The effect of tidal range and mean sea-level changes on coastal flood hazards at Lakes Entrance, south-east Australia
Despite being well-documented in other countries, the roles that anthropogenically induced changes and natural variability in tidal processes play in modulating coastal flood frequencies have not been investigated in Australia. Here we conduct a brief assessment of changes in tidal variability aroun...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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CSIRO Publishing
2023-01-01
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| Series: | Journal of Southern Hemisphere Earth Systems Science |
| Subjects: | |
| Online Access: | https://www.publish.csiro.au/es/pdf/ES22036 |
| _version_ | 1797738247306084352 |
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| author | Dörte Jakob Mitchell T. Black Stefan A. Talke Rodger B. Grayson Ben S. Hague |
| author_facet | Dörte Jakob Mitchell T. Black Stefan A. Talke Rodger B. Grayson Ben S. Hague |
| author_sort | Dörte Jakob |
| collection | DOAJ |
| description | Despite being well-documented in other countries, the roles that anthropogenically induced changes and natural variability in tidal processes play in modulating coastal flood frequencies have not been investigated in Australia. Here we conduct a brief assessment of changes in tidal variability around Australia. We then apply a simple attribution framework to quantify the separate and joint effects of tidal range changes and increasing relative mean sea level on nuisance flood frequency at the location with the largest relative changes in tidal range, Lakes Entrance, Victoria. To understand how these changes in variability affect flood hazards, we consider a nuisance flood threshold based on recent coastal flood impact surveys. Results show that increases in the heights of high tides over recent years have exerted a large influence on coastal flood frequencies. These recent changes are potentially linked to changes in channel dredging regimes. We show that 93% of nuisance flood days since 2009 would not have occurred without these tidal range changes or the coincident increases in the mean sea level. We demonstrate the importance of considering tidal processes in estuarine coastal flood hazard assessments for future planning, even if these processes do not represent a substantial flood threat today. We discuss the implications of this study for future work on estuarine flood hazards and the benefits of considering impact-based thresholds in the assessment of such hazards. |
| first_indexed | 2024-03-12T13:41:04Z |
| format | Article |
| id | doaj.art-46f28a25670f477f8f18ac1f6558d121 |
| institution | Directory Open Access Journal |
| issn | 2206-5865 |
| language | English |
| last_indexed | 2024-03-12T13:41:04Z |
| publishDate | 2023-01-01 |
| publisher | CSIRO Publishing |
| record_format | Article |
| series | Journal of Southern Hemisphere Earth Systems Science |
| spelling | doaj.art-46f28a25670f477f8f18ac1f6558d1212023-08-23T18:45:54ZengCSIRO PublishingJournal of Southern Hemisphere Earth Systems Science2206-58652023-01-01732116130ES22036The effect of tidal range and mean sea-level changes on coastal flood hazards at Lakes Entrance, south-east AustraliaDörte Jakob0Mitchell T. Black1Stefan A. Talke2Rodger B. Grayson3Ben S. Hague4Bureau of Meteorology, Melbourne, Vic., Australia.Bureau of Meteorology, Melbourne, Vic., Australia.Department of Civil and Environmental Engineering, California Polytechnic State University, San Luis Obispo, CA, USA.Retired. Formerly at Department of Infrastructure Engineering, The University of Melbourne, Parkville, Vic., Australia.Bureau of Meteorology, Melbourne, Vic., Australia; and School of Earth Atmosphere and Environment, Monash University, Clayton, Vic., Australia.Despite being well-documented in other countries, the roles that anthropogenically induced changes and natural variability in tidal processes play in modulating coastal flood frequencies have not been investigated in Australia. Here we conduct a brief assessment of changes in tidal variability around Australia. We then apply a simple attribution framework to quantify the separate and joint effects of tidal range changes and increasing relative mean sea level on nuisance flood frequency at the location with the largest relative changes in tidal range, Lakes Entrance, Victoria. To understand how these changes in variability affect flood hazards, we consider a nuisance flood threshold based on recent coastal flood impact surveys. Results show that increases in the heights of high tides over recent years have exerted a large influence on coastal flood frequencies. These recent changes are potentially linked to changes in channel dredging regimes. We show that 93% of nuisance flood days since 2009 would not have occurred without these tidal range changes or the coincident increases in the mean sea level. We demonstrate the importance of considering tidal processes in estuarine coastal flood hazard assessments for future planning, even if these processes do not represent a substantial flood threat today. We discuss the implications of this study for future work on estuarine flood hazards and the benefits of considering impact-based thresholds in the assessment of such hazards.https://www.publish.csiro.au/es/pdf/ES22036astronomical tideschannel dredgingclimate changecoastal floodingcoastal oceanographycompound flooding |
| spellingShingle | Dörte Jakob Mitchell T. Black Stefan A. Talke Rodger B. Grayson Ben S. Hague The effect of tidal range and mean sea-level changes on coastal flood hazards at Lakes Entrance, south-east Australia Journal of Southern Hemisphere Earth Systems Science astronomical tides channel dredging climate change coastal flooding coastal oceanography compound flooding |
| title | The effect of tidal range and mean sea-level changes on coastal flood hazards at Lakes Entrance, south-east Australia |
| title_full | The effect of tidal range and mean sea-level changes on coastal flood hazards at Lakes Entrance, south-east Australia |
| title_fullStr | The effect of tidal range and mean sea-level changes on coastal flood hazards at Lakes Entrance, south-east Australia |
| title_full_unstemmed | The effect of tidal range and mean sea-level changes on coastal flood hazards at Lakes Entrance, south-east Australia |
| title_short | The effect of tidal range and mean sea-level changes on coastal flood hazards at Lakes Entrance, south-east Australia |
| title_sort | effect of tidal range and mean sea level changes on coastal flood hazards at lakes entrance south east australia |
| topic | astronomical tides channel dredging climate change coastal flooding coastal oceanography compound flooding |
| url | https://www.publish.csiro.au/es/pdf/ES22036 |
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