Coastal landscapes

• Longshore Drift


  Process where prevailing wind makes waves travel at an angle, so swash hits the beach diagonally, and backwash (due to gravity) takes it straight back down, causing sediment to move in a zig-zag pattern over time
• Longshore Drift


  1. Prevailing wind makes waves travel at an angle

  2. Swash hits the beach diagonally

  3. Backwash (due to gravity) takes it straight back down

  4. Sediment moves in a zig-zag pattern over time
• Beaches, spits, bars


  • Beaches are formed when eroded material is transported by longshore drift
  • Spits are long and narrow ridges of sand or shingle, with one end attached to land
  • Bars are ridges of sand or shingle that go across the entrance to a bay or river mouth, forming a lagoon
• Hard Engineering


  Coastal protection methods like sea walls, groynes, and rock armour that are designed to prevent high tides and storm surges reaching inland and causing flooding
• Soft Engineering


  Coastal protection methods that work with natural processes
• Headlands and Bays


  • Formed by hydraulic action and abrasion eroding sea cliffs on a discordant coast, where cliffs erode at different times
  • Concordant coastlines erode at the same rate and create coves
• Caves, arches, stacks and stumps


  • caves are formed by physical weathering, hydraulic action, and abrasion
  • Caves by hydraulic action and abrasion
  • Arches by weathering and gravity
  • Stacks by erosion and weathering
  • Stumps by more erosion and more weathering
• Mass Movement


  The shifting of large amounts of rock and other loose material down a slope (like a cliff), including slumping, sliding, and rockfall
• Wave-cut Platforms


  Formed by destructive waves attacking between high and low tide marks, undercutting the cliff to form a wave-cut notch, until the overhanging cliff collapses into a wave-cut platform
• Destructive Waves


  Strong backwash, steep gradient, take away the beach
• Constructive Waves


  Weak backwash, shallow gradient, deposit sediment and build up the beach
• Coastlines can change over time due to erosion or deposition by the sea, river processes, human activity such as construction, mining, agriculture, tourism, climate change, rising sea levels, storm surges, tsunamis, earthquakes, volcanic eruptions, tectonic plate movement.
• The main types of coastal landforms are cliffs, beaches, bays, headlands, spits, bars, lagoons, estuaries, deltas, salt marshes, sand dunes.
• Human activities like building on coastlines, extracting resources from them, and altering their natural features have also contributed to changes in coastal environments.
• Climate change is causing sea levels to rise, which will lead to more frequent flooding and erosion along coastlines.
• Factors that affect the amount of deposition

  • Lots of transportation
  • Lots of erosion
  • Low energy waves
• Longshore drift


  1. Waves follow the direction of the prevailing wind

  2. They hit the coast at an oblique angle

  3. Swash carries material up the beach

  4. Backwash carries material down the beach at right angles

  5. Material zigzags along the coast
• Longshore drift


  Causes erosion at one end of the coastline and deposition at the other
• Material is transported along the coast by longshore drift
• Caves


  Waves force their way into cracks in the cliff face
• Cracks in headland


  Appear when the force of the waves crashes against the headland
• Soft engineering


  Schemes set up using knowledge of the sea and its processes to reduce the effects of flooding and erosion
• Headlands and bays


  • Form along coastlines where there are alternating outcrops of resistant and less resistant rock
• Destructive wave


  • Strong backwash
  • Weak swash
  • High wave in proportion to length
  • Tall breakers
• Destructive waves


  Erode material from the beach
• Destructive waves are created during stormy conditions, meaning they occur mostly in winter
• Constructive wave


  • Deposits material onto the beach
  • Builds up the beach
  • Created in calm weather
  • Occurs mainly in summer
• Types of erosion


  • Attrition
  • Abrasion
  • Hydraulic action
  • Solution
• Backwash


  The movement of waves and material off of a beach
• Sand dunes


  Formed when sand deposited by longshore drift is moved up the beach by the wind
• A bar forms when a spit joins 2 headlands together
• Swash


  The movement of waves and material onto a beach
• Wave frequency


  The time for one wave to travel the distance of one wave length
• Beaches are formed by deposition
• Hard engineering


  Man-made structures built to control the flow of the sea and reduce flooding/erosion
• Wave height


  The height difference between a wave crest and the neighbouring trough
• Wave length/amplitude


  The distances between successive crests
• Spits form at sharp bends in the coastline, e.g river mouth