Rock Armour: A Flexible Approach to Coastal Protection

Rock armour is a widely used coastal defense technique along the Holderness Coast, offering a more flexible alternative to traditional sea walls.

Definition: Rock armour consists of large boulders dumped at the foot of a cliff to force waves to break and absorb their energy.

Key characteristics of rock armour:

• Material: Large, often angular boulders
• Placement: Typically transported by barge and placed at the cliff base
• Design: Not secured to the ground, allowing for movement that absorbs wave energy

Advantages of rock armour:

1. Relatively cheap and easy to maintain (£1,000-4,000 per meter)
2. Can be used for fishing, providing additional benefits
3. Flexible and adaptable to changing conditions

Disadvantages:

1. Can be expensive to import suitable rock
2. May block views and access to the beach
3. Often doesn't match the local geology, impacting landscape aesthetics

Example: Withernsea's rock armour installation, costing £6.3 million, demonstrates the significant investment required for this type of coastal defense.

The use of rock armour along the Holderness Coast illustrates the ongoing challenge of balancing effective coastal protection with environmental and aesthetic concerns. Its implementation in various locations provides valuable insights into the long-term efficacy of this approach in managing coastal erosion.

The Holderness Coast: An Overview of Erosion and Coastal Processes

The Holderness Coast is a prime example of rapid coastal erosion in action. Located on the east coast of the UK, this stretch of coastline faces significant challenges due to its unique geographical and geological characteristics.

Highlight: On average, over 2 metres of the Holderness coastline is lost every year, with 4 km of land and 29 villages lost since Roman times.

Several factors contribute to the coast's vulnerability to erosion:

1. Long fetch: The coast is exposed to winds and waves from the northeast, with a fetch of 500-800 km.
2. Powerful currents: Atlantic currents circulating into the North Sea enhance wave energy.
3. Low-pressure weather systems: Intense storms generate huge waves.
4. Deep sea floor: Waves maintain their energy until they reach the cliff base.

Vocabulary: Fetch refers to the distance over which wind blows across open water, affecting wave size and energy.

These factors combine to create a highly dynamic and erosive coastal environment, making the Holderness Coast a critical area for studying coastal processes and management strategies.