Edexcel IGCSE Geography: Coastal Processes & Landforms

Contents

• Coastal Processes
• Coastal Landforms
• Coastal Environmental Change

Coastal Processes

Wave Action & Erosion

• Coasts are open systems involving inputs, transfers, stores, and outputs.
• Processes:
  • Marine (offshore) processes
  • Terrestrial (onshore) processes
  • Wave action
  • Erosion
  • Transportation
  • Weathering
  • Mass movement

Wave Action

• Waves are formed by wind and involve erosion, transport, and deposition.
• Wave characteristics depend on:
  • Fetch
  • Wind duration
  • Wind strength
• Swash: water moving up the beach.
• Backwash: water returning to the sea.

Types of Waves

• Constructive Waves:
  • Strong swash, weak backwash
  • Long wavelength, low height, low frequency
  • Form gently sloping beaches
• Destructive Waves:
  • Weak swash, strong backwash
  • Short wavelength, high height, high frequency
  • Form steep beaches

Erosion

• Types of coastal erosion:
  • Hydraulic action: Force of waves
  • Attrition: Material in waves collides and smooths
  • Corrosion: Dissolving of rock by acidic water
  • Abrasion: Material hurled at the coast
• Factors affecting erosion:
  • Energy
  • Materials
  • Shore geometry

Transportation & Deposition

• Material sources: cliffs, longshore drift, waves, river discharge.
• Longshore Drift:
  • Transport of material along the coast by waves.
  • Influenced by prevailing wind.
• Deposition occurs when wave energy decreases.

Weathering

• Breakdown of rocks without movement.
• Types:
  • Mechanical (e.g., freeze-thaw, salt weathering)
  • Chemical (e.g., dissolution by acidic rainwater)
  • Biological (e.g., plant roots, organisms)

Mass Movement

• Downhill movement influenced by gravity, rain, slope angle, vegetation, etc.
• Types:
  • Soil creep
  • Flow
  • Slide
  • Fall
  • Slump

Coastal Landforms

Erosional Landforms

• Headland and Bay: Formed by differential erosion of resistant and less resistant rock.
• Cove: Formed on concordant coastlines through erosion of softer rock.
• Cliffs and Wave-Cut Platforms: Formed by erosion at cliff bases.
• Cave, Arch, Stack, Stump: Sequential formation through erosion and weathering.

Depositional Landforms

• Beach: Formed in sheltered areas by constructive waves.
• Spit: Extended sand/shingle out to sea; may have a hooked end.
• Bar: Sand formation joining two headlands.
• Lagoon: Water body cut off by a bar.
• Tombolo: Spit joins mainland to an island.
• Barrier Island: Formed parallel to coast.

Coastal Environmental Change

Influence of Geology

• Softer rocks form low landscapes; harder rocks form rugged landscapes.
• Rock type impacts cliff shape and characteristics.

Influence of Vegetation

• Vegetation stabilizes and fixes landforms.
• Adapted to coastal conditions and salt levels.

Sea-Level Changes & Human Influence

• Sea-Level Changes:
  • Submergent coastlines with rias and fjords.
  • Emergent coastlines with raised beaches, caves, arches.
• Human Activity:
  • Coastal settlements
  • Economic development
  • Coastal management