The sea Flashcards
What are constructive waves?
Constructive waves occur during calm weather. The swash is stronger than the backwash so material is deposited.
What are destructive waves?
Destructive waves occur during stormy weather. The backwash is stronger than the swash so material is removed. (erosion)
What are the waves affected by?
Waves are affected by wind and the fetch (length of the sea)
what is the swash?
The frothy water that moves up the shore is called the swash.
What is the backwash?
The water that moves back down the shore is called the backwash.
Types of erosion - Hydraulic action
The force of the water eroding the bed and banks. (The force of the waves against rocks and cliffs)
Types of erosion - attrition
attrition is where the rocks and pebbles carried by the water crash against each other, wearing them down.
Types of erosion - abrasion
abrasion is where the rocks and moving particles carried by the water scrapes the beds and banks, eroding them.
types of erosion - solution
solution is where the rocks are dissolved by the acids in the water.
types of erosion - compressed air
Air may get trapped in the joins and cracks on a cliff. The rapped air gets compressed, which weakens the cliff and causes erosion.
Interested parties in coastal management.
There are many different land uses found in coastal areas for example:
Tourism,
Industry,
Fishing,
Trade,
Transport
Common interest groups
Local residents, environmental groups developers local counsils national government tourist boards
concerns about the coast
erosion is threatening beaches or coastal settlement.
people want to develop tourism in the area.
there is a danger of flooding if sea-levels rise.
there is a problem with sewage and/or pollution.
sea walls
sea walls are built to protect coastal towns from attack by the sea.
They have a curved top to deflect waves back out to sea.
The wall may be eroded over time.
Groynes
Groynes are low walls, often made of wood that are built at right angles to the ciast.
They help trap sand that is being moved by longshore drift.
This holds the beach in place.