صفحه 1:
Coastal Environments
Sand Dune Systems
صفحه 2:
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
صفحه 3:
Sand Movement
* Saltation
- sand blown downwind.
Transfers energy ‘Sand Transport Rate
through other grains.
- 75% of sand moved b
this method ‘20
: % 600
* Surface Creep 5 400
& 200 2
- By product of = 0
saltation. 0 10 20
- Pushed along sand Wind Velocity
surface + Sand Transport Rate|
- Must be dr
7 Lindsey Wood, liw2,
022423830
صفحه 4:
Formation
¢ Embryo dunes
- obstacle forces
deposition of sand 5500 Gre
* Foredunes 0 9 1
- embryo dunes
coalesce laterally
* Grey dunes
- includes 1st, 2nd,
3rd dune ridges
etc. Growth of
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foredunes 022423830
صفحه 5:
Classification
Type Morphology Vegetation
Embryo dune Unoonnected Sand Twitch & Sea
mounds, lor2m Lyme
Foredune Shore parallel Marram Grass
ridges. Up to 10m.
1* Dune ridge 10- 30m. Steep = Marram Grass
windward slope, dominant
gentler lee slope
2 Dune ridge Laryerthan 1* dune Marram Grass
ridge. Upto 30m starts to die off
Lindsey Wood, liw2,
122423830
صفحه 6:
Further Classification
۰ Bay Dunes eg. * Offshore Island
Studland Dunes eg. Scott Head
* Spit Dunes eg.
Ynyslas, see right
* Hindshore Dunes
eg. Merthyr Mawr
* Ness or Forland
Dunes eg.
4 http://www.bbe.co.uk/wales/
Tentsmuir mid/fun/wallpaper/pages/
ynyslas sand dunes.shtml
Lindsey Wood, liw2,
022423830
صفحه 7:
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Lindsey Wood, liw2,
022423830
