Unit 5 Coastal Conflict and Management

What you need to know:

1. Geology and landforms- types of rocks and features they make.

2. Geomorphology and processes-What processes happen?(including waves, transport, deposition)

3. Coastal erosion- How does it happen?

4. Managing the coast- Why do we bother? What conflicts can arise?

  1. THE COASTAL ZONE = ……………………………………………………………………………………….

Coasts are always changing.

  1. Draw a spider diagram to show reasons why people live near the coast. (What are the advantages?)

Ext: in a different colour list some disadvantages.

  1. The shape of a coastline can be affected by two main things: geology andwave erosion.

Geology(Rock Type)(page 70)

A example of a hard rock, resistant to erosion is: ………………… . A coastal example is ………………It will take a ………………. time to erode.

Sketch:

Add labels:

  • Steep cliff
  • No vegetation
  • A few large boulders

An example of a less resistant, soft rock is: ………………………………. A coastal example is ……………………… It takes a ……………..time to erode.

Sketch:

Add labels:

  • Less steep
  • Slips of mud and clay
  • Fine materials

ROCK STRUCTURE = the way rock types are arranged, usually in layers (strata).

(page 70 and 71)

  1. Draw and label the two types of coastline (quick sketches you can do in an exam, not a masterpiece!)

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  • Concordant Coastline – the rock type is the same along the whole coastline.
  • Discordant Coastline – different layers of rock at right angles to the coast.

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Gill Chenery

Named Example: ………………………………… Named Example:………………………………

Watch the clips and identify the Concordant and Discordant Coastline.

WAVES(page 72)

• Swash= ………………………………………………………………………………………………………………..

• Backwash=……………………………………………………………………………………………………………

• Destructive= ………………………………………………………………………………………………………

• Constructive= ……………………………………………………………………………………………………

• Fetch= ………………………………………………………………………………………………………………..

  1. Use page 72 to sketch:(quick exam sketches remember!)

Destructive Waves Constructive waves

(erode / deposit?) (erode or deposit?)

The wind blows across the sea. Friction between the wind and water creates waves. The size of the waves depends on:

  • The strength of the wind
  • How long the wind blows for
  • The length of water the wind blows over (the fetch). (WhyCornwallhas the biggest waves in England!)

Coastal landforms can be made by EROSION or by DEPOSITION.

EROSION: (MARINE PROCESSES):

  1. Watch the Coastal erosion video

Make a few notes on whilst you watch it:

Remember the anagram £CASH$ to recite the types of erosion.

  1. Watch the clip and using arrows, match up the letter with the meaning and example illustration.

C

A

S

H

EXT: Can you give named examples?

Coastal landforms:

Wave Cut notch:

  1. Add the numbers in the correct place:

Remember our Wave tank experiments! (look at the photos on the wall!)

Erosion of a Headland: Caves, Arches, Stacks and Stumps

  1. Draw your own labelled“exam sketch” version of this: (page 71 might help too). Time yourself, can you do it in 2 minutes?

At the Seven Sisters in Kent, the cliffs are 160 metreshigh and the wave-cut platform extends 540 metres out to sea!

Web animation

Erosion by Weathering: (sometimes called SUB-Aerial) (page 74)

  • Mechanical weathering- Freeze thaw water in cracks freezes, expands increases cracks in rocks causing stress and rock to fall apart:

EXT: example of a coastline where this happens ……………………..

EXT :Onion Skin weathering is another example: do you know it?

  • Chemical weathering: Co2 dissolves in water causing acidic water which can react with the minerals in rocks to dissolve it.
  • Biological weathering:roots of vegetation and burrowing animals cancause stress in rock cracks:

MASS MOVEMENT:there are 2 forms of mass movement at thecoast. Page 74)

These can dramatically change the coastline even overnight!

  • Rock fallsudden movements, rocks collect at the base
  • Slumpinghappens when the bottom of a cliff is eroded away by waves. The cliff can become weak and slide downwards. This can be triggered by heavy rain. This can be a rotational movement.

White cliffs of Dover video

  1. Why do they think this happened?

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

  1. How else can coastlines be affected? Fill in the notes below:
  • Changing sea levels and storm activity

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

  • Storms at sea causing coastal flooding

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

  1. Draw a diagram to show slumping:(2 minute labelled, exam question)

Depositional Landforms:are when SEDIMENT = (tiny clay particles, sand, silt, pebbles, boulders) are dropped, or DEPOSTITED. (more in a bit!)

LongShore Drift: (LSD) Transportation of material:

The particles of sand or shingle are transported along the beach in a zig zag movement, carried by the swash and backwash. As the prevailing wind is usually in the same direction so LSD usually is too.

  1. Draw your own quick diagram of Long Shore Drift, which you could produce in an exam:(the animations below might help too! Remember our LSD shuffle!)

(Cross reference with Holderness Coastline too!)

Annimation of LSD

Further video on LSD including what happens when a groyne is put in.

  1. Watch the clip of the Dorset(Jurassic) coast line: On the table, note down all the landforms you can see:

Look out for CONCORDANT and DISCORANT coastline!

Here are some to get you started: Spit, headland, tombolo, beach, bay, arch, stacks, Stumps etc.

Depositional Features / Erosional Features
Spit (extra web link here)

Animation of spit formation (good for Spurn Head Spit Case study Holderness)

Why does conflict occur on the coast, and how can this be managed?

  1. Read pages 76-77 in your text book to remind you about rates of coastal retreat and the effects it has on people and businesses. Make a mind map:

There are many ways to manage coastal erosion and these are split into

HARD and SOFT (holistic) ENGINEERING. (pages 80-81)

HARD ENGINEERING – traditional, building structures, costly, ugly.

SOFT ENGINEERING – working with nature. Cheaper, less intrusive.

  1. Write examples of Hard and Soft Engineering:
  1. Know the advantages / disadvantages of approaches: Complete mind maps for examples below: use different colours to summarise costs / benefits:
  1. Summarise how conflict can arise from these or other engineering methods by completing the table with some of your ideas:

FOR HARD ENGINEERING / AGAINST HARD ENGINEERING
  • ……………………………………………………………
  • ……………………………………………………………
  • ……………………………………………………………
  • ……………………………………………………………
/
  • ……………………………………………………………
  • ……………………………………………………………
  • ……………………………………………………………
  • ……………………………………………………………

Holistic management= managing the whole stretch of coast and not just one place. Holistic management takes into account:

  • The needs of different groups of people
  • Economic costs and benefits
  • The environment of land and sea

ICZM – Integrated Coastal Zone Management

SMP – Shoreline Management Plans – for long stretches of coast. This should stop one place building groynes etc if it will adversely effect down the coast.

CASE STUDY -People and property in HoldernessNE Yorkshire Coast

Where is the HoldernessCoast? What is the problem?- pg 78-79

  1. Draw the Map Holderness coast line: (30 second sketch!)

Add:

  1. Direction of LSD
  2. Spurn Head Spit
  3. Mappleton
  4. Alborough
  5. One “Lost village” and name it.
  6. River Humber
  1. Complete the case study:

The HoldernessCoast is on the ……… coast of the UK, facing the ………… Sea.

The coastline is mainly made up of cliffs (……….-30m high), consisting of soft, easily eroded ……………………………….. Where the cliff line meets the Humber Estuary, a spit has formed called ……………………. ………………….. . ……………..

The cliff line is retreating at an alarming rate - greater than ………m / yr (fastest rate in Europe) - 4km of land have been lost since Roman Times, including many villages and farm buildings.

Easington Gas Station (a North Sea Gas terminal) is under threat

Attempts at Coastal Management along the HoldernessCoast include:

  • Groynes to trap moving beach material and provide a protective beach in front of the cliff

The construction of sea walls and revetments as wave-resistant structures at the base of the cliffs

  • Rip rap forcing waves to break off-shore.
  • sea wall used to protect Easington Gas Station (cost £4.5 million)
  • Due to extensive costs - only the most valuable areas of land are protected. Much of the area is farmland which is not protected.

Example of the impacts of Coastal Management: Mappleton

In 1998, the main road running through the village was only 500m from the cliff top and in places it is now only 50m. The village is under threat due to the easily eroded boulder clay (glacial till) which makes up the cliff line. The area suffers from erosion rates of up to 2m per year.

In 1991 2 rock groynes were constructed to encourage the build up of beach in front of Mappleton by trapping longshore drift sowaves would break on the beach rather than attacking the cliffs.

Problems for further down coast

Those living south of Mappleton village have experienced the 'knock-on' effects of the coastal management.

The groynes at Mappleton have disturbed the natural longshore drift movement, trapping the coastal materials so material is still being moved south of Mappleton, but there is no fresh sediment to replace it so beaches such as Aldbrough have become even narrower and the cliffs are unprotected speeding up erosion to 10m / yr.

  1. Outline the 4 strategies for SMP. (page78)
  1. . ……………………………………………………………………………………………………………………………………
  2. . ……………………………………………………………………………………………………………………………………
  3. ……………………………………………………………………………………………………………………………………..
  4. ……………………………………………………………………………………………………………………………………..
  1. What do you think they should do?

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

Sustainable coastal management

  1. Some places are not protected because:
  • ………………………………………………………………………………………………………………………………………
  • ………………………………………………………………………………………………………………………………………
  • ………………………………………………………………………………………………………………………………………
  • ………………………………………………………………………………………………………………………………………

N.B It’s hard to convince people who’ve lived somewhere all their lives that protecting their homes is not sustainable.

GOOD LUCK

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Gill Chenery