2.4A Waves and beach morphology

• Constructive waves = low energy waves which have a flat height

  -> Strong swash but weak backwash
• destructive waves = high energy waves which have a large height but short wavelength

  -> strong backwash but weak swash due to steep angle impact
• destructive waves impact beach morphology and sediment profiles by:

  • Weak swash and powerful backwash produces a net transport of sediment down the beach, reducing beach gradient
  • Some sediment thrown forwards in detached spray of high impact breaking wave. Accumulates above high tide mark as storm ridge.​
  • Large, pebble-sized sediment dragged down beach by backwash to form wide ridge of material below low tide mark at start of offshore zone.
• decal variation:

  • Climate change is expected to produce more extreme weather events in the UK. 
  • Winter profiles may be present for longer time over course of year
  • More frequent and more powerful destructive waves may reduce beach size