Coast Essay

Coasts are controlled by nature but managed by humans.
Coasts are controlled by nature but managed by humans. Erosion and built up are the natural processes involved in controlling the coast. Due to human activities the natural processes are interrupted because humans have specific desires to use the coast in a certain way and try to manage it. Erosion occurs depending on the strength of the rock and wave. Waves carry sand, rocks, shells, seaweed and other materials on and off the beach. The hard and soft rocks allow waves and wind to create natural landforms, including caves, arches, blowholes and stacks. The eroding cliffs supply material to form sand, wind, waves, which move loose material to form beaches, sand dunes and spit.
There are two forms of waves; destructive waves, which erode the beach and constructive waves, which built up the beach. Destructive waves occur during storm conditions, when wave energy is high and the wind is powerful. The waves are larger and carry more material in the backwash to deep water. With destructive wave the backwash is stronger than the swash so more material is pulled back to the beach. When a wave breaks, the water is washed up the beach; this process is called the swash and pushes sediment up the beach away from the sea. Then the water runs back the beach, this is called the backwash and pulls beach material towards the beach.
Constructive waves occur during calm weather, when the wave is low in energy and is small. With constructive waves the swash is stronger than the backwash, so more materials such as sand, are carried to the beach as deposits. Along with constructive waves building up the beach, the process called longshore drift is also involved.
Waves usually move towards the beach at an angle and the materials are washed up the beach at the same angle by the swash while the backwash moves straight down the beach. Then the sediments are transported at the beach at an angle. This is called the longshore