Coastal Landscapes in the UK

• What are the two types of waves?


  Constructive and destructrive
• What are some characteristics of constructive waves?


  • Strong swash, weak backwash
  • Low wave height, large wavelength
  • Low frequency
  • More depositional
• What are some characteristics of destructive waves?


  • Strong backwash, weak swash
  • High wave height, small wavelength
  • High frequency
  • More erosional
• What factors does the size of a wave depend on?


  • Strength of wind
  • How long the wind blew for
  • Water depth
  • Fetch - distance waves have travelled from origin
• What type of waves have the longest fetch?

  Destructive waves
• What is erosion?


  Removal and destruction of rocks and sand along the coastline
• Explain the creation of caves, arches, stacks, and stumps


  1. Occurs on headlands
  2. Hydraulic action and abrasion widens cracks at base of headland to create a cave
  3. Erosion continues, deepening the cave until it erodes through to form an arch
  4. The top eventually falls due to gravity to leave stacks
  5. Marine erosion continues at the base to create a stump
• How does longshore drift occur?


  1. Sediment travels by swash in the direction of the prevailing wind at a 45° angle
  2. Backwash moves sediment back down because of gravity at a 90° angle
  3. This repeats overtime to transport sediment
• What is deposition?


  A wave loses energy so the sediment is carries becomes too heavy and so it is dropped
• What are examples of depositional landforms?


  • Beaches
  • Spits
  • Bars
  • Sand dunes
• What are beaches?


  • Large deposits of sand and shingle from constructive waves
  • Typically have berms - ridges which high tides reach
• What are spits?


  • Long narrow strip of land formed from longshore drift
  • Wave loses energy because of differing direction of water and deposits sediment
  • Prevailing wind may cause a hook to appear
  • Sheltered area behind a spit may turn into a salt marsh
• What are bars?


  • A spit that has grown across the mouth of the bay, creating a lagoon behind it
  • Lagoon will become a freshwater lake
• What are sand dunes?


  • Prevailing winds blow sediment to the back of the beach
  • Embryo dunes: found in the upper beach area where sand accumulates around a small obstacle
  • Yellow dunes: Vegetation develops and stabilises the dune
  • Grey dunes: Vegetation dies and returns nutrients to soil
  • Dune slack: Moisture-loving plants grow due to water being trapped between hollows
• What are the three types of weathering?


  • Mechanical weathering: breakdown rocks due to exertion of physical forces
  • For example: Freeze-thaw weathering where the expansion of water expands cracks in rock
  • Chemical weathering: breakdown through chemical reactions
  • For example: Carbonation where acid rain reacts with calcium carbonate
  • Biological weathering: breakdown by plants, bacteria, and animal
• What does the type of mass movement depend on?


  • The angle of the slope
  • Rock type
  • Saturation of ground from rain/flooding
• What are the different types of mass movement?


  • Rockfall: Rocks fall off sloped cliffs from mechanical weathering
  • Landslides: Water between rock reduces friction and allows rocks to fall down a straight slope
  • Mudslide: Saturated soil falls down straight slope to form a bulging lope
  • Rotational Slip: Like mudslides but on a sloped cliff which creates steps
• What is managed retreat?


  Allowing coastal areas to flood to avoid more homes being damaged
• What are methods of soft engineering for coasts?


  • Dune stabilisation
  • Beach nourishment
• What is dune stabilisation?


  Marram grass and vegetation is planted to bind dunes to protect the land behind it
• What are the advantages of dune stabilisation?


  • Cheap
  • Creates wildlife habitat
  • Minimum impact on environment
• What are the disadvantages of dune stabilisation?


  • Planting is time consuming
  • Can easily be damaged by weather
• What is beach nourishment?


  Sand is added to the beach to replace material that is lost
• What are the advantages of beach nourishment?


  • Maintains beaches which may be tourist attraction
  • Blends in with the rest of the landscape
• What is a disadvantage of beach nourishment?


  Large quantities of sand needed regularly
• What are hard engineering methods that can be used to defend coasts?


  • Groynes
  • Sea walls
  • Rock armour
  • Revetments
• What are groynes?


  Rock or wood that prevents longshore drift and traps the sediment
• What are some advantages of groynes?


  • Builds up beach and protects tourist attractions
  • Cheaper
• What are some disadvantages of groynes?


  • Visually unappealing
  • Deprives areas along the shore of sediment
• What are sea walls?


  Concrete walls that absorb and reflect wave energy
• What are some advantages of sea walls?


  • Effective erosion prevention
  • Has a promenade which creates tourism
• What are some disadvantages of sea walls?


  • Visually unappealing
  • Expensive to build and maintain
  • Wave energy reflected somewhere else
• What is rock armour?


  Large rocks reduce wave energy but allow water through
• What's an advantage of rock armour?


  Cheaper
• What are some disadvantages of rock armour?


  • Rocks don't fit in with local geology
  • Poses a hazard
• What are revetments?


  Wooden/concrete ramps that absorb wave energy
• What's an advantage of revetments?


  Cheaper
• What are some disadvantages of revetments?


  • Visually unappealing
  • Needs constant maintenance