i.e. coastal inundation caused solely by tidal factors) emerging as mean sea levels rise and cause high tide levels to surpass inundation thresholds (e.g. Ghanbari et al. 2019, Sweet et al. 2018). These events can cause disruptions to local economies and populations (e.g. Hino et al. 2019). To date, the risk that tidal inundation poses to Australia in the future has not been assessed within an impact-based framework. The high population and high-value coastal assets at risk in Sydney provide clear motivation for this work. In addition, the high spatial and temporal sea level data availability, including the 104-year Fort Denison record, makes Sydney an ideal candidate for a first-pass assessment of future tidal inundation risk in Australia.

By collating many historical and contemporary reports of coastal inundation we define regional impact-based thresholds corresponding to different severity of impacts following the methodology of Hague et al. (2019). Applying these thresholds to the Fort Denison sea level record yields a 104-year history of coastal inundation in the Sydney region. Furthermore, we assess the emergence times and probabilities of regular (e.g. monthly, weekly, daily) coastal inundation in the Sydney region under various sea level rise scenarios and provide motivation for a national assessment of coastal inundation risk under a changing climate.

  1. Ghanbari, M., Arabi, M., Obeysekera, J. and Sweet, W. 2019. A coherent statistical model for coastal flood frequency analysis under nonstationary sea level conditions. Earth's Future, 7, 162–177. DOI: 10.1029/2018EF001089
  2. Hague, B., Murphy, B., Jones, D. and Taylor, A. 2019. Impact-based thresholds for extreme sea levels and the emergence of tidal inundation in Northern Australia, Oral Presentation, AMOS-ICTMO Conference 2019, Darwin.
  3. Hino, M., Belanger, S. T., Field, C. B., Davies, A. R. and Mach, K. J. 2019. High-tide flooding disrupts local economic activity. Sci. Adv., 5, DOI: 10.1126/sciadv.aau2736
  4. Sweet, W., Dusek, G., Obeysekera, J. and Marra, J. J. 2018. Patterns and Projections of High Tide Flooding Along the U.S. Coastline Using a Common Impact Threshold. NOAA Technical Report NOS CO-OPS 086, pp.56
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