Coasts
DefinitionsHydraulic Action
This process involves the force of water against the bed and banks. Abrasion/Corrasion This is the process by which the bed and banks are worn down by the river’s load. The river throws these particles against the bed and banks, sometimes at high velocity. Attrition Material (the load) carried by the river bump into each other and so are smoothed and broken down into smaller particles. Corrosion (Chemical Solution) This is the chemical action of river water. The acids in the water slowly dissolve the bed and the banks. |
Coastal Transportation
Cliffs & Wave Cut Platforms- diagrams for HW
Can you recognize this famous landform of coastal deposition?
*Note the difference in deposition rates on the 2 sides of the tombolo!
How can humans control coastal erosion?
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1. Groynes
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2. Gabions
Human Interaction with Coastal Processes
Case Study- Coastal Protection in Dublin
Planners in coastal areas need to consider both EROSION and DEPOSITION when building in Coastal areas.
Dun Laoghaire-
Has a harbour with a port and a marina for smaller boats.
To protect against coastal erosion, 2 large piers were built.
This was to reduce the impact of waves especially during storms.
Rock armour has been placed on the outer part of each wall to limit erosion by hydraulic action (force of the wave.)
Dublin Port-
A seawall was built to protect Dublin Harbour from deposition and stop the harbour from silting up.
Over the past 200 years, longshore drift and constructive waves have resulted in a new landform forming called Bull Island.
Formed similarly to a sandspit, it is now 5km long and continues to grow each year.
Planners in coastal areas need to consider both EROSION and DEPOSITION when building in Coastal areas.
Dun Laoghaire-
Has a harbour with a port and a marina for smaller boats.
To protect against coastal erosion, 2 large piers were built.
This was to reduce the impact of waves especially during storms.
Rock armour has been placed on the outer part of each wall to limit erosion by hydraulic action (force of the wave.)
Dublin Port-
A seawall was built to protect Dublin Harbour from deposition and stop the harbour from silting up.
Over the past 200 years, longshore drift and constructive waves have resulted in a new landform forming called Bull Island.
Formed similarly to a sandspit, it is now 5km long and continues to grow each year.
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Quiz
- How does wind effect waves?
- What is fetch?
- Draw longshore drift. (include waterline) (3)
- Briefly explain longshore drift. (3)
- What are constructive waves?
- What are destructive waves?
- What is hydraulic action? (2)
- What is air compression? (2)
- Name one landform of coastal erosion you have studied.
- Where in Ireland can this landform be found?
- Briefly explain how this landform occurs. (include processes) (6)
- Name one landform of coastal deposition you have studied.
- Where in Ireland can this landform be found?
- Briefly explain how this landform occurs. (include processes) (5)
- Explain why the west coat of Ireland is more indented than the East Coast.