This project is one of a number that are in competition for funding from the University of Bath URSA competition. Please see the URSA webpage for more information.
Project Background:
Composite beaches consist of a lower foreshore of sand and a naturally occurring permanent or semi-permanent backshore ridge of cobbles, and are ubiquitous beach environments in the UK, USA and NZ. These beaches are known to be highly stable because they combine a dissipative sand slope and a reflective cobble berm, which represent the two most stable end members in the classification of beach morphodynamics. Furthermore, when a permanent cobble ridge exists it can play a significant natural coastal protection role, stabilising the upper beach and providing overtopping protection to the hinterland. As a result, constructed cobble berms (or dynamic revetments) designed to mimic composite beach cobble ridges are being trialled to provide coastal defence at vulnerable beaches on the US West Coast with some success. Despite the common occurrence of composite beaches and their value as a natural form of coastal defence they have received very little attention in academic literature with almost no composite beach-specific studies being undertaken to date. As a result, understanding of composite beach processes such as cross- and longshore cobble transport, wave runup and overtopping of cobble ridges and response to sea level rise is minimal.
Project Aims and Methods:
This project aims to fill this identified research gap and undertake one of the first detailed studies into composite beach behaviour. This work will enhance understanding of this valuable beach type and gain insight which will enable the design nature-based coastal defence structures which mimic composite beach behaviour to provide sustainable and low-cost coastal protection. This will be achieved through the following activities:
- Analysis of existing historical topographic data to elucidate the medium to long-term variability of composite beaches and their resilience to extreme storms and storm sequences. This will include a global assessment of composite beach stability using satellite imagery via the new “CoastSat” satellite coastal monitoring tool.
- Analysis of data from the recently installed (June 2021) permanent Lidar station at Borth beach which provides beach profiles and wave runup data continuously at 1 Hz. This analysis will focus on storm erosion and post-storm response.
- Field experiments using a newly-developed, wave-by-wave cobble tracking methodology at 2 or more composite beaches in Wales and/or USA to better understand the short term variability of composite beach ridges and the mobilisation of individual cobbles.
- Test and potentially develop the existing state of the art XBeach-G coastal model to predict morphology changes on composite beaches. If successful, this will improve our ability to assess the vulnerability of composite beaches to increasing storminess and provide a tool for the design of dynamic revetment coastal protection structures.
Note that while the above activities are proposed, it is envisaged that the successful student will have significant input into the project design as it evolves.
Candidate Requirements
Applicants for a studentship must have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK, in a relevant quantitative subject, e.g. Physical Sciences, Engineering, Geographical Sciences, Engineering, Mathematics, Physical Oceanography. Computer programming, GIS and data analysis skills are desirable. The position involves field work as well as data analysis and use of numerical models.
Training
The project will involve fieldwork in the UK and the USA through collaboration with an ongoing research project at Scripps Institute of Oceanography who are completing a field programme investigating composite beaches in Southern California.
Enquiries and Applications:
Informal enquiries are welcomed and should be directed to Dr Chris Blenkinsopp, [Email Address Removed]
Formal applications should be made via the University of Bath’s online application form for a PhD in Civil Engineering.
- When completing the form, please identify your application as being for the URSA studentship competition in Section 3 Finance (question 2) and quote the project title and lead supervisor’s name in the ‘Your research interests’ section.
More information about applying for a PhD at Bath may be found on our website.
We welcome and encourage student applications from under-represented groups. We value a diverse research environment. If you have circumstances that you feel we should be aware of that have affected your educational attainment, then please feel free to tell us about it in your application form. The best way to do this is a short paragraph at the end of your personal statement.