Coastal Change And Conflict

Question 1

Define discordant coastline

Answer 1

When the coastline consists of two types of rock (soft and hard rock) which is perpendicular to the sea

Question 2

Define concordant coastline

Answer 2

When the coastline is parallel to the sea and only made up of one type of rock

Question 3

How do headlands and bays form?

Answer 3

The different rates of erosion of a discordant coastline as soft rock erodes at a quicker rate creating bays and hard rock erodes at a slower rate forming headlands.

Question 4

How do wave cut platforms form?

Answer 4

Occurs on a concordant coastline in soft rock

• A joint forms in the soft rock and is made bigger through hydraulic action
• This forms a wave cut notch which is made bigger through hydraulic action and abrasion
• This makes the rock above the wave cut notch become unsupported so it falls down due to gravity
• This process continues to make the cliff recede and retreat creating a wave cut platform

Question 5

How do stacks and stumps form?

Answer 5

• A crack I’d made bigger by hydraulic action
• This forms a cave which is made bigger through hydraulic action and abrasion
• This forms an arch. This leaves the overhang unsupported so it falls down due to gravity creating a stack
• When the stack has eroded, it forms a stump

Question 6

How is a spit formed?

Answer 6

Long shore drift moves the sediment in the direction of the prevailing winds forming a spit. The original coastline has a headland formed from the hard rock and a salt marsh forms behind the spit

Question 7

How is a lagoon formed?

Answer 7

Forms behind a bar

Question 8

How is a bar formed?

Answer 8

When the spit is joined to another piece of land across a bay formed by soft rock

Question 9

What hard engineering coastal defences are there?

Answer 9

• Groynes
• Gabions
• Recurved sea wall
• Rip Rap/ Rock armour

Question 10

What soft engineering coastal defences are there?

Answer 10

• Beach replenishment

- Slope stabilisation

Question 11

What are gabions?

Answer 11

Metal cages filled with rocks to absorb the waves energy to decrease erosion
Advantages- cheap
Disadvantages- not very strong so cages can break adding to the sea eroding the cliff as abrasion

Question 12

What are groynes?

Answer 12

They are wooden fences that trap sediment stopping erosion.
Advantages- lasts a long time
Disadvantages- disrupt long shore drift causing other coastlines to erode more, looks unnatural and ugly for tourists

Question 13

What is beach replenishment?

Answer 13

The addition of sand on a beach to decrease erosion
Advantages- looks natural and attractive for tourism, cheap
Disadvantages- Has as to be replaced every 2 years, continues to erode

Question 14

What is a recurved sea wall?

Answer 14

A wall that protects the cliffs from erosion by reflecting the waves energy back into the sea
Advantages- acts as a promenade for local citizens and tourists to walk on, visible making people feel safe, durable as it lasts for many years
Disadvantages- looks unnatural, expensive to install and maintain

Question 15

What is rip rap or rock armour?

Answer 15

Rocks placed at the base of the cliff to protects it form erosion
Advantages- extremely cheap, in effect for many years
Disadvantages- looks unnatural and unattractive for tourists

Question 16

What are the coastal management strategies?

Answer 16

• Strategic Realignment- no additional costs, expensive to relocate people
• Do nothing- no additional costs, lets nature take its course, expensive to relocate people
• Hold the line- costs to install coastal defences, protects the coastline from eroding and keeps residents and coast safe
• Advance the line- costs to install coastal defences further into the sea, increases land value, protects it from further and current erosion

Question 17

What is weathering?

Answer 17

The wearing away of rocks

Question 18

What is biological weathering?

Answer 18

When wildlife breaks into the rocks weakening it

E.g. Tree roots push part the rocks

Question 19

What is chemical weathering?

Answer 19

When a chemical reaction occurs between rocks and rain or sea water.
E.g. Acid rain from sulphur dioxide being dissolved in water then vaporised into clouds which creates acid rain which weakens rocks

Question 20

What is physical weathering?

Answer 20

When environmental changes such as temperature changes and freeze thawing weakens the rock

Question 21

What are the differences between constructive and destructive waves?

Answer 21

Constructive waves- strong swash, weak backwash, shorter, less frequent, build up the beach
Destructive waves- weak swash, strong backwash, taller, more frequent, erode the beach

Question 22

How does climate change increase the risk of coastal flooding?

Answer 22

As the earth gets warmer, the particles in the sea vibrate taking up more space causing the sea to expand and for sea levels to rise. This increases the volume of the sea so it is more likely for coastal flooding to occur.
Increased storm frequencies also occur because of climate change as the earth is getting warmer so the sea becomes warmer making more rising hit air forming for clouds thus storms