Coastal landscapes in the UK: processes, landforms and management

The UK coast is constantly reshaped by waves, weathering and human management. Examiners want a clear chain: wave type → process → landform → human response.

Wave types

• Constructive waves — long wavelength, low height; strong swash, weak backwash; carry sand up the beach to build it. Form in calm conditions. Beaches with constructive waves are gentle and wide.
• Destructive waves — short wavelength, high frequency; weak swash, strong backwash; pull sand off the beach. Form in storms; produce steeper beaches and erode landforms.

Coastal processes

Weathering (in situ)

• Mechanical — freeze-thaw shatters cliffs in winter; salt-crystal growth in tropics.
• Chemical — acidic rainwater dissolves limestone and chalk (carbonation).
• Biological — burrowing organisms, plant roots prising rock.

Mass movement

• Sliding — large blocks slide down a slope.
• Slumping — saturated cliffs (e.g. clay) rotate down (Holderness coast).
• Rockfall — blocks fall freely from cliffs.

Erosion

• Hydraulic action — water and trapped air forced into cracks.
• Abrasion — sediment picked up by waves grinds against the cliff.
• Attrition — sediment particles knock together and become rounder.
• Solution — chemical dissolution of soluble rocks.

Transportation

• Longshore drift — waves break at an angle, swash carries sediment up at an angle, backwash drags it straight back; net movement along the beach.
• Suspension (small particles in water column).
• Saltation (bouncing).
• Traction (rolling on bed).

Deposition

Wherever the sea loses energy — sheltered bays, behind groynes, in calm estuaries.

Landforms of erosion

The classic sequence on a discordant coast: Cracks → caves → arches → stacks → stumps

• Headlands and bays form where alternating hard and soft rock layers meet the sea.
• Cliffs form where waves erode rock faces; wave-cut notches at the base lead to cliff retreat, leaving a wave-cut platform.
• A vertical line of weakness in a cliff erodes into a cave, then through to form an arch (Durdle Door, Dorset).
• The arch eventually collapses, leaving a stack (Old Harry, Studland), which erodes to a stump.

Landforms of deposition

• Beaches — sand or shingle accumulating in the swash zone.
• Spits — sand/shingle extending out into the sea where the coast changes direction (Spurn Head, Yorkshire; Chesil Beach connecting to Portland is a tombolo).
• Bars — spits that grow across a bay, sealing off a lagoon.
• Tombolos — connect an offshore island to the mainland.
• Sand dunes — wind-blown sand trapped by marram grass; mobile foredunes mature into fixed back dunes.
• Salt marshes — silt deposited in sheltered estuaries; halophyte vegetation traps more silt; develops into mature marsh.

Coastal management

Two big choices: hard engineering (built defences) or soft engineering (working with nature). Increasingly, coasts use managed retreat to abandon undefendable areas.

Hard engineering

Strategy	What it is	Pros	Cons
Sea wall	Concrete wall at base of cliff	Reflects waves, protects buildings	Expensive (~£5 000/m); unsightly; can disrupt sediment supply
Groynes	Wooden/rock fingers across the beach	Trap sediment; build up beach	Starves downdrift coast → terminal groyne syndrome
Rock armour (rip-rap)	Large boulders piled at the base of cliffs	Cheap-ish; absorbs wave energy	Ugly; can shift in storms
Gabions	Steel-mesh cages of stone	Cheaper than walls	Short lifespan (5–10 years)

Soft engineering

Strategy	What it is	Pros	Cons
Beach nourishment	Adding sand to a beach	Natural look; maintains tourism	Needs repeating; expensive sand source
Dune regeneration	Planting marram grass; fencing	Cheap; ecological benefits	Slow; only works on dune coasts
Managed retreat	Letting low-value land flood	Saves money long-term; recreates saltmarsh	Politically difficult; affects landowners

Coastal management case study — Holderness coast

The Holderness coast (Yorkshire) is the fastest-eroding coastline in Europe — soft glacial till is retreating at ~1.7 m per year. Mappleton sea wall and groynes (1991) protected the village but accelerated erosion to the south, threatening Great Cowden farms (a clear example of terminal groyne syndrome).

Decisions are made through Shoreline Management Plans (SMPs) that classify each stretch as: hold the line / advance the line / managed realignment / no active intervention.

Examiner tips

For 9-mark coastal management questions, evaluate strategies on three axes: economic cost, environmental impact, and social acceptability. Always identify winners and losers — defending one stretch can damage another. Use named places.