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Coastal Environments. Sand Dune Systems. Coastal Dunes. Temperate latitudes. Accumulation of windblown sediment needed in backshore zone. UK - around 7-8% of coast has vegetated dunes. Needs vegetation, low rainfall, strong winds and abundant sand. Sand Movement. Saltation
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Coastal Environments Sand Dune Systems
Coastal Dunes • Temperate latitudes. Accumulation of windblown sediment needed in backshore zone. • UK - around 7-8% of coast has vegetated dunes. • Needs vegetation, low rainfall, strong winds and abundant sand. Lindsey Wood, liw2, 022423830
Sand Movement • Saltation • sand blown downwind. Transfers energy through other grains. • 75% of sand moved by this method. • Surface Creep • By product of saltation. • Pushed along sand surface • Must be dry Lindsey Wood, liw2, 022423830
Formation • Embryo dunes • obstacle forces deposition of sand Embryo Fore Grey • Foredunes • embryo dunes coalesce laterally • Grey dunes • includes 1st, 2nd, 3rd dune ridges etc. Growth of foredunes Lindsey Wood, liw2, 022423830
Classification Lindsey Wood, liw2, 022423830
Bay Dunes eg. Studland Spit Dunes eg. Ynyslas, see right Hindshore Dunes eg. Merthyr Mawr Ness or Forland Dunes eg. Tentsmuir Offshore Island Dunes eg. Scott Head Further Classification Ynyslas Dunes dunes http://www.bbc.co.uk/wales/mid/fun/wallpaper/pages/ynyslas_sand_dunes.shtml Lindsey Wood, liw2, 022423830
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