COASTAL REVISION SHEET
The coast is the boundary between land and sea.
Formation of Waves
Processes of Erosion
Wave energy depends on
the fetch, the strength of
the wind and the length of
time over which the wind
has blown.
Hydraulic Action
This process involves the force of
water against the coast. The waves
enter cracks (faults) in the coastline and
compress the air within the crack.
When the wave retreats, the air in the
crack expands quickly causing a minor
explosion. This process is repeated
continuously.
Corrasion/abrasion
Material is thrown against the cliffs by
breaking waves. Cliffs are worn away
and undercut by the sandblasting
effect.
Attrition
Material carried by the waves bump
into each other and so are smoothed
and broken down into smaller particles.
Corrosion
Sea water slowly dissolves calcium
carbonate in chalk and limestone
Types of Waves
Breaking Waves
The bottom of the wave
touches the sand, slows
down and the top of the
wave topples over.
Destructive Waves
Backwash>swash
Processes of Transportation
1. Saltation pebbles are bounced along
by waves.
2. Traction boulders and pebbles are
rolled along by the waves.
3. Suspension sand and silt are carried in
suspension
4. Solution calcium carbonate is
dissolved by sea water.
5. Longshore Drift =Swash up the beach
Backwash down the beach
Processes of Deposition
Beach material is deposited by constructive waves.
Offshore deposition forms sandbars and gravel banks.
Onshore deposition forms beaches and spits.
Beach material is described by its sizeboulders, cobbles, pebbles and silt.
Landforms of Deposition
Beaches
Beaches are a build up of sand, pebbles and cobbles on a
wave-cut platform.They are formed by the transportation and
deposition of beach material
Landforms of Erosion
Headlands &
Bays
are formed in areas
with different rock
types. e.g. Swanage,
Dorset
Cliffs &
Wave-cut platform
Spits
Caves,Arches,
Stacks Stumps
Spits are curved beaches of sand and pebble that extend out into the
sea. They are formed by long-shore drift and deposition. They are
formed at a river mouth or where the coast changes direction.
Rate of cliff erosion
depends upon
Geology soft/hard
Constructive Waves
Swash>backwash
Soft Engineering
Drainage/dykes
Managed retreat
this is when areas
of little value are
allowed to flood
Advantages
Low-cost and
long-term form
of management
Disadvantages
loss of homes
roads and land
Hard Engineerin
Groynes,Gabions
Sea walls,Rip rap
Stone revetment
Advv good at
stopping erosion
and flooding.
Beaches attract
tourists
Disadv expensive
Can cause
problems in other
parts of the coast.
Coastal Management
Cliff Erosion Holderness
Coastal Flooding
Case Study
Canvey Flood 53
1. What happened?
2. What has been
done to improve
flood defences?
3. What is the
Thames Tidal
Barrier?
4. What does it do?
5. Future plans
Coastal Flooding
Case Study
Bangladesh
1. When did the
last one happen?
2. Outline of
damage caused.
3. What is being
done to improve
the situation?
4. Why are their
solutions not the
same as ours?
Tourism
Adv Local culture etc is
preserved.
Environment is protected to
attract visitors.
Provides employment and
brings in money.
Disadv local culture is lost
or watered down.
Habitats are destroyed by
building tourist resorts.
Traditional jobs are replaced
by unreliable work in the
tourists industry
Coastal Tourism
Tourism
Coastal
Scarborough
Attractions: It is near the North York
Moors National Park. 2 Sandy
beaches
Landscaped gardens & parks
Atlantis Water Park Sea Life Centre
Adv 17% employment
Makes £250-£300 million.
Locals can use the tourist attractions.
Disadv Decline in visitor numbers
because of foreign holidays.
Unemployment in off-season.
Tanzania: Zanzibar
Location: East African
Coast
Attractions: Climate,
Scenery,
Ecology, culture - Tribes,
activities- safaris,
swimming, snorkelling.
Adv incomes increased
‘Honey pot’
Disadv destroying
mangrove forests and coral
reefs.
Local fishermen hit.