🌊 CIE IGCSE Geography: Coasts (Comprehensive Notes)

1. 🌍 Coastal Processes

🔹 Key Definition

• Coast: The area where land meets the sea.
• Wave: Movement of energy through water, usually caused by wind.

🔹 Types of Waves

Type	Characteristics	Effect
Constructive waves	Low energy, long wavelength, strong swash, weak backwash	Build up beaches (deposition)
Destructive waves	High energy, short wavelength, weak swash, strong backwash	Erode coastlines

🔹 Marine Erosion Processes

1. Hydraulic action
   • Waves compress air in cracks → rock breaks apart
2. Abrasion (corrasion)
   • Rocks carried by waves scrape the coastline
3. Attrition
   • Rocks collide → become smaller and smoother
4. Solution (corrosion)
   • Chemical dissolution of rocks (e.g. limestone)

🔹 Transportation Processes

1. Longshore Drift
   • Movement of sediment along the coast
   • Caused by waves approaching at an angle
   • Swash moves material up the beach at an angle
   • Backwash moves it straight down
2. Other processes:
   • Traction (rolling)
   • Saltation (bouncing)
   • Suspension (floating)
   • Solution (dissolved)

🔹 Deposition

Occurs when:

• Waves lose energy
• Sediment is dropped

Conditions:

• Shallow water
• Sheltered areas (e.g. bays)

2. 🌪️ Wind Processes (Coastal Sand Dunes)

🔹 Processes

• Deflation: Wind removes loose sand
• Saltation: Sand grains bounce along surface
• Surface creep: Larger particles roll

3. 🏞️ Coastal Landforms (Erosion)

🔹 Headlands and Bays

Formation:

• Alternating hard and soft rock
• Soft rock erodes faster → bays
• Hard rock remains → headlands

Features:

• Bays: Calm water, deposition, beaches form
• Headlands: Strong wave attack, erosion dominates

🔹 Cliff and Wave-cut Platform

Formation:

1. Waves erode base of cliff → wave-cut notch
2. Cliff collapses
3. Process repeats → cliff retreats
4. Flat area left → wave-cut platform

🔹 Cave → Arch → Stack → Stump

Formation Sequence:

1. Crack enlarged → cave
2. Cave deepens → arch
3. Arch collapses → stack
4. Stack erodes → stump

👉 Classic example: Old Harry Rocks

4. 🏝️ Coastal Landforms (Deposition)

🔹 Beaches

• Formed by deposition of sand/shingle
• Found in bays (low energy)

Features:

• Berm: Raised ridge
• Storm beach: Larger pebbles at back

🔹 Spits

Formation:

• Longshore drift moves sediment
• Coastline changes direction
• Sediment deposited into sea → narrow ridge

Features:

• Often curved end (hook)
• Salt marsh may form behind

👉 Example: Spurn Head

🔹 Bars

• Spit joins two headlands
• Creates a lagoon behind

🔹 Coastal Sand Dunes

Formation:

1. Sand blown inland from beach
2. Trapped by obstacles (rocks, vegetation)
3. Stabilised by plants (e.g. marram grass)

Conditions:

• Strong onshore winds
• Dry sand supply
• Vegetation

5. 🌿 Coral Reefs & Mangrove Swamps

🔹 Coral Reefs

Conditions for Growth:

• Warm water (20–30°C)
• Shallow water (≤50 m)
• Clear, unpolluted water
• Sunlight

Types:

• Fringing reefs
• Barrier reefs
• Atolls

👉 Example: Great Barrier Reef

🔹 Mangrove Swamps

Conditions:

• Tropical climates
• Sheltered coastlines
• Muddy, low-energy environments

Importance:

• Protect coasts from erosion
• Nursery for fish
• Biodiversity

👉 Example: Sundarbans

6. ⚠️ Coastal Hazards

🔹 Coastal Erosion

• Loss of land due to wave action
• Threatens homes, infrastructure

🔹 Tropical Storms

• Strong winds + heavy rainfall
• Storm surges cause flooding

👉 Example: Typhoon Haiyan

🔹 Other Hazards

• Cliff collapse
• Flooding
• Sea-level rise (climate change)

7. 🌍 Opportunities at the Coast

🔹 Economic Opportunities

• Tourism (hotels, beaches)
• Fishing
• Ports and trade
• Renewable energy (wave/wind)

🔹 Environmental Opportunities

• Biodiversity (coral reefs, mangroves)
• Conservation areas

8. 🛠️ Coastal Management

🔹 Hard Engineering

Method	Description	Advantages	Disadvantages
Sea wall	Concrete barrier	Strong protection	Expensive, ugly
Groynes	Trap sediment	Builds beaches	Starves other areas
Rock armour	Large rocks	Absorb wave energy	Costly

🔹 Soft Engineering

Method	Description	Advantages	Disadvantages
Beach nourishment	Adding sand	Natural look	Needs repeating
Dune stabilisation	Planting vegetation	Sustainable	Time needed
Managed retreat	Allow flooding	Cheap, natural	Loss of land

9. 📍 Case Study Example (Coastal Management)

Holderness Coast, UK

👉 Holderness Coast

Opportunities:

• Farming (fertile land)
• Tourism (coastal resorts)

Hazards:

• Rapid erosion (soft clay cliffs)
• Loss of land and property

Management:

• Sea walls (e.g. at towns)
• Groynes
• Managed retreat in less populated areas

10. 📝 Exam Tips

🔑 Definitions to Memorise

• Erosion, deposition, longshore drift, hydraulic action
• Headland, bay, spit, stack, dune

🔑 Common Exam Questions

• Explain formation (step-by-step!)
• Describe processes (use key terms)
• Case study questions (include place + facts)

🔑 Answer Technique

👉 For 4–6 mark questions:

• Make 3–4 developed points
• Use connectives: because, therefore, this leads to…

👉 For 7–8 mark questions:

• Include:
  • Processes
  • Named example
  • Evaluation (advantages/disadvantages)

🔑 Quick Memory Trick

• Erosion = wearing away
• Transport = moving
• Deposition = dropping