What you'll learn
Coastal landscapes are shaped by the constant interaction of the sea, the weather and the rocks. This guide covers what you need for Edexcel GCSE Geography on coastal landscapes and change: how geology (rock type and structure) influences the shape of the coast, weathering and mass movement processes, the marine processes of erosion, transportation and deposition, the formation of erosional landforms (headlands and bays, caves, arches, stacks and stumps, wave-cut platforms) and depositional landforms (beaches, spits and bars), the role of waves and weather, how human activity affects the coast, the risks from coastal erosion and flooding, and the strategies used to manage them: hard engineering, soft engineering and integrated coastal management. It uses the Holderness coast in Yorkshire as an example of a rapidly eroding coastline.
Exam questions range from short definitions to extended explanations of how a landform forms, and evaluations of management strategies. For landform questions, examiners look for a clear sequence of processes; for evaluations, a balanced judgement supported by evidence.
Key terms and definitions
Concordant coast — Rock types run parallel to the coastline, forming a smooth coast with coves.
Discordant coast — Bands of different rock run at right angles to the coastline, forming headlands and bays.
Hydraulic action — The force of waves compressing air in cracks, widening them.
Abrasion — Rocks carried by waves scraping and wearing away the cliff and seabed.
Attrition — Rocks carried by waves knocking together, becoming smaller and rounder.
Solution — Chemical erosion where seawater dissolves certain rocks, such as chalk and limestone.
Longshore drift — The movement of sediment along the coast by waves approaching at an angle.
Destructive wave — A tall, frequent wave with a strong backwash that erodes the coast.
Constructive wave — A low, less frequent wave with a strong swash that deposits material.
Mass movement — The downslope movement of material under gravity, such as slumping and rockfalls.
Hard engineering — Building artificial structures, such as sea walls and groynes, to control natural processes.
Soft engineering — Working with natural processes, for example beach nourishment and managed retreat.
Integrated coastal zone management (ICZM) — Managing a whole stretch of coast in a coordinated, sustainable way.
Core concepts
Geology and coastal shape
Rocks differ in resistance. Hard rocks such as granite and chalk erode slowly; soft rocks such as clay and sands erode quickly. Where bands of hard and soft rock meet the coast at right angles — a discordant coast — the soft rock erodes back to form bays, leaving the hard rock sticking out as headlands. Where rocks run parallel to the coast — a concordant coast — a resistant outer band protects softer rock behind it; if the sea breaks through, it can erode a rounded cove, such as Lulworth Cove in Dorset.
Rock structure matters too. Joints, faults and bedding planes are lines of weakness that waves exploit. Cliffs made of rocks that dip seaward are more prone to slides.
Weathering and mass movement
Weathering breaks down rock in place:
- mechanical (freeze-thaw) — water in cracks freezes, expands and widens them;
- chemical — rainwater, which is slightly acidic, dissolves limestone and chalk;
- biological — plant roots widen cracks and burrowing animals loosen material.
Mass movement moves weathered material downhill:
- rockfall — fragments fall from steep cliffs;
- sliding — material moves along a slip plane;
- slumping — saturated soft rock such as clay slips along a curved surface, leaving a rotational scar.
Heavy rain saturates cliffs, adding weight and lubricating slip planes, so mass movement often follows storms.
Waves and weather
Waves are created by wind blowing across the sea. Their energy depends on wind speed, wind duration and the fetch (the distance of open water the wind blows over). In the UK, the prevailing south-westerly winds blow across the Atlantic, giving long fetches and powerful waves on south-west coasts.
Destructive waves are tall and frequent (around 10–14 per minute), with a strong backwash that drags material away — they dominate in storms and winter. Constructive waves are low and less frequent (around 6–8 per minute), with a strong swash that pushes material up the beach — they build beaches.
Weather and climate affect the coast through storms (powerful waves and surges), seasonal changes in wave type, rainfall (saturating cliffs) and temperature (freeze-thaw).
Marine erosion, transportation and deposition
Erosion: hydraulic action, abrasion, attrition and solution.
Transportation: waves and currents move material by traction (rolling large boulders), saltation (bouncing pebbles), suspension (fine particles carried in the water) and solution (dissolved minerals). Longshore drift moves sediment along the coast: waves approach at an angle driven by the prevailing wind, the swash carries material diagonally up the beach, and the backwash pulls it straight back down under gravity, so material zigzags along the shore.
Deposition happens when waves lose energy — in sheltered bays, where the coast changes direction, or where constructive waves dominate.
Erosional landforms
Headlands and bays form on discordant coasts as described above. Once formed, headlands receive more wave energy because waves refract (bend) around them, while bays become sheltered and collect beaches.
Caves, arches, stacks and stumps form on headlands:
- Hydraulic action and abrasion attack a line of weakness, such as a joint, enlarging it into a cave.
- Erosion continues through the headland from both sides to form an arch (such as Durdle Door in Dorset).
- The arch roof is weakened by erosion beneath and weathering above, and eventually collapses, leaving an isolated column — a stack (such as Old Harry in Dorset).
- The stack is eroded at its base until it collapses into a stump, covered at high tide.
Wave-cut platforms form as waves erode the base of a cliff between high and low tide, forming a wave-cut notch. The cliff above becomes unsupported and collapses. Repeated, the cliff retreats inland, leaving a gently sloping rocky platform exposed at low tide.
Depositional landforms
Beaches form where deposition exceeds erosion. Sand beaches are gently sloping; shingle beaches are steeper. Berms are ridges marking high-tide lines.
Spits are long, narrow ridges of sand or shingle extending from the land into the sea:
- Longshore drift carries material along the coast.
- Where the coast changes direction (for example at a river mouth), material continues to be deposited in the original direction.
- The spit grows out into the sea.
- Changes in wind direction can curve the end into a recurved tip.
- Sheltered water behind the spit becomes calm, so silt is deposited, forming salt marsh.
Spurn Head, at the end of the Holderness coast, is a well-known example.
Bars form where a spit grows across a bay, joining two headlands and trapping a lagoon behind it.
Human activity and the coast
Human actions can speed up or slow down coastal change. Building on cliff tops adds weight and drainage water; removing sediment, for example by dredging, can starve beaches; building groynes in one place can increase erosion further along the coast by cutting off the supply of sediment carried by longshore drift. Agriculture, industry, ports and tourism all place pressure on coastlines.
Holderness: a rapidly eroding coast
The Holderness coast in East Yorkshire is one of the fastest-eroding coastlines in Europe. Its cliffs are made of soft boulder clay (till) deposited by glaciers, which is easily eroded and prone to slumping. Powerful destructive waves from the North Sea, with a long fetch, attack the cliff base, and longshore drift carries material south towards Spurn Head. Villages have been lost to the sea over centuries, roads have fallen over cliff edges, and farmland and caravan parks are threatened.
Management includes sea walls, rock armour and groynes at places such as Hornsea, Withernsea and Mappleton. Protecting Mappleton with rock armour and groynes saved the village and its road, but trapping sediment there reduced the supply of beach material further south, increasing erosion downdrift — a classic example of how protecting one place can create problems elsewhere.
Risks from coastal retreat and flooding
Coastal erosion threatens homes, businesses, roads and farmland, lowering property values and making homes impossible to insure. Coastal flooding is made more likely by storm surges (low pressure and strong winds raising sea levels) and by rising sea levels caused by climate change, as warmer water expands and ice melts. Low-lying coasts, such as parts of eastern England, are particularly at risk.
Managing the coast
Hard engineering
| Method | How it works | Advantages | Disadvantages |
|---|---|---|---|
| Sea wall | Concrete wall reflects waves | Effective; protects promenades | Very expensive; can be undermined; reflects energy |
| Groynes | Timber or rock barriers trap longshore drift | Build up beaches | Starve beaches downdrift |
| Rock armour | Large boulders absorb wave energy | Relatively cheap; long-lasting | Unattractive; can be moved by storms |
Soft engineering
| Method | How it works | Advantages | Disadvantages |
|---|---|---|---|
| Beach nourishment | Adding sand or shingle to beaches | Natural look; supports tourism | Must be repeated; costly over time |
| Dune regeneration | Planting marram grass, fencing | Cheap; creates habitats | Needs time; can be damaged by people |
| Managed retreat | Letting areas flood or erode | Cheap; creates salt marsh habitats | Loss of land; compensation disputes |
Integrated coastal zone management plans for a whole stretch of coast (often a sediment cell) so that decisions in one place do not cause problems elsewhere. Shoreline management plans set one of four policies for each section: hold the line, advance the line, managed realignment, or no active intervention. Decisions balance cost, the value of what is protected, environmental impacts and the views of different stakeholders.
Worked examples
Example 1: Explaining a landform
Explain the formation of a stack. (4 marks)
Answer: Waves erode a line of weakness in a headland by hydraulic action and abrasion, forming a cave (1). The cave is eroded through the headland to form an arch (1). The arch roof is weakened by erosion beneath and weathering above, until it collapses (1). This leaves an isolated pillar of rock separated from the headland — a stack (1).
Example 2: Longshore drift
Describe how longshore drift moves sediment. (3 marks)
Answer: Waves approach the beach at an angle due to the prevailing wind (1). The swash carries sediment diagonally up the beach (1). The backwash carries it straight back down under gravity, so sediment moves along the coast in a zigzag (1).
Example 3: Evaluating management
Assess the use of groynes to protect a coastline.
Answer: Groynes trap sediment carried by longshore drift, building a wider beach that absorbs wave energy and protects the cliffs behind, and wider beaches benefit tourism. However, they reduce the sediment reaching beaches further along the coast, which can increase erosion downdrift, as happened south of Mappleton. Overall, groynes are effective locally but should be used as part of an integrated plan.
Common mistakes and how to avoid them
- Confusing weathering and erosion. Weathering breaks rock down in place; erosion wears it away by moving material.
- Describing landforms without processes. Name hydraulic action and abrasion.
- Getting the order wrong. Crack → cave → arch → stack → stump.
- One-sided evaluations of management. Give advantages, disadvantages and a judgement.
- Forgetting the knock-on effects of hard engineering downdrift.
Exam technique for "Coastal Landscapes and Change"
- For "explain the formation" questions, write the processes in sequence, using connectives such as "this leads to…".
- Annotated sketches can help in extended answers, but explain them in words too.
- Use named examples (Holderness, Mappleton, Spurn Head, Dorset landforms) to add place detail.
- In evaluation questions, consider cost, effectiveness, environmental impact and effects elsewhere.
Quick revision summary
- Geology: hard and soft rocks; discordant coasts form headlands and bays; concordant coasts form coves.
- Weathering (freeze-thaw, chemical, biological) and mass movement (rockfall, sliding, slumping).
- Waves: destructive (erode) and constructive (deposit); fetch, wind speed and duration control energy.
- Erosion: hydraulic action, abrasion, attrition, solution. Transport: traction, saltation, suspension, solution; longshore drift.
- Landforms: headlands, bays, caves, arches, stacks, stumps, wave-cut platforms; beaches, spits, bars.
- Holderness: soft boulder clay, rapid erosion, management at Mappleton with downdrift effects.
- Management: hard (sea walls, groynes, rock armour), soft (nourishment, dunes, managed retreat), ICZM and shoreline management plans.