Coastal management case study - Scarborough, UK

Think

Starter

Watch this video clip that shows wave activity in Sandsend, a small coastal town on the Yorkshire coast (UK) not far from Scarborough. Brainstorm the problems that these sort of events cause and any solutions you can think of.

Write

Activities

Think

Where are the coastal defences?

Scarborough is a town on the North Sea coast of North Yorkshire, England with a population of around 50,000. Scarborough is the largest holiday resort on the Yorkshire coast.

The most striking feature of the town's geography is a headland pointing eastward into the North Sea which separates the sea front into a North Bay and a South Bay.

In 1896 the Council decided to link the two bays by the construction of a 1200 metre link road to be known as Marine Drive. At the time there was much support for the project, not only for the commercial advantages but also due to the pressing need to prevent coastal erosion.

  1. Describe the location of Scarborough, UK.
  2. Describe the location of the coastal defences within Scarborough.
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When were the coastal defences built?

The 22 month coastal protection project began in April 2002. It arose from a Coastal Defence Strategy undertaken by Scarborough Borough Council in 1998, which identified a prioritised action plan for the whole of the town’s coastal frontage.

  1. When was the coastal defence project finished?
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Why were the coastal defences built?

The limited residual life of the existing coastal defence structures which were built in the 19th to early 20th century. There was severe erosion at the toe of the wall which threatened to undermine the seawall and the road. There was regular and costly damage to the infrastructure of Marine Drive, with the concrete in the seawall deteriorating and extensive rehabilitation required.

Severe wave overtopping from the near vertical sea walls causes regular closure of Marine Drive, usually more than 35 times a year. This has a economic impact for local businesses.

Renewed cliff foot erosion would increase the risk from landslides on the headland. Landslides from the Scarborough Castle Headland have been common through history and indeed over a period of 700 years the site of Scarborough Castle had dwindled from 60 acres to 16 acres due to erosion.

Threat to public safety and assets. The resulting threat to public safety and protected assets (estimated at approximately £100m) was considerable.

  1. Give four reasons why coastal defences needed to be built along the Castle Headland.
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What coastal defences were built?

Marine Drive - Sea Wall, Rip-Rap and Accropodes
  • £25.7 million coastal protection project.
  • 11,000 metres square of concrete ‘boardwalk’ style paving has been provided to form a new promenade around Marine Drive.
  • A 1 metre high concrete wave return wall has been cast along the frontage.
  • Scarborough Council determined that the provision of an Accropode revetment with a 1m high wave return wall would allow for overtopping to be reduced significantly, thus significantly reducing the risk of damage to Marine Drive and greatly enhancing the safety of its users.
Scarborough Accropodes
  • Accropodes – interlocking concrete rock armour units.
  • Up to 4,000 are being were to protect the East Pier and Castle Headland. They were pre-cast in Sunderland, then brought to Scarborough in barge loads of 40 at a time.
  • Each Accropode weighs about 15 tonnes.
  • These interlocking units are lighter than rip-rap and therefore can be used at a steeper gradient. Accropodes also have a greater percentage of voids and for given wave conditions overtopping is less.
  • They have a stronger visual impact than rock armour but this is significantly offset by the smaller profile of an Accropode armoured bund.
  • Lower cost than rip-rap.
  • Greater stability and lower maintenance.
  • Design life of at least 50 years.
North Bay Rock Armour - ready to be put in position
  • 280,000 tonnes of granite from Larvik, Norway to act as rock armour (rip-rap).
  1. Describe a ’concrete wave return wall’ and how it works as a coastal defence.
  2. What is an Accropode?
  3. Why are Accropodes considered to be ‘better’ than normal rip-rap?
  4. If Accropodes are so good why was rip-rap still used as part of the Scarborough coastal defence scheme?
  5. Why did the rip-rap come from Norway?
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Who built the coast defences and who paid for them?

Coast Protection Scheme Information Board
  1. Who built the coast defences and who paid for them?
  2. Consider the following individuals and the opinion that they might have about the building of the Scarborough coastal defences. You should explain the opinion that you think these people would have and the reasons behind it. You should mention any concerns that these people map have about the future of the project.
    • The owner of a hotel on South Bay.
    • A member of Scarborough Council.
    • A café owner on North Bay.
    • A Scarborough resident that lives in the west of the town and works in a local factory.
    • A local fisherman.
    • The local police officer.
Review

Review

Using the resources above produce an outline of an answer to the following exam style question:

What strategies can be put in place to control the impact of wave erosion upon human activity. You should give examples from an area you have studied. [8 Marks]


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