Coastal change and conflict

Question 1

What is the coastal zone?

Answer 1

The dynamic, constantly changing zone between the land and sea.

Question 2

Give one example of and describe 3 features of a hard rock coast.

Answer 2

Lands End, Cornwall

1) Cliffs are high,steep and rugged
2) Cliff face is often bare with no vegetation and little loose rock.
3) A few boulders and rocks have fallen from the cliff at the foot of the cliff face.

Question 3

Give one example of and describe the features of a soft rock coast.

Answer 3

Scarborough, Yorkshire

1) May be high, but are less rugged and not so steep.
2) May be piles of mud and clay which have slipped down the face of the cliff.
3) At the foot of the cliff, there are very few rocks, some mud and sand.

Question 4

Name three erosive processes and describe them.

Answer 4

1) Hydraulic action - Water is forced into cracks in the cliff face, this compresses the air so that when the wave retreats the air blasts out which can force the rock apart.
2) Abrasion - Loose rocks called sediment are thrown against the cliff by waves this wears the cliff away and chips bit of rock off the cliff.
3) Attrition - Loose sediment is swirled around by waves, the sediment constantly collides with other sediment and is gradually worn down into rounder smoother sediment.

Question 5

How is a wave cut platform formed? (4)

Answer 5

1) The sea attacks the base of the cliff forming a wave-cut notch.
2) The notch increases in size causing the cliff to collapse.
3) The process repeats and the cliff continues to retreat.
4) A wave-cut platform is left at the bottom, exposed at low tides.

Question 6

What is a discordant coastline?

Answer 6

A discordant coastline consists of different layers of rock at right angles (perpendicular) to the coast.

Question 7

What is a concordant coastline?

Answer 7

A concordant coastline consists of the same rock type along the whole coastline, parallel to the coast.

Question 8

How are caves, arches, stacks and stumps formed? (4)

Answer 8

1) Weak areas in a headland are attacked by waves and open to form a cave.
2) Cave widened and deepened by erosion and breaks through headland to form an arch. e.g. Durdle door, Dorset.
3) The arch is continually eroded and eventually collapses leaving an isolated stack.
4) The stack is eroded forming a stump.

Question 9

On what sort of coastline are bays formed and how are they formed?

Give an example of this sort of coastline.

Answer 9

Discordant coastlines, South-West Ireland
Bays are formed when a band of weaker rock is surrounded by two bands of hard rock. The soft rock erodes much faster than the hard rock creating bays, the hard rock is left sticking out as headlands.

Question 10

On what sort of coastline are coves and cliffs formed and how are they formed?

Answer 10

a

Question 11

What are the characteristics of summer constructive waves? (3)

Answer 11

1) Small, long wavelengths and low amplitudes.
2) Strong swash so transport sand up the beach and deposit it - build up the beach.
3) This creates a gently sloping beach profile.

Question 12

What are the characteristics of winter destructive waves? (4)

Answer 12

1) Big, shorter wavelength and larger amplitude.
2) They have strong backwash, which erodes sand from the beach.
3) This creates a steep beach profile.
4) The sand is carried offshore by an underwater rip current and is deposited out at sea, forming an offshore bar.

Question 13

What causes waves?

What does the size of waves depend on? (3)

Answer 13

When wind blows across the sea, friction between the wind and the water surface causes waves.

The size of waves depends on:

1) The strength of the wind.
2) How long the wind blows for.
3) The length of water the wind blows over - called the fetch.

Question 14

What is backwash?

What is swash?

Answer 14

The movement of a wave retreating back to sea, away from the beach.

The movement of a wave onto and up the beach, when a wave breaks.

Question 15

Explain the process of longshore drift. (4)

Answer 15

1) Longshore drift is the process by which sediment is carried along a coastline.
2) Waves can break at an angle due to the direction of the prevailing winds.
3) The swash carries material up the beach at an angle and the backwash then flows back to the sea at 90º.
4) Prevailing winds are usually from one direction, longshore drifts are usually in one direction too.

Question 16

How is a spit formed? (3)

Answer 16

1) Longshore drift carries sand along the shore until it reaches a river estuary, where it gets pushed out into the river channel.
2) The river flow halts the drift, so sand is deposited, forming a long sandy neck, called a spit.
3) The spit stops growing when the deposition of sand by longshore drift is balanced by erosion from the river.

Question 17

What is a bar?
How can bars affect bays and how are bars formed?
How does the end of a bar become recurved?

Answer 17

A bar is a depositional landform which joins two sections of mainland.
Small bays can sometimes be blocked by a bar of sand which grows across the mouth of the bay due to longshore drift.
The end is curved by wind and waves.

Question 18

What is a tombolo?

Answer 18

A tombolo is where sediment joins the mainland to an island.

Question 19

What is a storm surge?

Answer 19

This occurs when a a spring tide and a low air pressure coincide, a storm surge is when huge waves flood the coast.

Question 20

What is hard engineering?

What is soft engineering?

Answer 20

Hard engineering options tend to be expensive, traditional building structures. They may also have a high impact on the landscape or environment and be unsustainable.

Soft engineering options are often less expensive than hard engineering options. They are usually more sustainable, with less impact on the environment.

Question 21

What are the benefits (3) and drawbacks (2) of sea walls?

Cost of sea wall?

Answer 21

Benefits:
1) They deflect the waves energy away from the coast
2) Protects the base of the cliffs, land and buildings from erosion.
3) Can provide promenade for people to walk along the beach.
Drawbacks:
1) Cost of installation and maintenance is high.
2) Overtime the wall may begin to erode

Cost = £2000 per metre

Question 22

Give 2 benefits and 3 drawbacks of groynes.

Cost of groynes?

Answer 22

Benefits:
1) Prevents the movement of beach material along the coast by longshore drift.
2) Allows the build up of beach, beaches are a natural defence against erosion and attraction for tourists.
Drawbacks:
1) They look unsightly.
2) They are expensive to install and maintain.
3) They may increase erosion downdrift.

Cost = £2000 per metre

Question 23

Give 3 benefits and 1 drawback of Rip-rap.

Cost of Rip-rap?

Answer 23

Benefits:
1) They are effective at absorbing the energy of waves.
2) They look natural.
3) Easy to build.
Drawbacks
1) Can be expensive to obtain and transport the boulders.

Cost = £300 per metre

Question 24

Give four soft engineering approaches to coastal management.

Answer 24

1) Planting vegetation to make the cliff more stable.
2) Beach nourishment - put fresh sand onto the beach, must be protected from LSD but a larger beach dissipates wave energy, reducing erosion.
3) Offshore breakwaters - force the waves to break before they reach the beach.
4) Cliff regrading - making the cliff face longer so that it is less steep.

Question 25

What is holistic management?

What three things does holistic management take into account?

Answer 25

Holistic management involves managing the whole coast and not just one place.
Holistic management takes into account:
1) The needs of different groups of people.
2) Economic costs and benefits.
3) The environment of land and sea.

Question 26

What is an SMP?

What does ICZM stand for?

Answer 26

An SMP is a shoreline management plan for long stretches of coast, i.e. it will prevent groynes being built in one area if it will affect the coast further down.
Integrated Coastal Zone Management.

Question 27

Name the four choices councils have when managing the coast.

Answer 27

1) Hold the line - use sea defences to stop erosion, and keep the coast where it is today, this is expensive.
2) Advance the line - use sea defences to move the coast further into the sea, this is very expensive.
3) Strategic retreat - gradually allow the coast to erode and move people and businesses away from at risk areas, this involves compensation to people when their homes are lost.
4) Do nothing - take no action at all, let nature take its course.

Question 28

Case study - Hard Engineering

Answer 28

Bishopstone protected

Rip-rap and sea wall

Question 29

Holderness case study, why is it prone to erosion?(5)

Attempts at coastal management. (4)

Answer 29

1) Cliffs are made of soft glacial material.
2) Shoreline very exposed, approaching waves have a very long fetch.
3) The waves are mainly destructive.
4) Beaches are narrow and do little to protect the coastline.
5) Sea-level rise

1) Groynes to protect beach material.
2) Sea walls to protect cliffs from erosion
3) Breakwaters to force waves to break offshore
4) Sea wall to protect Easington gas station

Question 30

Impacts of Coastal management case study. (3)

Answer 30

Mappleton - groynes constructed here

1) South of Mappleton longshore drift continues to happen but there is no fresh beach material is replacing it, so erosion is worse downdrift.
2) Has accelerated cliff erosion south of Mappleton 10m/year.
3) Beaches have become narrower and cliffs are unprotected south of Mappleton.