Sand Dunes

Question 1

What conditions are needed to form a sand dune

Answer 1

Sand
Space
Wind (prevailing)
Obstacle
Grass to colonise the dunes once formed
Large tidal range for sand to dry

Question 2

What is Aolian Transportation

Answer 2

Aolian Transportation is when the wind transports sediment

Question 3

What three ways can wind transport sediment

Answer 3

Suspension, Sand is picked up by the wind and accounts for, 1% of movement
Saltation , Particles picked up and dropped by the wind and bounce a long 95%, of movement
Creep, grains collide and push along other grains, 4% of movement

Question 4

How do plants survive in sand dunes?

Answer 4

Pioneer plant species e.g. sand couch and sea rocket have frictional drag because of there stems and leaves which reduce wind speeds and allow sand to accumulate
But, In some cases a dune blowout may occur as the wind is able to remove exposed sediment though delfation

Question 5

What is a Dune Blowout

Answer 5

An area of dune that has been eroded often due to it protective cover of vegetation removed by an animal or human. Leading to a dune slack being created

Question 6

Embryo Dune

Answer 6

Height: 1m
%Exposed Sand: 80
Humus and Moisture content: little mixed salt and fresh water content
Vegetation: Sand Couch, Lyme grass

Question 7

Fore Dune+ Yellow Dune

Answer 7

Height: 5m
% Exposed sand: 20
Humus and Moisture content: some humus, very little moisture
Vegetation: Marram Grass

Question 8

Grey dune

Answer 8

Height: 8-10m
% Exposed Sand <10
Humus and Moisture content: Humus increases inland
Vegetation: Some marram, Cotton Grass and Heather

Question 9

Dune Slack

Answer 9

Water is collected in the dune slack that form behind A yellow dune because it receives less sand

Question 10

Mature Dune

Answer 10

Height: 10-15m
% Exposed Sand:<10
Humus and Moisture content: Humus increases inland
Vegetation: Dune Scrub and woodland