PhD: Developing understanding of flood hazard from bimodal wave overtopping

University of Southampton

Southampton, UK 🇬🇧

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   

Potential supervisors

Lead supervisor

Dr Hachem Kassem PhD, MSc, FHEA

Lecturer

Research interests
  • Nearshore hydrodynamics and coastal sediment dynamics
  • Coastal and ocean engineering and flow-structure-seabed-biota interactions
  • Adaptive, nature-inclusive solutions to climate-mediated geohazards, including flooding, erosion and habitat degradation

Supervisors

Dr Masashi Watanabe

Lecturer B in Coastal Marine Science

Research interests
  • Modelling ocean and coastal processes
  • Coastal geomorphology
  • Coral reefs

Entry requirements

You must have a UK 2:1 honours degree or higher in a relevant subject. You can also have its international equivalent.

We are looking for:

  • You should be highly numerate, with a good understanding of coastal processes and able to communicate with the various project partners.

You will have the opportunity to use prototype-scale experimental facilities and will be trained by the supervisory team to develop further skills and knowledge.  

If English is not your first language, you will need an International English Language Testing System (IELTS) overall score of 6.5, with a minimum of 6.0 in all components. Visit our English language proficiency pages to find out about other qualifications we accept.

Fees and funding

For UK students, the studentship covers UK fees, plus a stipend of £20,780 (UKRI Standard rate) tax-free per annum for up to 3.5 years.

How to apply

Apply for full-time study

Apply for part-time study

 You need to:

  • add the project title under ‘Topic or field of research proposed’
  • add your supervisor in section 2

 Applications should include:

  • 1 page statement of your research interests in flooding and FLOOD-CDT and your rationale for your choice of project
  • CV (resumé) giving details of your academic record and stating your research interests
  • two current academic referees together with institutional email addresses
  • academic transcripts and d​egree certificates (translated if not in English) – if you have completed both a BSc and an MSc, we require both.
  • English language qualification (if applicable)

Contact us

Faculty of Environmental and Life Sciences

If you have a general question, email our doctoral college: fels-pgr-apply@soton.ac.uk.

Project leader

For project specific queries, email the lead supervisor Professor Jenny Brown: jebro@noc.ac.uk.

28 days remaining

Apply by 8 January, 2026

POSITION TYPE

ORGANIZATION TYPE

EXPERIENCE-LEVEL

DEGREE REQUIRED

IHE Delft - MSc in Water and Sustainable Development