Why are coastlines important in the UK?
Here in the UK, we have a coastline over 12,000 km long.
Social - Residential areas = emotional attachment to the area.
- Recreational activities = happy/ healthy community
Economic –Tourism = brings money into local community
through employment and
hotels etc.
- Fishing = fish are sold for money that people spend
in local area.
Environmental –Provides habitats for animals = breed
Waves
A wave is a movement of energy through water, not a movement of water. The size of
the waves depend on 3 factors;
•The FETCH (the distance the wind blows over the water) –The greater the fetch,
the more powerful the waves will be.
•The STRENGTH of the wind
•How LONG the wind blows for
Wave characteristics Constructive waves Destructive waves
Wave height Gentle Steep
Wave length Long Short
Type of wave Spilling Plunging
Strength of swash Strong Weak
Strength of
backwash
Weak Strong
New beach
sediment
Gain Loss
How they are
created
Distant Local
Coastal Processes
Transportation - The movement of sediment along the
coast
Erosion - The breakdown of sediment into smaller
fragments
Deposition - When waves loose energy they leave
behind the smaller pieces.
•Traction - large material is rolled along the sea
floor.
Hydraulic Action –The force of water into cracks helps
to break it up.
•Saltation - beach material is bounced along the
sea floor.
Abrasion –Waves fling sand and pebbles against the
rock. These wear away like sandpaper.
•Suspension - beach material is suspended and
carried by the waves.
Attrition - Chunks of rock get knocked together and
worn into smaller bits
•Solution - material is dissolved and carried by
the water.
Solution –Water dissolves the soluble material from
the rock.
Longshore drift –A form of transportation that
moves sediment from one end of the coast to
the other.
Weathering
Weathering is when rocks are broken down. There are 3 types of
weathering;
Mechanical (physical) –When rocks break up due to water entering
the cracks and freezing and thawing, making the rock weak.
Chemical –Caused by chemical changes. Slightly acidic rainwater
slowly dissolves certain rock types
Biological –Plant roots grow causing cracks in the rocks and animals
burrow into weak rocks like sand.
COASTS
YEAR 8
Landforms of Erosion
Headland and Bay –form along coastlines where there are alternating
outcrops of resistant (harder) and less resistant (softer) rock. The softer
rock erodes faster than the harder rock.
Cave, Arch, Stack and Stump -
Caves occur when waves force their way into cracks in the cliff face.
Eventually it will break through to the other side forming an arch. The arch will
gradually become bigger until it can no longer support the top of the arch.
When the arch collapses, it leaves the headland on one side and a stack (a tall
column of rock) on the other. Overtime, it will eventually collapse to form
a stump.
Landforms of Deposition -
Beach - Found between areas of high and low tide marks. Generally
formed by constructive waves.
Sand dunes - Mounds of sand that are found behind sandy beaches. To
form they require a large flat beach, a good supply of sand, strong wind
and obstacles.
Spit - Sediment is carried by longshore drift. When there is a change in
the shape of the coastline, deposition occurs. A long thin ridge of
material is deposited.
Bar –When a spit continues to attach two headlands
Tombola - a spit connecting an island to the mainland
Management of the coast
Hard engineering - using artificial
structures such as sea walls to control
natural processes
Groynes - wooden or stone fences that
are built at right angles to the beach.
They trap sediment being moved by
longshore drift and enlarge the beach.
✅Traps material and therefore
reduces longshore drift
✅Reduces flooding rate
❌Unnatural and ugly
Rock Armour - Large boulders placed
along the coast. The rocks force the
wave to break, absorbing their energy
and protecting the coastline.
✅Reduces erosion
✅Reduces flooding.
❌Unnatural and ugly
❌In storms it can be moved
Sea Wall –A large concrete, often
curved, wall that reflects the energy
back from waves
✅Creates a promenade for
people to walk along
✅Reduces flooding.
❌Unnatural and ugly
❌Expensive
Soft engineering is using natural processes to protect the coastline.
Beach Replenishment - The addition of sand or shingle to an existing beach to make it higher
or wider.
✅Relatively cheap and easy to maintain
✅Blends in with existing beach
❌Needs constant maintenance
Dune regeneration - Sand dunes are effective buffers to the sea but are easily damaged and
destroyed by trampling.
✅Maintains a natural coastal environment
✅Relatively cheap
❌Needs constant maintenance
