About the project
A 1m rise in mean sea level is almost certain this century (Committee on Climate Change, 2018), but seawalls cannot be built infinitely high. Understanding flooding from wave overtopping is crucial. The PhD will examine bimodal wave interactions that exacerbate overtopping for seasonal beach levels and different coastal protection structures.
Ambitious hazard mitigation plans may protect 400,000 – 500,000 people, but improved forecasting and adaptation to coastal hazards will be essential. Locations around the UK, particularly the South Coast, are exposed to bimodal wave conditions due their position relative to major storm tracks. The interaction of swell and wind waves can significantly modify wave overtopping discharge. Existing predictive tools are limited in their ability to capture these interactions. Validated tools able to interrogate coastal interactions to assess drivers of overtopping are vital to understand present and future flood hazards.
Flume experiments will identify event-scale interactions that trigger multivariate (unimodal and bimodal) wave overtopping hazard at Hayling Island. Past events (from field records) will be examined to assess how bimodal waves interact over a dynamic beach to modify wave runup, prior to exploring the vulnerability of beach fronted structures to bimodal wave overtopping. Industry-standard empirical rules for predicting overtopping hazard (EurOtop) will be adapted to use a spectrum of multivariate wave inputs rather than peak wave conditions. The numerical predictions will be validated using flume/wave-basin observations and used to expand the case study parameter space to consider wave and beach-structure conditions of national interest.
The impacts of changing wave climates, sea level and beach profiles will be simulated to identify future trigger levels in overtopping hazard. The process understanding, climate impacts analysis and new multivariate overtopping tools will be shared with coastal practitioners (e.g., Coastal Partners and the Environment Agency) to support strategic hazard management at local and national scales.
Supervisors
As well as Hachem Kassem and Masashi Watanabe from the University of Southampton, you will also receive supervision from:
- Jenny Brown: jebro@noc.ac.uk from the National Oceanography Centre (lead supervisor).
- Mohammed Shabib Al-Khaldi: mskhaldi@kisr.edu.kw, from the Kuwait Institute for Scientific Research.
Please contact the lead supervisor if you require further information about the project.
References
Modelling shingle beaches in bimodal seas. Development and application of Shingle-B. HR Wallingford Report, RT002, https://coastalmonitoring.org/ccoresources/shingleb/Final_Report_CAS1227-RT002-R01-00.pdf.
Yelland, Brown, et al. 2023 A system for in-situ, wave-by-wave measurements of the speed and volume of coastal overtopping. Communications Engineering, https://doi.org/10.1038/s44172-023-00058-3
Hayling Island Coastal Management Strategy Coastal Processes Study. 2020 https://coastalpartners.org.uk/static/media/resources/appendix-a-coastal-processes-report-draft.pdf
