Abstract
Energetic swell waves, particularly when they coincide with high water levels, can present significant coastal hazards. To better understand and predict these risks, analysis of the sea levels and waves that generate these events and the resulting coastal impacts is essential. Two energetic swell events, neither of which were predicted by modelled flood forecasts, occurred in quick succession in the English Channel. The first event, on 30 January 2021, produced moderate significant wave heights at or just below the 0.25 year return period along the southwest English coast, but combined with significant swell caused overtopping at East Beach in West Bay and at Chesil Beach. The second event, on 1 February 2021, generated the highest wave energy periods measured at many locations along the southern English coastline and, at high water, caused waves to run up over the promenades at Poole Bay and Christchurch Bay and caused overtopping at Hayling Island. Both events are described in detail, and their spatial footprints are mapped through a joint return period analysis using a copula function. It is found that typical joint return period analysis of water level and significant wave height underestimates potential impacts, while a joint consideration of water level and wave power (P) describes the 31 January event better and a joint consideration of water level and energy period (Te) best describes the 1 February event. Therefore, it is recommended that Te and P are adopted for coastal monitoring purposes, and that future studies further explore the use of both parameters for swell monitoring.
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References
Bernardara, P., Mazas, F., Kergadallan, X., and Hamm, L. 2014. A two-step framework for over-threshold modelling of environmental extremes. Nat. Hazards Earth Syst. Sci. 14: 635–647. doi: https://doi.org/10.5194/nhess-14-635-2014.
Bradbury, A., Mason, T., and Poate, T. 2007. Implications of the spectral shape of wave conditions for engineering design and coastal hazard assessment – Evidence from the English Channel. In 10th International Workshop on Wave Hindcasting and Forecasting and Coastal Hazard Symposium. Available from http://www.waveworkshop.org/10thWaves/ProgramFrameset.htm.
Bradbury, A., Stratton, M., and Mason, T. 2011. Impacts of wave climate with bi-modal wave period on the profile response of gravel beaches. In The Proceedings of Coastal Sediments 2011. Edited by J.D. Rosati, P. Wang, and T.M. Roberts. World Scientific Publishing, Singapore, pp. 2004–2018. doi.org/10.1142/9789814355537_0151.
Carr, A. 1983. Chesil beach: environmental, economic and sociological pressures. Geogr. J. 149: 53–62. doi: https://doi.org/10.2307/633342.
CEFAS. 2021. Available from https://www.cefas.co.uk/data-and-publications/wavenet/ [accessed 12 May 2021].
Coles, S.G. 2001. An introduction to statistical modelling of extreme values. Springer, London, UK. 209 pp.
Datawell. 2020. Datawell Waverider reference manual. Datawell BV. Available from ––https://www.datawell.nl/Portals/0/Documents/Manuals/datawell_manual_dwr-mk3_dwr-g_wr-sg_2020–02–01.pdf.
De Waal, D., and Van Gelder, P. 2005. Modelling of extreme wave heights and periods through copulas. Extremes, 8(4): 345–356. doi: https://doi.org/10.1007/s10687-006-0006-y.
Dhoop, T., and Thompson, C. 2018. Extreme value analysis for NNRCMP coastal wave data. Channel Coastal Observatory. Available from https://coastalmonitoring.org/reports/index.php?link=&dla=download&id=1517&cat=266/Extreme_Value_Analysis_for_CCO_Coastal_Wave%20Data_TN03.pdf.
Di Bernardino, E., Maume-Deschamps, V., and Prieur, C. 2013. Estimating a bivariate tail: A copula based approach. J. Mult. Analys. 119: 81–100. doi: https://doi.org/10.1016/j.jmva.2013.03.020.
Draper, L., and Bownass, T. 1983. Wave devastation behind Chesil beach. Weather, 38: 346–352. doi: https://doi.org/10.1002/j.1477-8696.1983.tb04822.x.
EuroGeographics (Eurostat). 2014. Administrative units 2014. ESRI Shapefile. Available from https://ec.europa.eu/eurostat/web/gisco/geodata/reference-data/administrative-units-statistical-units
EurOtop. 2018. Manual on wave overtopping of sea defences and related structures. An overtopping manual largely based on European research, but for worldwide application. Edited by J.W. Van der Meer, N.W.H. Allsop, T. Bruce, J. De Rouck, A. Kortenhaus, T. Pullen, H. Schüttrumpf, P. Troch, and B. Zanuttigh. Available from www.overtopping-manual.com.
Folley, M. 2016. The wave energy resource. In Handbook of Ocean Wave Energy. Edited by A. Pecher and J. Kofoed. Springer, Cham, Switzerland. pp. 43–79. doi: https://doi.org/10.1007/978-3-319-39889-1_3.
GEBCO Compilation Group. 2019. GEBCO 2019 Grid. doi: https://doi.org/10.5285/836f016a-33be-6ddc-e053-6c86abc0788e.
Hawkes, P.J. 1999. Mean overtopping rate in swell and bimodal seas. Proc. Instn Civ. Engr Wat., Marit. & Energy, 136: 235–238. doi: https://doi.org/10.1680/iwtme.1999.31987.
Hawkes, P.J., Gouldby, B.P., Tawn, J.A., and Owen, M.W. 2002. The joint probability of waves and water levels in coastal engineering design. J. Hydraul. Res. 40: 241–251. doi: https://doi.org/10.1080/00221680209499940.
Li, F., van Gelder, P.H.A.J.M., Ranasinghe, R., Callaghan, D.P., and Jongejan, R.B. 2014. Probabilistic modelling of extreme storms along the Dutch coast. Coast. Eng. 86: 1–13. doi: https://doi.org/10.1016/j.coastaleng.2013.12.009.
Malagon Santos, V., Haigh, I., and Wahl, T. 2017. Spatial and temporal clustering analysis of extreme wave events around the UK coastline. J. Mar. Sci. Eng. 5(28). doi: https://doi.org/10.3390/jmse5030028.
Mason, T., and Dhoop, T. 2017. Quality assurance & quality control of wave data. National Network of Regional Coastal Monitoring Programmes of England. Available from https://coastalmonitoring.org/ccoresources/dataqualitycontrol/QC_Manual_CCO_Waves.pdf.
Mason, T., and Dhoop, T. 2018. Occurrence of bimodal seas around the English coastline. Technical Note TN02.
National Network of Regional Coastal Monitoring Programmes of England. Available from https://coastalmonitoring.org/reports/index.php?link=&dla=download&id=1518&cat=266/Occurrence_of_Bimodal_Seas_around_the_English_Coastline_TN02.pdf.
Mason, T., Bradbury, A., Poate, T., and Newman, R. 2008. Nearshore wave climate of the English Channel - Evidence for bi-modal seas. In Coastal Engineering 2008. Proceedings of the 31st International Conference. Edited by J. McKee Smith. World Scientific Publishing, Singapore. pp. 605–616. doi: https://doi.org/10.1142/9789814277426_0051.
Mazas, F., and Hamm, L. 2017. An event-based approach for extreme joint probabilities of waves and sea levels. Coast. Eng. 122: 44–59. doi: https://doi.org/10.1016/j.coastaleng.2017.02.003.
NNRCMP. 2021. Available from https://coastalmonitoring.org/ [accessed 12 May 2021].
Palmer, R., Nicholls, R.J., Wells, N.C., Saulter, A., and Mason, T. 2014. Identification of ‘energetic’ swell waves in a tidal strait. Cont. Shelf Res. 88: 203–2015. doi: https://doi.org/10.1016/j.csr.2014.08.004.
Poate, T.G., McCall, R.T., and Masselink, G. 2016. A new parameterisation for runup on gravel beaches. Coast. Eng. 117: 176–190. doi: https://doi.org/10.1016/j.coastaleng.2016.08.003.
Serinaldi, F. 2015. Dismissing return periods. Stoch. Environ. Res. Risk Assess. 29: 1179–1189. doi: https://doi.org/10.1007/s00477-014-0916-1.
Sibley, A., and Cox, D. 2014. Flooding along the English Channel coast due to long-period swell waves. Weather, 69: 59–66. doi: https://doi.org/10.1002/wea.2145.
Sklar, A. 1959. Fonctions de repartition à n dimensions et leurs marges. Publications de l’Institut Statistique de L’Université de Paris. 8: 229–230.
Wahl, T., Mudersbach, C., and Jensen, J. 2012. Assessing the hydrodynamic boundary conditions for risk analyses in coastal areas: a multivariate statistical approach based on copula functions. Nat. Hazards Earth Syst. Sci. 12: 495–510.
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Dhoop, T., Thompson, C. Swell wave progression in the English Channel: implications for coastal monitoring. Anthropocene Coasts 4, 281–305 (2021). https://doi.org/10.1139/anc-2021-0008
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DOI: https://doi.org/10.1139/anc-2021-0008