depositional landforms

Question 1

what are sand dunes?

Answer 1

a mound of sand formed by the wind usually along on a beach or in a desert

Question 2

what is an example of sand dunes?

Answer 2

Camber sands on the eastern end of the east sussex coast
only sand dune system in east sussex
1km long
site of special scientific interest (SSSI)

Question 3

how much sand is deposited in camber sands each year

Answer 3

7,500 cubic metres, trapped by the accreting dune system

Question 4

natural factors creating camber sands?

Answer 4

• increased amount of fluvial input of sand around 350 years ago
• SW winds create a fetch under 200km, limits formation of destructive waves
• oreintation of coast means SW prevailing wind causes saltation to move sediment up beach during low tide (also macrotidal range)
• xerophytic and halophytic marram grass lowers wind speed and binds sand to form yellow dunes

Question 5

anthropogenic (human) factors creating camber sands?

Answer 5

• deforestation and changes in farming due to agarian revoloution in 1700’s increased surface run off levels of River Rother drainage basin, with this more erosion has brought more sediment to the coast.
• 1894 golf course, followed by camber village hems in the dunes
• 1967 sand mining of beach material to build dungeness power station
• 1940’s sand dunes used for military practise for D day landings

Question 6

how are saltmarshes formed?

Answer 6

1) in an estuarine environment where the river meets the sea, an electrical charge is given of which leads to small clay partciles sticking together, consequently increasing in mass and sinking. this is called flocculation and forms mudflats
2) pioneer species such as green algae and spartina develop, binding the mud together and encouraging more deposition
3) formation of sword zone (flooded 4 out of every 12 hours), floods less so other species such as salicornia develops
4) then upper sword zone develops (flooded only by spring tides)
5) land gets so high it never floods, salinity washed out of soil and climactic climax vegetation develops.

Question 7

example of saltmarsh?

Answer 7

Abbots Hall farm

Question 8

how can barrier beaches be formed?

Answer 8

LSD causes sediment to increase and grow the spit all the way across the bay
or, barrier islands migrate towards the coast due to washover

Question 9

what is washover?

Answer 9

high tidal surges cause erosion on the seaward side of the barrier island. sediment is deposited on the landward side of the barrier island. over time this process moves the islands closer to the coastline.

Question 10

how can barrier islands be formed?

Answer 10

flood water seperates sand dunes from the mainland
barrier beach (bar) falls apart due to a decreased supply of sediment

Question 11

what is equifinallity?

Answer 11

when a landscape feature can be made in multiple ways.