Overview

Project Highlights:

  • Evaluating ecosystem services (coastal flood protection) provided by sand dune vegetation.
  • Truly multi-disciplinary: linking ecology with geomorphology.
  • Providing data of direct benefit to managing coastal flood risk in the UK.

Coastal areas support high population densities and are the location of significant infrastructure. The proximity to the sea, however, makes them vulnerable to coastal flooding. These impacts are predicted to get worse in the future due to sea level rise and increased storminess. Coastal ecosystems can provide significant flood protection, which might mitigate some of these climate change impacts. Our understanding of the degree of protection provided by coastal ecosystems is, however, incomplete and very variable. Soft coast habitats such as saltmarsh have received considerable research interest with respect to which factors mediate the quantity of sea defence provided. However, coastal dunes have received very little interest, even though they provide the first line of coastal defence for considerable stretches of UK coastline.

It is assumed that vegetated dunes provide better coastal defence than unvegetated dunes (Barbier et al. 2008), yet the evidence for this is largely untested and is extrapolated from a single restoration study in France (Roze & Lemauveil 2004). This is based on a very simple statistical model based on the predicted relationship between vegetation and dune height and so flood protection. However, while vegetation on dunes may play a role in building dune height, or slowing the erosion rate of frontal dunes during storm events, other factors such as the morphology of the dune, e.g. width of dune, the sand volume contained, and the width of the whole dune system behind are also likely to govern the sea defence function of coastal dunes. These factors are not currently considered in the flood protection function of sand dune systems.

This PhD will combine ecological and geomorphological measurements to test the model presented by Barbier et al. (2008) using a range of natural and artificially engineered dune systems at local (sub-sediment cell) and regional (whole sediment-cell) scales. It will explore whether the amount and type of dune vegetation on frontal dunes increases the amount of coastal defence service the dunes provide, and will measure the relative contribution of vegetation compared with other geomorphological factors. The student will use these data to construct a statistical model linking geomorphology, vegetation and environmental factors to the extent of the defence function. Specifically, this PhD will answer the following questions:

  1. What is the empirical relationship between sand dune vegetation cover, dune morphology and the coastal defence function of dunes?
  2. What is the coastal defence value of UK sand dunes?
  3. How will the coastal defence value of UK sand dunes change in the future?
Sand dune foreland on Lincolnshire coast, showing scarp (on right of picture) that resulted from a large storm surge. The dunes prevented inland flooding from this.

Methodology

The student will undertake fieldwork at a range of sites (e.g. Northumberland, Lincolnshire or Norfolk on the UK east coast; North Wales on the west coast), to measure sand dune morphology and relate this to vegetation cover and type, and storm damage. They will then use existing regional scale data, e.g. LiDAR and aerial photography to determine the relationship between dune vegetation, dune geomorphology and the coastal defence function of dunes. Finally, the student will construct a statistical model to predict and map the role of vegetation in the coastal defence function of UK dunes, and predict their potential sensitivity to future storm events.

Training and Skills

CENTA students are required to complete 45 days training throughout their PhD including a 10 day placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to CENTA research themes. 

The student will receive training in geomorphological techniques, vegetation surveying, fieldwork and statistical approaches. They will develop skills identified by NERC as ‘most wanted’ for working in the environment sector, such as multi-disciplinarity, fieldwork and field observation.

Timeline

Year 1 student will collate the evidence on the relationship between dune vegetation and dune morphology, and between dune morphology and flood protection, across multiple dune systems. They will use this evidence to develop a set of measurements to establish the empirical relationship between these factors.

Year 2 Secondary data will be collated and relevant indices will be extracted relating to the measures and relationships found in year 1. These will be validated by relating dune morphology to coastal erosion at additional sites, including the Netherlands.

Year 3 Students will use the data from years 1 and 2 to model and map the coastal defence function of UK dunes and how predicted sea level rise and storm frequency and severity under climate change will affect this.

Partners and collaboration (including CASE)

This student will work closely with Dr Laurence Jones at the Centre for Ecology and Hydrology in Bangor. This provides the potential for excellent cross-over between the fundamental (at Loughborough University) and applied (at CEH, Bangor) aspects of the project. There is also the exciting possibility of working with Dutch collaborators on artificially engineered dune coastal defences in the Netherlands. There is also the possibility of working with a range of government and non-government agencies such as Natural England and the Environment Agency. Many of the dune systems are managed by these organisations, and the supervisory team has considerable experience working alongside these organisations.

Further Details

For information about this project, please contact Dr Jonathan Millett (j.millett@lboro.ac.uk). For enquiries about the application process, please contact Susan Clarke, Department of Geography, Loughborough University (S.N.Clarke@lboro.ac.uk).

Please quote CENTA when completing the application form: http://www.lboro.ac.uk/study/apply/research/.