Edexcel GCSE Geography: Coastal Environments

Key Takeaways: Coastal Environments

1. Coastal Systems & Processes

• Coast as an Open System:
  • Inputs: Sediment from rivers, erosion.
  • Outputs: Sediment lost to open sea.
  • Example: River deltas supply sediment.
• Wave Types:Constructive WavesDestructive WavesLong wavelength, gentle slopeShort wavelength, steep slopeStrong swash, weak backwashWeak swash, strong backwashBuild beaches (deposition)Erode beaches (removal)
• Erosion Processes (HACA):
  1. Hydraulic Action: Force of waves compressing air in cracks.
  2. Abrasion: Rocks hurled at cliffs.
  3. Corrosion: Dissolving rocks (e.g., limestone).
  4. Attrition: Rocks collide and break into smaller pieces.
  • Tip: Use the mnemonic HACA to remember these.

2. Erosional Landforms

• Headlands & Bays: Formed due to alternating resistant (e.g., limestone) and less resistant rocks (e.g., clay).
  • Discordant Coastline: Rocks at right angles to the sea (e.g., Swanage Bay, UK).
• Cliffs & Wave-Cut Platforms:
  • Cliffs retreat due to undercutting by waves, leaving a platform.
• Caves → Arches → Stacks → Stumps:
  • Case Study: Durdle Door, Dorset (arch).

3. Depositional Landforms

• Beaches: Shaped by constructive waves.
  • Sandy beaches: Gentle waves. Shingle beaches: High-energy waves.
• Spits: Longshore drift deposits sediment where the coast changes direction (e.g., Spurn Head, Yorkshire).
  • Formation Tip: Draw a spit with a recurved end due to wind changes.
• Bars & Lagoons: Spits that join two headlands (e.g., Slapton Ley, Devon).

4. Factors Affecting Coasts

• Geology: Soft rocks (clay) erode faster than hard rocks (granite).
• Vegetation: Stabilises sand dunes (e.g., marram grass).
• Sea-Level Changes:
  • Submergent: Rias (drowned valleys, e.g., Kingsbridge Estuary).
  • Emergent: Raised beaches (e.g., Isle of Arran, Scotland).
• Human Activities:
  • Case Study: Miami, Florida – threatened by sea-level rise.

5. Coastal Ecosystems

• Coral Reefs:
  • Conditions: Warm water (>18∘C18∘C), shallow (<25m), clear.
  • Threats: Bleaching (warming), pollution (e.g., Great Barrier Reef).
• Mangroves:
  • Adaptations: Prop roots, salt filtration.
  • Value: Protect coasts (e.g., reduced 2004 tsunami impact in areas with mangroves).
• Salt Marshes & Sand Dunes:
  • Zonation: Plants like cordgrass (salt marsh) and marram grass (dunes) colonise.

6. Coastal Management

• Hard Engineering:MethodExampleDisadvantageSea WallBrightonExpensive, uglyGroynesMappleton, HoldernessDownstream erosion
• Soft Engineering:
  • Beach Replenishment: Repeatedly needed (e.g., Bournemouth).
  • Managed Retreat: Allow flooding to create salt marshes (e.g., Abbots Hall Farm, Essex).
• Conflict Matrix: Use to analyse stakeholders (e.g., tourism vs conservation).

7. Case Studies

• Holderness Coast, UK:
  • Erosion Rate: 1–2m/year due to soft boulder clay and destructive waves.
  • Management: £2m rock groynes at Mappleton (protects village but worsens erosion elsewhere).
• Coral Reef Protection: St Lucia, Caribbean – zoning restricts fishing/tourism.

8. Exam Tips

• Diagrams: Practise annotated sketches for:
  • Longshore drift (show swash/backwash at angle).
  • Formation of a stack (label hydraulic action, cave → arch → collapse).
• Maths Skills: Use quadrats in transects to measure pebble size (e.g., record size every 5m up a beach).
• 6-Mark Questions: Structure answers using PEEL (Point, Example, Explain, Link).

Key Rules:

• Swash vs Backwash: Swash is the wave moving up the beach; backwash is the water returning down.
• Longshore Drift Direction: Determined by prevailing wind (e.g., UK south-west winds cause drift eastwards).

50 Unique GCSE Geography Questions on Coastal Environments

Section A: Short Answer Questions (1-2 marks each)

1. Define an open system in the context of coastal environments.
2. State two differences between constructive and destructive waves.
3. Name the four erosion processes caused by destructive waves.
4. What is longshore drift?
5. Identify two factors that influence the formation of headlands and bays.
6. How does vegetation stabilise sand dunes?
7. What is a ria and how does it form?
8. Explain why coral reefs require clear, clean water.
9. Name two threats to mangrove ecosystems.
10. What is the primary function of a sea wall?
11. Define managed retreat.
12. Give two advantages of soft engineering over hard engineering.
13. What is a spit and how does it form?
14. Why are fjords associated with submergent coastlines?
15. State two human activities that contribute to coastal erosion.

Section B: Medium Answer Questions (3-4 marks each)

16. Explain how a wave-cut platform is formed.
17. Describe the role of swash and backwash in beach formation.
18. Compare concordant and discordant coastlines.
19. Outline the process of cliff formation and retreat.
20. How does geology influence the shape of coastal cliffs?
21. Explain the global distribution of coral reefs using the factors listed in Figure 2.10.
22. Describe how mangrove roots adapt to their environment.
23. Analyse why salt marshes are valuable for coastal defence.
24. Discuss the conflicts between tourism and conservation in coastal areas.
25. Explain how groynes can cause increased erosion downstream.
26. Why might a do nothing approach to coastal management be controversial?
27. Describe the formation of a bar.
28. How does beach replenishment work, and what are its limitations?
29. Explain the term corrosion in coastal erosion.
30. Compare the characteristics of sandy and shingle beaches.

Section C: Case Study and Diagram-Based Questions (4-6 marks each)

31. Using the Holderness Coast as an example, explain why some coastlines retreat rapidly.
32. Draw and label a diagram showing the formation of a stack.
33. Describe the threats to coral reefs, using the Caribbean as a case study.
34. Annotate a diagram to show how longshore drift operates.
35. Explain how Bangladesh’s Coastal Zone Policy uses mangroves for land reclamation.
36. Discuss the impacts of rising sea levels on Miami, Florida.
37. Draw a conflict matrix for two coastal stakeholders and justify your choices.
38. Describe the formation of sand dunes, including plant succession.
39. Analyse the advantages and disadvantages of rip-rap as a coastal defence.
40. Using Figure 2.16, explain why Mappleton’s coastal defences may have worsened erosion elsewhere.

Section D: Extended Response Questions (6-9 marks each)

41. Evaluate the effectiveness of hard engineering strategies in coastal management.
42. Assess the ecological and economic value of coral reefs.
43. Discuss the causes and consequences of coastal erosion on human settlements.
44. Compare the formation of erosional and depositional coastal landforms.
45. Explain how sub-aerial processes and marine processes interact to shape coastlines.
46. Evaluate the role of human activity in both harming and protecting coastal ecosystems.
47. Analyse the factors that make coastal areas prone to conflicts between stakeholders.
48. Discuss the global significance of mangroves in mitigating climate change impacts.
49. Using named examples, assess the success of coastal management strategies.
50. Explain how a quadrat could be used to collect pebble measurements in a beach transect.

Detailed Answers

1. Open system: A coastal system where energy and matter (e.g., sediment) are exchanged with surrounding environments. Inputs (e.g., river sediment) and outputs (e.g., sediment lost to the sea) occur.
2. Constructive vs destructive waves:
   • Constructive: Long wavelength, strong swash, builds beaches.
   • Destructive: Short wavelength, strong backwash, erodes beaches.
3. Erosion processes: Hydraulic action, abrasion, corrosion, attrition.
4. Longshore drift: Movement of sediment along the coast by waves approaching at an angle. Swash carries sediment up the beach; backwash returns it perpendicularly.
5. Headlands and bays: Form due to differential erosion of resistant (e.g., limestone) and less resistant rocks (e.g., clay).
6. Vegetation stabilisation: Roots bind sand, reducing wind erosion; plants trap sediment, allowing dunes to grow.
7. Ria: Drowned river valley formed by rising sea levels (submergent coastline).
8. Coral reef water clarity: Sediment blocks sunlight needed for coral symbiosis with algae.
9. Mangrove threats: Aquaculture, deforestation, pollution.
10. Sea wall: Concrete structure reflecting wave energy to prevent erosion/flooding.
11. Managed retreat: Allowing the sea to flood low-value land to create natural buffers (e.g., salt marshes).
12. Soft engineering advantages: Cheaper, sustainable, works with natural processes.
13. Spit formation: Longshore drift deposits sediment where the coast changes direction or meets calm water.
14. Fjords: Glacial valleys drowned by rising sea levels (submergent).
15. Human activities: Coastal development, dredging, deforestation.

16. Wave-cut platform formation:

• Waves erode the base of a cliff via hydraulic action and abrasion, creating a wave-cut notch.
• Over time, the notch deepens, causing the cliff above to collapse due to gravity.
• The retreated cliff leaves behind a gently sloping platform of eroded rock (wave-cut platform), exposed at low tide.

17. Swash and backwash in beach formation:

• Swash (water moving up the beach) carries sediment deposited on the upper beach, contributing to its buildup.
• Backwash (water returning to the sea) transports finer sediment seaward, influencing beach gradient. Constructive waves dominate with strong swash, forming wide beaches; destructive waves have stronger backwash, causing erosion.

18. Concordant vs discordant coastlines:

• Concordant: Rock layers parallel to the coast. Erosion creates a straight coastline (e.g., Dalmatian Coast, Croatia).
• Discordant: Rock layers perpendicular to the coast. Differential erosion forms headlands (resistant rock) and bays (less resistant rock) (e.g., Swanage Bay, UK).

19. Cliff formation and retreat:

• Weathering (physical, chemical, biological) weakens cliff faces.
• Wave erosion undercuts the cliff base, forming a notch.
• Mass movement (e.g., rockfalls, slumps) causes the cliff to retreat inland, leaving a wave-cut platform.

20. Geology and cliff shape:

• Hard rock (e.g., granite): Resists erosion, forming steep, vertical cliffs.
• Soft rock (e.g., clay): Easily eroded, forming gently sloping cliffs with frequent slumping due to saturation.

21. Coral reef distribution factors:

• Warm water: Minimum temperature of 18∘C18∘C for coral polyps.
• Shallow depth: <25 m for sufficient sunlight (needed for symbiotic algae).
• Clear water: Sediment blocks light, inhibiting photosynthesis.
• Saltwater: Corals cannot survive in freshwater.

22. Mangrove root adaptations:

• Prop roots: Anchor trees in soft mud.
• Pneumatophores: Vertical roots for oxygen intake in waterlogged soil.
• Salt glands: Excrete excess salt absorbed from seawater.

23. Salt marshes and coastal defence:

• Vegetation (e.g., cordgrass) slows wave energy, reducing erosion.
• Traps sediment, raising land elevation and buffering storm surges.
• Provides habitats for wildlife (e.g., wading birds).

24. Tourism vs conservation conflicts:

• Tourism: Builds hotels, causes pollution, tramples vegetation.
• Conservation: Restricts development to protect ecosystems (e.g., coral reefs).
• Example: Overuse of Thailand’s beaches damaging mangroves.

25. Groynes causing downstream erosion:

• Groynes trap sediment moving via longshore drift on their updrift side.
• Sediment starvation downdrift increases erosion rates (e.g., Holderness Coast).

26. ‘Do nothing’ controversy:

• Advantages: Allows natural processes, creates habitats (e.g., salt marshes).
• Disadvantages: Property loss, displacement of communities (unpopular politically).

27. Bar formation:

• A spit extends across a bay due to longshore drift.
• Eventually, it connects two headlands, enclosing a lagoon (e.g., Slapton Ley, Devon).

28. Beach replenishment:

• Sand is dredged from offshore and dumped on eroded beaches.
• Limitations: Expensive (£5,000–£10,000 per metre), temporary (lasts 5–10 years).

29. Corrosion:

• Chemical weathering where seawater dissolves alkaline rocks (e.g., limestone: CaCO3+H2O+CO2→Ca(HCO3)2CaCO3​+H2​O+CO2​→Ca(HCO3​)2​).

30. Sandy vs shingle beaches:

• Sandy: Formed in low-energy environments; fine particles transported by weak waves.
• Shingle: High-energy waves deposit larger pebbles; steep gradient (e.g., Chesil Beach, Dorset).

Section C: Case Study and Diagram-Based Questions (31-40)

31. Holderness Coast retreat:

• Causes: Soft boulder clay cliffs, powerful NE waves, longshore drift removing 3.5 million m33.5 million m3 sediment/year.
• Impacts: Villages lost (e.g., Ravenspurn), £2 million spent defending Mappleton.

32. Stack formation diagram:

• 1: Hydraulic action widens a crack into a cave.
• 2: Cave becomes an arch after erosion.
• 3: Arch collapses, leaving a stack (e.g., Old Harry Rocks, Dorset).

33. Caribbean coral threats:

• Pollution: Agricultural runoff causes algal blooms.
• Overfishing: Disrupts reef ecosystems.
• Bleaching: Sea temperatures >30∘C30∘C kill algae (e.g., 2012: 8% live coral cover).

34. Longshore drift diagram:

• Waves approach at an angle (e.g., 45∘45∘).
• Swash moves sediment diagonally upshore; backwash carries it straight down.
• Net movement along coast (e.g., Holderness: sediment transported south).

35. Bangladesh’s Coastal Zone Policy:

• Planted mangroves (e.g., Sundarbans) to trap sediment, stabilise shores, and reclaim 1, ⁣290, ⁣000 hectares1,290,000 hectares of land.

36. Miami sea level rise:

• Impacts: Flooding of downtown areas, saltwater contaminating freshwater aquifers, $400 billion property at risk.

37. Conflict matrix example:

• Conservation vs Ports: Strong conflict (ports require dredging, destroying habitats).
• Tourism vs Fishing: Some conflict (tourist boats disrupt fishing grounds).

38. Sand dune succession:

• Embryo dunes: Pioneer species (e.g., sea rocket) trap sand.
• Yellow dunes: Marram grass stabilises dunes.
• Grey dunes: Soil forms, supporting shrubs (e.g., heather).

39. Rip-rap pros and cons:

• Advantages: Absorbs wave energy, cheaper than sea walls.
• Disadvantages: Ugly, boulders may shift in storms.

40. Mappleton’s defences:

• Two rock groynes and rip-rap protect the village.
• Downdrift erosion at Great Cowden accelerated (loss of 30 m/year).

Section D: Extended Response Questions (41-50)

41. Hard engineering effectiveness:

• Pros: Immediate protection (e.g., sea walls save property).
• Cons: High cost (£6,000/m for sea walls), disrupts natural processes, visually intrusive.

42. Coral reef value:

• Ecological: 25% marine species depend on reefs.
• Economic: $375 billion/year from tourism/fishing (Great Barrier Reef).

43. Coastal erosion causes:

• Natural: Destructive waves, soft geology.
• Human: Coastal development (e.g., seawalls reflect energy, increasing downdrift erosion).

44. Erosional vs depositional landforms:

• Erosional: Caves (from hydraulic action), arches (collapsed caves), stacks.
• Depositional: Beaches (swash-dominated), spits (longshore drift), bars.

45. Sub-aerial and marine interactions:

• Sub-aerial: Rainwater infiltrates cliffs, causing freeze-thaw or chemical weathering.
• Marine: Waves undercut weakened cliffs, triggering collapses.

46. Human harm and protection:

• Harm: Overfishing depletes mangroves; pollution kills coral.
• Protection: Managed retreat creates salt marshes; artificial reefs buffer waves.

47. Stakeholder conflicts:

• Space competition: Housing vs conservation (e.g., Cornwall’s AONB vs tourism).
• Resource use: Fishing vs wind farms (e.g., North Sea conflicts).

48. Mangroves and climate change:

• Carbon sinks: Store 4× more CO22​ than rainforests.
• Storm protection: Reduce wave energy by 66% (e.g., 2004 Indian Ocean tsunami).

49. Coastal management examples:

• Holderness: Hard engineering protects Mappleton but shifts erosion.
• Bangladesh: Soft engineering (mangroves) sustainably reclaims land.

50. Quadrat use in beach transect:

• Place a 1 m21 m2 quadrat at regular intervals (e.g., every 10 m) from low to high tide.
• Record pebble size (using ruler) and shape (Power’s Index). Calculate mean size per zone.