Coastal management — protecting the coast

Coastlines are under pressure from erosion, sea level rise, and increasing storm intensity. CCEA examiners expect you to describe and evaluate a range of coastal management strategies using a Northern Ireland case study.

Why manage coasts?

Reasons to protect coastal areas:

• Valuable farmland, homes and infrastructure threatened by erosion.
• Tourism industry dependent on beaches and coastal scenery.
• Historical and cultural heritage sites at risk.
• Predicted sea level rise (SLR) linked to climate change threatens low-lying coastal areas.

Reasons NOT to intervene (or to allow managed retreat):

• Hard engineering is expensive and may only shift problems downstream.
• Natural beach processes are disrupted, removing the beach's own protective function.
• Maintaining a dynamic coast may be ecologically valuable.

Hard engineering strategies

Sea walls: vertical or curved concrete or rock walls built at the cliff base or along the shore. Very effective but very expensive (£2,000-£5,000 per metre). Reflected wave energy can accelerate erosion at the base.

Groynes: timber or rock structures built perpendicular to the coast to trap longshore drift and build up a beach. Effective locally but starve beaches downdrift of sediment.

Rock armour (rip-rap): large boulders placed at the cliff base. Cheaper than sea walls; absorbs wave energy; but looks unnatural and can be moved by extreme waves.

Offshore breakwaters: submerged or partially submerged barriers that break the force of waves before they reach the shore.

Soft engineering strategies

Beach nourishment (replenishment): adding sand or pebbles to a beach to make it wider and higher, increasing its capacity to absorb wave energy. Needs repeated reapplication (1-3 years). NI example: Portrush's West Strand has been nourished.

Managed retreat (realignment): allowing the sea to flood low-lying land (usually agricultural) deliberately, creating new intertidal habitats (salt marsh). Salt marsh is highly effective at absorbing wave energy. Cheaper than hard engineering.

Dune stabilisation: planting marram grass and other vegetation to stabilise sand dunes, which act as natural barriers to coastal flooding. Dunes also have high ecological value.

NI case study — Portrush / Causeway Coast

The north Antrim coast (including Portrush, Portstewart and the Causeway Coast) is managed by the Department for Infrastructure NI and the National Trust. Strategies used include:

• Rock armour and sea walls along Portrush seafront (protecting tourism infrastructure).
• Beach nourishment at West Strand, Portrush.
• Managed retreat in some agricultural sections.
• The National Trust's "Forever Coast" programme uses a mix of hard and soft engineering at the Giant's Causeway, prioritising the preservation of the World Heritage Site.