Coastal Changes

• Influence of Geology

  • Geology shapes the coastline over time, place and space
  • Coastline made up of softer rocks such as sands and clays will be easily eroded by destructive waves to form low, flat landscapes such as bays and beaches
  • Coastlines of more resistant, harder rock will take longer to erode and produce rugged landscapes such as headlands
  • Differences between hard and soft rocks will also impact the shape and characteristics of cliffs
• Hard Rock

  • High and steep cliff shape
  • Bare rock and rugged cliff face
  • Boulders and rocks at foot of cliff
• Soft Rock

  • Generally lower and less steep cliff shape
  • Smoother cliff face with evidence of slumping
  • Few rocks, some sand and mud at foot of cliff
• Geology shapes the coastline vertically through the height and profile of a cliff and horizontally with bays and headlands
• Influence of Vegetation

  • 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 in order 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
• Submergent coastlines

  Produced by rising sea levels, with rias and fjords
• Emergent coastlines

  Produced by falling sea levels, with relic features such as raised beaches, cliffs with caves, arches etc.
• Sea levels have risen and fallen many times in the past, with the last Ice Age seeing sea levels fall as 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, with Pacific Ocean islands such as Kiribati and Tuvalu at risk of being completely submerged
• Many of the world's densely populated areas are located on coastal lowlands, making major cities like New York and Miami vulnerable to sea-level rise
• Influence of People

  • Human activities, either intentionally or not, transform the features and landscape of a coastline through settlement, economic development, and coastal management
• 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