1. Things you should know off
by heart!
When I saw off by heart I mean
anything that’s written in this
PowerPoint you should be able to write
in your exam!!

2. Constructive and Destructive
Waves
• At least two differences between
constructive and destructive waves e.g.
– Constructive waves are long, low waves that
build up the beach.
– Destructive waves are much more frequent
waves with a shorter wave length and erode
the beach.

3. Erosion
• Hydraulic action – air gets forced into cracks
and then pops like air from a champagne bottle
• Abrasion – rocks hit the cliff
• Attrition – rocks hit other rocks wearing each
other away
• Corrosion – sea water dissolves the rock

4. Mass Movement
• Bottom of the cliff eroded by waves
and undercut
• Rainfall saturates cliff and makes it
heavier
•Rocks slide down cliff
•Often happens in clay
• Rocks are weathered on the cliff face
• They break loose and fall under the influence of gravity

5. Wave Cut Platforms
• Hydraulic action
erodes the coastline
causing undercutting.
• Rocks above the notch
are unsupported and
collapse.
• The rocks from the cliff
are eroded by abrasion
and attrition causing a
wave cut platform.
• The cliff retreats inland

6. Rate of cliff recession
• The longer the fetch, the further the wave
has to travel. It picks up more energy and
so erodes the cliff quicker
• The softer the geology (rock) the easier it
is to erode so cliff recession happens
more quickly

7. Cave, arch, stack, stump

8. Longshore Drift
• The direction of the
wind forces waves
onto the beach at an
angle
• Swash carries
sediment (sand and
rocks) up the cliff
• Backwash pulls
material off the
beach under
gravity.
• Sediment is
transported along
the coast

9. Formation of a spit
• Longshore drift carries material along the
coastline
• When the coastline changes direction,
longshore drift continues and extends the beach
into open water
• The end of the spit often becomes curved
because of changes in the wind direction
• Sediment often builds up in the sheltered water
behind the spit to form a salt marsh

10. Effects of coastal recession
Human
• Loss of land
• Loss of property and belongings
• Insurance has to pay out a lot of money
Environmental
• Loss of habitat for animals
• Loss of breeding grounds for birds

11. Coastal Flooding and Protection
Thames Barrier build to protect the city of People in Bangladesh plan for flooding by
London. Barriers closed during bad building their houses on stilts. This
weather and high tide to protect peoples protects their houses and belongings.
businesses and property.
Met office predicts heavy rain. People can ring Floodline to see
if their property is at risk. Can then protect property with sand
bags, evacuating or moving belongings upstairs.

12. Hard Engineering
• Groynes – stop longshore drift
• Revetments – protect the cliff and capture
sediment
• Seawall – protects the cliff
• Riprap – absorbs wave energy and
protects the cliff
• Offshore reefs – absorb wave energy to
allow a wide beach to develop.

13. Soft Engineering
• Beach replenishment – taking sand from
the bottom of the ocean and putting it back
on the beach
• Managed retreat – coastal erosion is
allowed to happen
• Cliff regrading – making the cliff face
longer and less steep to stop slumping.

14. Coastal Protection - You should know at least 2
advantages and 2 disadvantages for hard and soft
Hard Engineering Soft Engineering
Advantages Advantages
(1) protects the land and (1) Looks completely natural
buildings behind the cliff. (2) Managed retreat and cliff
(2) absorb wave energy and regrading are much
stop material from the cheaper
beach being eroded.
Disadvantages
Disadvantages (1) Erosion will continue to
(1) Very expensive to build happen
and maintain (2) They have be to replaced
(2) They often look ugly much more often

15. Swanage
Swanage is build on clay which is susceptible to
erosion. To protect Swanage:
• A seawall was built as a barrier to wave attack
• The cliff was regraded to prevent slumping
• A series of groynes were installed to reduce
longshore drift.
• 90000m3 of sand was pumped onto the beach.