Coastal Landscapes and Change

What you'll learn

This guide covers all testable content on coastal landscapes and processes for WJEC GCSE Geography. You'll master the physical processes that shape coastlines, understand how distinctive landforms develop, and evaluate coastal management strategies. The content includes specific case studies required for your exam, focusing on UK examples and management approaches.

Key terms and definitions

Hydraulic action — erosion caused when waves compress air into cracks in rocks, forcing them apart through repeated pressure

Longshore drift — the zigzag movement of sediment along a beach caused by waves approaching at an angle and retreating perpendicular to the shore

Sub-aerial processes — weathering and mass movement processes that operate on the cliff face above the high tide line

Hard engineering — artificial structures built to protect coastlines from erosion and flooding, such as sea walls and groynes

Soft engineering — sustainable coastal management that works with natural processes, including beach nourishment and dune regeneration

Fetch — the distance of open water over which wind blows to generate waves; longer fetch produces larger, more powerful waves

Constructive waves — low-frequency waves with strong swash and weak backwash that build up beaches through deposition

Destructive waves — high-frequency waves with weak swash and strong backwash that erode beaches and transport sediment offshore

Core concepts

Coastal processes

Erosion processes

Four main processes erode coastlines:

• Hydraulic action: Wave impact forces air into cracks under pressure (up to 30 tonnes per square metre). When pressure releases, the crack widens. Most effective on jointed or fractured rock
• Abrasion/corrasion: Sediment carried by waves acts like sandpaper, wearing away rock surfaces. Beach pebbles and sand are the "tools" of erosion
• Attrition: Rocks and pebbles collide with each other, becoming smaller and more rounded. Creates progressively finer sediment moving along the coast
• Solution/corrosion: Chemical weathering dissolves minerals in rock, particularly effective on limestone and chalk coastlines

Wave power depends on fetch, wind speed, and wind duration. Atlantic-facing coasts experience higher energy conditions than sheltered coasts like the Bristol Channel.

Weathering and mass movement

Sub-aerial processes attack cliffs above the wave zone:

Physical weathering:

• Freeze-thaw weathering: Water enters cracks, freezes (expanding by 9%), and forces rock apart
• Salt crystallisation: Salt water evaporates leaving crystals that grow and exert pressure in rock pores

Chemical weathering:

• Carbonation: Rainwater (slightly acidic) reacts with limestone and chalk, dissolving calcium carbonate

Biological weathering:

• Plant roots grow into cracks, widening them
• Burrowing animals create weaknesses

Mass movement transfers weathered material downslope:

• Rockfall: Fragments break away from cliff face
• Landslides: Blocks of rock slide downslope along a slip plane, often after heavy rainfall saturates clay layers
• Slumping: Rotational movement of material along a curved slip plane, creating stepped terraces

Transportation and deposition

Waves transport sediment through four processes:

• Traction: Large stones roll along the seabed
• Saltation: Smaller stones bounce along the seabed
• Suspension: Fine particles (silt, clay) carried within the water column
• Solution: Dissolved minerals transported invisibly

Longshore drift moves material along coastlines. Waves approach at an angle (determined by prevailing wind direction), carrying sediment up the beach at this angle. Gravity pulls backwash straight down the beach. This zigzag pattern transports millions of tonnes of sediment annually along UK coasts.

Deposition occurs when waves lose energy:

• In sheltered bays protected from dominant wind direction
• Where coastline changes direction (headlands create sheltered zones)
• When constructive waves dominate (spring/summer conditions)
• Where obstacles (groynes, piers) interrupt longshore drift

Erosional landforms

Headlands and bays

Form on coastlines with alternating resistant and less resistant rock:

• Weaker rock (clay, sand) erodes faster, creating bays
• Resistant rock (limestone, chalk, granite) erodes slower, forming headlands
• Wave refraction concentrates erosion on headland sides
• Example: Swanage Bay (Dorset) — chalk headlands with clay bay between

Cliffs and wave-cut platforms

Develop through marine erosion at cliff base:

1. Waves attack cliff base through hydraulic action and abrasion
2. Wave-cut notch forms at high tide line
3. Overhanging rock becomes unstable
4. Cliff collapses through mass movement
5. Process repeats; cliff retreats inland
6. Wave-cut platform — gently sloping rocky surface exposed at low tide (angle typically 1-4°)

Cliff profiles vary with rock type:

• Resistant rock: near-vertical cliffs (Old Harry, Dorset — chalk)
• Weak rock: gently sloping profiles (Holderness, Yorkshire — boulder clay)

Caves, arches, stacks and stumps

Sequential development on headlands:

1. Waves attack weaknesses (faults, joints) in headland sides through hydraulic action
2. Cave forms as weakness enlarges
3. Caves on opposite sides of headland meet, forming an arch
4. Continued erosion widens arch; roof becomes unstable
5. Arch roof collapses, leaving isolated stack
6. Stack base eroded, topples to form stump (visible only at low tide)

Classic UK example: Old Harry Rocks (Dorset) — stack with adjacent stump showing full sequence.

Depositional landforms

Beaches

Accumulations of sediment (sand, shingle, pebbles) between high and low tide marks:

• Berms: ridges of coarser material deposited by high spring tides
• Cusps: semicircular depressions on beach face
• Sandy beaches: gentle gradients (formed by constructive waves)
• Shingle beaches: steep gradients (formed by powerful swash)

Sediment size decreases with distance from source (attrition). Chesil Beach (Dorset) demonstrates this: pebbles decrease from 7cm (northwest) to 2cm (southeast) over 28km.

Spits

Elongated ridges of sand/shingle projecting from coastline:

Formation process:

1. Longshore drift transports sediment along coast
2. Coastline changes direction (e.g., river estuary)
3. Sediment continues in original direction, depositing in open water
4. Spit grows across bay or estuary mouth
5. Recurved end forms where waves bend around spit tip (secondary wind direction)
6. Salt marsh develops in sheltered water behind spit

Example: Spurn Head (Yorkshire) — 5.5km spit at Humber estuary mouth. Shows classic recurved end and requires ongoing management as it erodes 2m annually.

Bars and tombolo

Bar: forms when spit extends completely across a bay, enclosing a lagoon. Example: Slapton Ley (Devon) — freshwater lagoon behind shingle bar.

Tombolo: sand/shingle bar connecting island to mainland. Forms when island causes wave refraction, creating low-energy zone where deposition occurs behind island.

Coastal management strategies

Coastal areas face risks from erosion (losing land) and flooding (seawater inundation). Management approaches balance protection costs against economic value of protected areas.

Hard engineering

Artificial structures that directly interfere with natural processes:

Sea walls

• Curved concrete/stone barriers at cliff base
• Reflect wave energy back to sea
• Advantages: effective erosion protection; promenade on top
• Disadvantages: expensive (£5,000-10,000 per metre); cause beach scouring; require maintenance
• Example: Aberystwyth (Wales) — £14 million sea wall rebuilt 2015

Groynes

• Wooden/rock barriers built perpendicular to coast
• Trap sediment moved by longshore drift
• Advantages: build up beach (natural defence); relatively cheap (£5,000 per groyne)
• Disadvantages: starve beaches downdrift of sediment; unattractive
• Example: Hornsea (Yorkshire) — 8 groynes protect town

Rip-rap/rock armour

• Large boulders (5-10 tonnes) placed at cliff base
• Absorb wave energy
• Advantages: effective; gaps allow sediment movement
• Disadvantages: expensive (£1,000-3,000 per metre); visually intrusive; imported stone
• Example: Pevensey Bay (Sussex)

Gabions

• Wire cages filled with stones
• Absorb wave energy; allow drainage
• Advantages: cheap (£100 per metre); flexible
• Disadvantages: short lifespan (10-25 years); wire rusts; unattractive

Soft engineering

Works with natural processes; more sustainable long-term:

Beach nourishment

• Adding sand/shingle to beach from elsewhere
• Widens beach (natural wave energy absorber)
• Advantages: natural appearance; increases tourism
• Disadvantages: expensive (£3,000 per metre); requires replenishment every 5-10 years; dredging impacts marine ecosystems
• Example: Pevensey Bay — 3 million m³ added since 1996

Dune regeneration

• Stabilising/rebuilding sand dunes with vegetation (marram grass)
• Fencing protects new growth from trampling
• Advantages: cheap (£200-2,000 per 100m); provides habitat; natural appearance
• Disadvantages: time-consuming; vulnerable to storms initially; restricts access
• Example: Formby (Lancashire) — EU-funded project

Managed retreat

• Allowing low-value land to flood naturally
• Removes artificial defences; creates salt marsh
• Advantages: cheap long-term; creates wildlife habitat; sustainable
• Disadvantages: compensation costs for landowners; loss of farmland; politically controversial
• Example: Medmerry (Sussex) — 7km of defences removed 2013, creating 183 hectares of salt marsh

Coastal management case study: Holderness Coast

Required WJEC case study demonstrating management challenges:

Location and context:

• 61km stretch between Flamborough Head and Spurn Head (Yorkshire)
• Fastest eroding coastline in Europe: 1.8m per year average
• Boulder clay cliffs (soft, easily eroded)
• 30 villages lost to sea since Roman times

Management strategies:

• Mappleton (protected): rip-rap and two rock groynes installed 1991 (£2 million) protect 50 properties and B1242 coast road
• Great Cowden (unprotected): lost 25 houses since Mappleton defences built; beaches starved of sediment by Mappleton groynes
• Spurn Head: groynes maintain access road to lifeboat station and gas terminal

Conflicts:

• Protected areas starve downdrift locations of sediment
• Cost-benefit analysis: protecting high-value settlements leaves low-value areas exposed
• Farmers lose land but protection is uneconomical

Future management:

• Strategic retreat from low-value areas
• Focus protection on key infrastructure (gas terminals, major roads)
• Sediment management planning along entire coastline

Worked examples

Example 1: 4-mark question

Question: Explain how a wave-cut platform is formed. [4 marks]

Mark scheme answer: Waves attack the base of the cliff through processes such as hydraulic action and abrasion [1]. This creates a wave-cut notch at the high tide line [1]. The overhanging rock above becomes unstable and eventually collapses [1]. As this process repeats, the cliff retreats inland leaving a gently sloping rocky platform exposed at low tide [1].

Examiner note: Each developmental stage needs clear identification. Use correct terminology (wave-cut notch, platform). Link processes to landform development.

Example 2: 6-mark question

Question: Compare the costs and benefits of using hard engineering to protect coastlines. [6 marks]

Mark scheme answer: Hard engineering methods such as sea walls provide effective protection against erosion and flooding [1], directly protecting property and infrastructure worth millions of pounds [1]. They provide immediate protection once constructed and can last 30-50 years [1]. However, these structures are extremely expensive to build, with sea walls costing £5,000-10,000 per metre [1]. They require ongoing maintenance which adds to costs [1]. Hard engineering can negatively impact other areas, for example groynes trap sediment so beaches downdrift are starved of material and erosion increases there [1]. Structures can also look unattractive and impact tourism [1].

Examiner note: "Compare" requires both advantages and disadvantages. Use specific examples and figures. Link consequences clearly (e.g., groynes causing downdrift effects).

Example 3: 9-mark case study question

Question: Using a named coastal area, evaluate the success of coastal management strategies. [9 marks + 3 SPaG]

Indicative content:

• Named location: Holderness Coast, Yorkshire
• Management strategies: hard engineering (Mappleton groynes/rip-rap) vs unprotected areas (Great Cowden)
• Successes: Mappleton defences protect 50 properties and B1242 road; erosion reduced from 1.8m to 0.3m annually since 1991
• Limitations: Great Cowden experiences accelerated erosion (starved of sediment by Mappleton groynes); 25 houses lost
• Economic factors: cost-benefit analysis means only high-value areas protected; compensation issues for unprotected landowners
• Environmental impacts: loss of natural processes; sediment starvation
• Evaluation: successful at local scale but creates problems elsewhere; unsustainable long-term; strategic managed retreat needed for low-value areas

Examiner note: Case study questions require specific place detail (names, locations, figures). Evaluate means weighing up successes against limitations. Make a judgement. Write in continuous prose. SPaG marks available.

Common mistakes and how to avoid them

• Confusing weathering and erosion: Weathering breaks down rock in situ; erosion involves movement. Sub-aerial processes are weathering; marine processes are erosion. Be precise about which you're describing

• Vague process descriptions: Don't write "the waves hit the cliff." Instead specify: "hydraulic action occurs when waves compress air into cracks under high pressure." Use proper terminology throughout

• Forgetting longshore drift mechanics: Always explain that waves approach at an angle (due to prevailing wind) but backwash returns perpendicular (due to gravity). Draw diagrams in exams to clarify your explanation

• Muddling destructive and constructive waves: Destructive waves have strong backwash (erosion); constructive waves have strong swash (deposition). Link these to landforms: destructive waves create steep beaches and erode cliffs; constructive waves create wide, gently-sloping sandy beaches

• Case study without specifics: Generic answers score poorly. Your Holderness Coast answer needs: place names (Mappleton, Great Cowden), figures (1.8m erosion annually, £2 million cost), dates (1991 defences built), specific strategies (rock groynes, rip-rap)

• No evaluation in evaluate questions: Listing points isn't enough. Make judgements: "While Mappleton's defences successfully protect the village, the strategy is unsustainable because it accelerates erosion elsewhere and requires ongoing public funding"

Exam technique for "Coastal Landscapes and Change"

• Command words matter: "Describe" = what you can see/what happens (no explanation needed). "Explain" = reasons why/how processes work. "Evaluate" = weigh up strengths/weaknesses and make judgements. "Assess" = consider different viewpoints/factors. Marks are lost by describing when explaining is required

• Mark allocation guides answer length: 1 mark = 1 developed point. A 4-mark question needs four distinct points or two points developed with detail/examples. Don't write paragraphs for 2-mark questions; don't write one sentence for 6-mark questions

• Case study questions are worth learning thoroughly: Named examples can appear in questions from 4 to 12 marks. Holderness Coast should include: location details, rock types, erosion rates, specific management strategies with costs, protected vs unprotected areas, conflicts, and evaluation of success. Practice writing this under timed conditions

• Use diagrams strategically: Annotated diagrams can explain formation sequences (cave-arch-stack-stump) or processes (longshore drift) more clearly than text alone. Add labels with arrows. In 6+ mark questions, a diagram plus written explanation often scores higher than text alone

Quick revision summary

Coastal landscapes form through interacting processes: erosion (hydraulic action, abrasion, attrition, solution), weathering and mass movement (sub-aerial processes), transportation (longshore drift), and deposition. Erosional landforms include cliffs, wave-cut platforms, caves, arches, stacks and stumps on headlands. Depositional landforms include beaches, spits and bars. Management strategies divide into hard engineering (sea walls, groynes, rip-rap) and soft engineering (beach nourishment, dune regeneration, managed retreat). The Holderness Coast demonstrates management challenges where protecting high-value areas accelerates erosion elsewhere, creating conflicts requiring sustainable long-term planning.