PL- Coasts Flashcards
Where do sand dunes form?
Beaches
How do sand dunes form?
Obstacles such as driftwood dropped on the beach: Natural obstacles like driftwood and vegetation act as initial barriers, causing sand to accumulate around them.
Wind blows up sand which has been transported up the beach by longshore drift. It gets trapped on the obstacle: Wind transports sand from the beach inland. When the wind encounters obstacles, it slows down, causing the sand to settle and form small mounds.
Colonizing pioneer plants like marram grass grow on the dune and stabilize it: Pioneer plants, such as marram grass, begin to grow on these mounds. Their roots help bind the sand together, stabilizing the dune and allowing it to grow larger.
What are the different kinds of Dune?
Embryo, fore, yellow, grey, mature
How do wave- cut platforms form?
- Occurs at a cliff that meets the sea.
- As erosion occurs mainly where it hits land
- Proccesses (hydraulic action, abrasion) erode creating a wave-cut notch
- Eventually, once deep enough, overhang weakens (weathering)
- It then collapses leaving a platform covered in sediment (rocks)
- Once the rock is eroded away, the process repeats
- Cliff retreats leving a wave cut platform
- Slanted at a 3-4 degree angle, covered at high tide
How do headlands and bays form?
Differential Erosion: Coastlines often consist of alternating bands of hard and soft rock. The softer rock (like clay) erodes more quickly under the action of waves, while the harder rock (like chalk or limestone) is more resistant to erosion.
Formation of Bays: The areas of softer rock erode faster, creating inlets or recesses known as bays. These bays often have gentle, sweeping shorelines and can be sites of beaches.
Formation of Headlands: The harder rock erodes more slowly, leaving protruding sections of land called headlands. These headlands extend out into the sea and are typically more rugged and steep.
eg. swanage bay
How do coastal Landforms change overtime?
- Cliffs retreat
- Cracks to caves to arches to stacks to stumps
- headlands and bays retreat and round
What is a Coastal Managment Scheme?
An overall plan of coastal defences that will be used to defend an area. It may consist of hard and/or soft engineering defences.
What are some general facts about Lyme Regis?
- South coast of England
- Severe Erosion: Lyme Regis faces significant coastal erosion and landslide risks due to its unstable geology.
- Major Scheme: The Lyme Regis Environmental Improvement Scheme, costing around £43 million, included sea walls, rock armour, and beach replenishment to protect the town.
- Community Involvement: Local residents and stakeholders were involved in the planning to address concerns and ensure effective solutions.
Why did Lyme Regis need managment?
- Large number of tourists visit
- Has fossils in its cliffs
- Has unstable cliffs
- Has one of the highest erosion rates in Europe
- Has historic buildings
What are the positive effects of the Lyme Regis coastal managment scheme?
- Place still attractive to tourists
- Larger beach
- Wide promenade
- Increased number of tourists
- Harbour better protected
What are the negative effects of the Lyme Regis coastal managment scheme?
- Conflicts increased
- Increased tourism leads to more litter and congestion
- Spoilt landscape
- Interferes with natural processes
- Reduced number of fossils found
What engineering was used for the Lyme Regis coastal managment scheme?
- Rock armour
- Beach Replenishment
- Sea Wall
- Got together all interest groups to reduce conflicts
- Done in 4 stages - things would be closed, one at a time is better for tourists
