Coastal Environmental Change (Edexcel IGCSE Geography)

Influence of Geology

Spec point — 4GE1-S3.043

• Geology shapes the coastline over time, place and space

  • A coastline made up of softer rocks such as sands and clays will be easily eroded by destructive waves

    • They will form low, flat landscapes such as bays and beaches

  • Coastlines of more resistant, harder rock will take longer to erode

    • This will produce rugged landscapes such as headlands

• The differences between hard and soft rocks will also impact the shape and characteristics of cliffs

• Geology, therefore, shapes the coastline vertically through the height and profile of a cliff and horizontally with bays and headlands

Hard rock

• Hard rocks will lead to the formation of:

  • high, steep cliff shapes
  • bare and rugged cliff faces
  • boulders and rocks at the foot of the cliff

Soft rock

• Soft rocks lead to:

  • lower and more gently sloped cliffs
  • smoother cliff faces with evidence of slumping
  • few rocks at the foot of the cliff

Influence of Vegetation

Spec point — 4GE1-S3.043

• The longer a coastal landform has existed, the more likely it will be colonised by vegetation

• Over time, vegetation will 'fix' a feature (e.g. a sand dune)

• Vegetation adaptation is important to survive coastal conditions

  • Vegetation has to cope with high levels of salt in both air and soil

• The largest influence of vegetation is to assist in protecting and preserving coastal landforms such as sand dunes, salt marshes and mangroves

Influence of Sea-level Changes & People

Spec point — 4GE1-S3.043

• Sea levels have risen and fallen many times in the past

  • Rising sea levels produce submergent coastlines, with rias and fjords
  • Falling sea levels produce emergent coastlines, with relic features such as raised beaches, **cliffs with caves, arches, **etc.

• During the last** Ice Age**, sea levels fell as the water was locked up in glaciers and ice sheets, rising again as the ice melted

• Sea levels are linked to global warming and will have a significant effect on many low-lying coasts and islands

  • Many Pacific Ocean islands, such as Kiribati and Tuvalu are at risk of being completely submerged by rising sea levels
  • This issue is made worse as many of the world's densely populated areas are located on coastal lowlands
  • New York and Miami in the US are major cities vulnerable to sea-level rise as the cities are built at sea level

Influence of people

Human Activity

• Human activities, whether intentionally or not, transform the features and landscape of a coastline:

  • Settlement – coasts have always been a place of attraction and residence for people
  • Economic development - exploitation through fishing, farming, trade, tourism and energy production
  • Coastal management – controlling the coastline to protect human interests

• Through any or all of the above, the natural landscapes and features of the coast can be changed, thereby changing the coastline over time, space and place

Worked Example **Study Figure 2a in the Resource Booklet. Suggest two ways changes in sea level have created coastal landforms **

(4 marks)

• This question tells you to use the figure to show how changes in sea level have created coastal landforms
• You must identify features and then develop your answer to suggest how it was formed due to changes in sea levels
• If you do not refer to the figure, you will not gain full marks

Final answer: Answer:

• From the figure we can see where the sea level has decreased. [1] This has created an emergent coastline [1] with a relic cliff and raised beach**. [1]** Over time, the raised beach has become vegetated, supporting the observation of changing sea levels [1]

OR

• Wave action [1] from previous sea levels has eroded the relic cliff to expose a wave-cut notch [1], showing that sea levels used to be higher than the present. [1] This has led to the relic cliff and sea caves further back than the current cliff face in the figure. [1]