National Network of Regional Coastal Monitoring Programmes

Gravel Coasts

Beach and barrier systems with a dominant gravel fraction, including ‘pure’, ‘compound’ and ‘mixed sand-gravel’ systems are common in the UK and throughout the world.

Seaton Cliffs at Mason's Cave in conglomerate and sandstone of the Burnside Sandstone Formation (Stratheden Group) with storm beach ridges in coarse gravel. Source British Geological Survey ImBase ref P638726.

Mixed sand gravel at Shanklin Chine. Source National Oceanography Centre.

Composite beach at Fairbourne. Source National Oceanography Centre




It is generally accepted that gravel barrier shorelines offer widespread, critically important natural flood protection to many coastal communities. Moreover, their creation and enhancement are increasingly seen as sustainable and nature-based adaptation options that boost natural capital. But these assets must be well managed to ensure they continue serving such functions in the face of increased risk of coastal erosion and flooding. At present our understanding and modelling capability of gravel beach and barrier dynamics significantly lags behind that of their sandy counterparts

NERC Highlight Topics

Projects responding to the 2023 NERC Special Highlight Topic F: ‘Building understanding of natural coastal protection by gravel barriers in a changing climate’, were selected to address the following six research questions:

  1. How do decadal scale morphodynamics of gravel barriers respond to changes in sea level, storminess and sediment supply, and influence coastal evolution? How will this impact on the ecosystems they support?
  2. Under future climate change, will the coastal protection role of gravel barriers be compromised, potentially triggering management interventions?
  3. When and how does sediment transport on gravel barriers differ from the better studied sand cases?
  4. What is the internal structure and composition of gravel beaches, and how do variations in composition influence beach morphology and dynamics?
  5. What is the role of hydraulic conductivity in influencing barrier behaviour?
  6. Can we quantify the critical interactions between gravel barriers and the back-barrier environment (marsh, lagoon, estuary), as well as the interplay between gravel barriers and coastal structures?

NERC Highlight Topics

Increasing our understanding of gravel barrier dynamics to develop practical management tools, see project details.

UKGravelBarriers

Delivering a new community modelling system coupled with terrestrial, marine and groundwater sectors to produce numerical simulations which can be used to support multi-hazard analyses under present and future climate change scenarios. These deliverables will be combined with an assessment of the role of coastal habitats, resulting in national maps for protective services and vulnerabilities of coastal habitats to climate-driven multi-hazards. We will also provide tools to analyse the efficacy of future coastal management schemes. See project details.

Category:Understanding coastal protection by gravel barriers in a changing climate

This Wiki will disseminates the findings of BGS research and facilitates the open exchange of information within the broader geological community.

This dedicated Wiki site will be used to update our current understanding on the six questions addressed by the 2023 NERC Highlight topic.

coming later this year

data being collected at present