What you'll learn
The coast is one of the most dynamic landscapes in the UK, constantly shaped by the sea through erosion, transport and deposition. For AQA GCSE Geography you need to understand coastal processes, the landforms created by erosion and deposition, and how coastlines are managed. This guide covers coastal processes, erosional landforms, depositional landforms, and coastal management strategies. By the end you should be able to explain how coastal landforms are created and evaluate ways of managing the coast.
Key terms and definitions
Erosion — The wearing away and removal of rock by the sea.
Weathering — The breakdown of rock in place, by physical, chemical or biological processes.
Longshore drift — The movement of material along a coast by waves approaching at an angle.
Deposition — The dropping of material carried by the sea when waves lose energy.
Headland — A hard-rock area of land jutting out into the sea.
Bay — A curved inlet of softer rock between headlands.
Hard engineering — Using artificial structures to control the sea.
Soft engineering — Working with natural processes to manage the coast.
Core concepts
Coastal processes
The coast is shaped by several processes:
- Weathering breaks down rock in place — for example, freeze-thaw (water freezing and expanding in cracks) and chemical weathering.
- Erosion by the sea happens in several ways: hydraulic power (the force of waves compressing air in cracks), abrasion (waves throwing rock fragments against the cliff), and attrition (rocks knocking together and becoming smaller and rounder).
- Transport — material is moved along the coast, mainly by longshore drift.
- Deposition — when waves lose energy, they drop the material they were carrying, building up new landforms.
Longshore drift
Longshore drift moves material along a coastline. Waves approach the beach at an angle (pushed by the prevailing wind), carrying material up the beach in the swash. The water then runs straight back down under gravity in the backwash. This zig-zag movement gradually transports sand and shingle along the coast. Longshore drift is important because it moves material that later builds depositional landforms such as spits.
Erosional landforms
Coastal erosion creates distinctive landforms:
- Headlands and bays form where a coastline has alternating hard and soft rock. The softer rock erodes faster, forming bays, while the harder rock is left jutting out as headlands.
- Cliffs and wave-cut platforms — waves erode the base of a cliff, forming a wave-cut notch; the cliff above eventually collapses and retreats, leaving a wave-cut platform at its base.
- Caves, arches, stacks and stumps — a sequence formed at a headland: waves erode a crack into a cave, the cave is eroded through the headland to form an arch, the arch collapses leaving an isolated stack, and the stack is eroded down to a stump.
Depositional landforms
Where the sea deposits material, it builds landforms:
- Beaches — formed from sand or shingle deposited by waves in a sheltered area, such as a bay.
- Spits — long, narrow ridges of material extending out from the coast, formed by longshore drift where the coastline changes direction; the end may curve (a recurved end), and a salt marsh often forms in the sheltered area behind.
- Bars — where a spit grows across a bay, joining two headlands and trapping a lagoon behind it.
Coastal management: hard engineering
Coasts are managed to protect people and property from erosion and flooding. Hard engineering uses artificial structures:
- Sea walls — reflect waves; effective but expensive.
- Groynes — wooden or rock barriers that trap material moved by longshore drift, building up the beach.
- Rock armour (rip-rap) — large boulders that absorb wave energy.
- Gabions — cages of rocks that absorb wave energy.
Hard engineering is effective but expensive, and can look unnatural or cause problems elsewhere along the coast.
Coastal management: soft engineering and managed retreat
Soft engineering works with natural processes:
- Beach nourishment — adding sand to a beach to build it up.
- Sand dune regeneration — restoring dunes that protect the coast.
Managed retreat allows low-value land to flood or erode in a controlled way, creating natural defences such as salt marshes. Soft engineering and managed retreat are often cheaper and more sustainable than hard engineering, but may be less effective for protecting high-value areas. Weighing these approaches is a common "evaluate" question.
Types of wave: constructive and destructive
Understanding the two types of wave helps explain why some coasts erode while others build up. Constructive waves are low, gentle waves with a strong swash (up the beach) and a weak backwash, so they deposit material and build up beaches. Destructive waves are high, powerful waves with a weak swash and a strong backwash, so they remove material and cause erosion. The type of wave depends on factors such as the wind strength and the fetch (the distance of open water the wind blows over). Whether a stretch of coast is dominated by constructive or destructive waves helps decide whether erosional or depositional landforms form there, which is a useful idea to bring into explanations.
Weathering and mass movement at the coast
As well as erosion by waves, cliffs are shaped by weathering and mass movement. Weathering weakens the rock in place — for example, freeze-thaw (water freezing and expanding in cracks) and chemical weathering by seawater. Once weakened, material can move downslope under gravity in mass movement, such as rockfalls (rock breaking away and falling) and landslides or slumping (large sections of saturated cliff sliding down). These processes work together with wave erosion to make cliffs retreat over time. Mentioning weathering and mass movement, not just wave erosion, gives a fuller explanation of how coastal cliffs change and why they can be unstable.
Worked examples
Example 1: How headlands and bays form
Explain how headlands and bays form. Where a coast has alternating bands of hard and soft rock, the softer rock is eroded more quickly, forming bays, while the more resistant hard rock is left projecting into the sea as headlands. So differences in rock resistance produce this pattern.
Example 2: The cave-arch-stack-stump sequence
Describe how a stack forms at a headland. Waves erode a crack in the headland into a cave. Continued erosion widens the cave through the headland to form an arch. The arch is undercut until it collapses, leaving an isolated pillar of rock called a stack, which is later eroded down to a stump.
Example 3: Longshore drift and a spit
Explain how longshore drift forms a spit. Longshore drift moves material along the coast. Where the coastline changes direction, material is deposited in the sheltered water, building a long, narrow ridge (a spit) extending out from the coast. The end may curve, and a salt marsh forms in the sheltered area behind.
Example 4: Evaluating a groyne
Give one advantage and one disadvantage of using groynes. An advantage is that groynes trap material moved by longshore drift, building up the beach, which protects the coast and helps tourism. A disadvantage is that by trapping material, they starve the coast further along of sediment, increasing erosion there.
Common mistakes and how to avoid them
A common error is confusing the erosion processes. Hydraulic power is the force of the water; abrasion is rocks thrown at the cliff; attrition is rocks wearing each other down. Learn each one.
Students often get the cave-arch-stack-stump sequence out of order. It is always cave → arch → stack → stump. Learn the order and the process at each stage.
Another mistake is describing longshore drift without the angle. Waves approach at an angle (swash), and the backwash returns straight down — this produces the zig-zag movement. The angled approach is essential.
When explaining headlands and bays, remember it depends on hard and soft rock: soft rock erodes to form bays, hard rock is left as headlands. Do not leave out the rock type.
Finally, for management questions, give a balanced answer. Hard engineering is effective but costly and can cause problems elsewhere; soft engineering is cheaper and more natural but may be less effective. Evaluate both.
Exam technique for "Physical Landscapes in the UK: Coastal Landscapes"
Learn the coastal processes (weathering, hydraulic power, abrasion, attrition, longshore drift) and use them to explain how each landform forms, in a clear step-by-step sequence.
Be able to identify and explain erosional landforms (headlands and bays, cliffs and wave-cut platforms, caves-arches-stacks-stumps) and depositional landforms (beaches, spits, bars), and to recognise them on OS maps.
For coastal management, compare hard and soft engineering and managed retreat, giving advantages and disadvantages and a reasoned judgement. Use precise terms — hydraulic power, abrasion, longshore drift, spit, groyne — throughout, and support map answers with grid references.
Quick revision summary
- Coastal processes: weathering, erosion (hydraulic power, abrasion, attrition), transport by longshore drift, and deposition.
- Longshore drift moves material along the coast in a zig-zag: waves approach at an angle (swash), backwash returns straight down.
- Erosional landforms: headlands and bays (hard/soft rock), cliffs and wave-cut platforms, and the cave → arch → stack → stump sequence.
- Depositional landforms: beaches, spits (with recurved ends and salt marshes), and bars.
- Hard engineering (sea walls, groynes, rock armour, gabions) is effective but costly; soft engineering (beach nourishment, dune regeneration) and managed retreat are cheaper and more natural.
- Evaluate management by weighing effectiveness, cost and effects elsewhere along the coast.