Case Studies

Coastal erosion – physical and human causes and physical and socio-economic consequences

• Barton on Sea

• Isle of Wight

• Holderness/Holbeck Hotel Scarborough

Issues relating to costs and benefits of scheme, including the potential for sustainable management

• Lyme Regis

Soft Engineering• Sefton Coast, North East England• Netherlands

Hard Engineering• Isle of Wight

Coastal flooding – physical and human causes and physical and socio-economic consequences

• Hurricane Katrina• Storm Surge 1953

Coastlines of Submergence• Dalmatian Coastline (Croatia)Coastline of Emergence• S.W. England Raised beach Portland Bill

Sea Level Change

• World sea levels have not remained constant over time

• The global water balance however, is fixed because it is a closed system

• The amount of water available to the oceans has fluctuated due to:– The amount of water locked up in ice caps– Tectonic changes affecting the rise and fall of

land masses

Sea Level Change

• Eustatic sea level change is caused by a change in the volume of water in the sea, or by a change in the shape of the ocean basins. The effects are always global.– Tectonic movements– Changes in climate

Sea Level Change

• Isostatic changes in sea level are caused by vertical movements of the land relative to the sea. The effects are always local.– Tectonic uplift or depression– Land subsidence after the extraction of

groundwater

What impacts can Sea Level Rise have?

1. More frequent and severe coastal flooding

2. Submergence of low lying lands3. Changes in coastline

(These changes can have further impacts e.g. damage to infrastructure, decrease in tourism, decrease in agriculture, loss of homes etc.)

Sea level rise results in coastlines of Submergence

• RIAS - drowned river valleys (gentle long and cross profile, wide and deep at their mouth, becoming narrower and shallower the further inland)

• FJORDS – drowned glacial valleys (straight and narrow, with very steep sides. They have a shallower mouth caused by a raised bit of ground – the threshold – formed by deposition of material by the glacier)

Dalmatian Coastline (Croatia)

• In areas where valleys lie parallel to the coast, an increase in sea level can cause flooding – the result of which are a series of islands located just offshore.

Sea level rise results in coastlines of Emergence

• Raised beaches• Relict Cliffs

These can be found at Portland Bill S. W. England. Vegetation and soil often develop on the wavecut platforms of raised beaches and on cliffs that were once submerged and under attack from the sea. THIS IS WHY THE RAISED BEACH AND PORTLAND BILL WAS HARD TO SPOT!

Using pages 106 – 108 in your AS text book

1. What does the term Isostatic seal levl change mean? (1 mark)

2. State 2 causes of eustatic sea level change. (2 marks)

3. Give 1 examples of landforms resulting from both types of sea level change. (2 marks)

4. Describe the possible impacts of sea level change (8 marks).

Practice Questions

1. Explain the meaning of the terms ‘abrasion’ and ‘corrosion’

2. Name 2 characteristics of a sediment cell (p85)

3. Draw and label the main features of a destructive wave (p84)

4. Name the 4 types of sub aerial weathering (p88/89)

5. What is mass movement? (p89)

Practice Questions

6. What are tides? (p86)7. What are spring and neap tides? (p85-87)8. What is the significance of:

a. The Swash zoneb. The Backshore zone? (p87)

9. How is a stack formed? (p92/93)10. What are sand dunes? (p97)11. What are the main characteristics of: a. Embryo dunes b. Grey dunes? (table 3.1 p97).

Practice Questions

12. How are salt marshes formed? (p98)

13. What is hard engineering? (p114)

14.Explain how two examples of hard engineering work (p114/115)

15.Give one disadvantage and one advantage of hard engineering. (p114/115)

16.Give one disadvantage and one advantage of soft engineering. (p115/116)

Practice Questions

17. What is managed retreat? (p116)18. Evaluate the coastal protection scheme

at Lyme Regis (15 marks) (118-124).

For this question, explain what has happened; consider the costs and disadvantages; the advantages; and write a personal evaluation (your opinion supported by the material above).

Practice Questions

19. What are the socio-economic causes of costal flooding in Holderness?

20. What were the cause of the 1953 storm surge?

21. How has the Isle of Wight protected itself from flooding?

22. Explain what has been done to protect the Sefton coast.