Please enable JavaScript.
Coggle requires JavaScript to display documents.
Geography - Coasts (Coastal Erosion and Transportation (Transportation…
Geography - Coasts
-
Caves, Arches, Stacks and Stumps
-
Arch will be made wider at the base due to erosion. Top will also be weakened by weathering processes.
-
-
Starts with a crack in the headland, this is made larger by erosion.
-
-
-
-
-
Wave Strength, Constructive and Destructive Waves
Constructive waves
Large swash, small backwash. Adds material to the beach. 6-9 waves per minute.
Destructive waves
Small swash, large backwash. Material removed from the beach. Steep beach produced. 11-15 waves per minute.
-
Weathering Processes
-
Biological – Burrowing animals, tree roots, animal droppings
-
Mass Movement
Slumping – Cliff is made of two types of rock. Top layer is permeable and water soaks through. Water reaches under layer which is impermeable. Top layer slides over the top due to water acting as a lubricant and weight of the cliff.
Sliding – Only one type of rock, and material slides down the cliff.
Rock Falls – Happens on steep cliffs made of hard rock. Can happen when freeze thaw weathering occurs or waves undercut the cliff.
Depositional Landforms – Beaches, Spits and Bars
Spits – Finger of land sticking out to sea. Longshore drift brings material to a change in shape of headland. Material is deposited. Over time, more material builds up and new land is created. Spit has a curved end as 2nd most common wind direction pushes material around. Salt marsh develops behind the spit.
-
Beaches are found in bays. If longshore drift happens – drift aligned beach. If waves arrive at 90 degrees to the beach – swash aligned beach.
Hard Engineering – Sea Walls, Groynes, Rip Rap
Groynes – Trap sediment and slow longshore drift. Need maintenance as they rot. Can be ugly. Makes beach bigger which may be good for tourism.
Rip rap – large boulders resistant to erosion, cheap and easy to maintain. Can stop access to the beach, don’t look attractive
Sea Wall – Very expensive, very effective. Includes a promenade – good for tourism. Can block access to the beach and can be ugly.
-
Soft engineering – Beach nourishment, sand dune regeneration
Beach nourishment – material added to the beach, absorbs the power of the waves. Looks natural. May need to be re-done regularly as it could be removed in a storm event.
Dune regeneration – planting vegetation to hold the dune together, absorbs the power of the waves. Can easily be damaged by trampling. Looks natural. Takes a long time to be effective.