physical landscape of uk

• Weathering


  The weakening or decay of rock due to the action of weather
• Types of weathering


  • Chemical
  • Mechanical
• Chemical weathering


  • Carbonation
  • Oxidation
  • Hydrolysis
• Mass movement


  The downslope movement of weathered material and rock under the influence of gravity
• Types of mass movement

  • Rockfall
  • Landslide
  • Mudflow
• Coastal erosion


  The wearing away of the landscape by the sea
• Processes of coastal erosion

  • Solution
  • Corrasion
  • Abrasion
  • Attrition
  • Hydraulic power
• Solution


  Dissolving of soluble chemicals in rock, e.g. limestone
• Corrasion


  Rock fragments picked up by the sea are thrown at the cliff, scraping and wearing away the rock
• Abrasion


  The 'sandpapering effect' of pebbles grinding over a rocky platform
• Attrition


  Rock fragments carried by the sea knock against each other becoming smaller/more rounded
• Hydraulic power


  The power of the waves as they hit a cliff, with trapped air forced into cracks in the rock eventually causing it to break up
• Ways sediment is transported

  • Solution
  • Suspension
  • Saltation
  • Traction
• Longshore drift


  The movement of sediment along the beach in a zigzag pattern due to the direction that waves approach the coast
• Deposition happens when water slows down and waves lose their energy
• Beaches are formed of sediment deposited in bays
• Mudflats and saltmarshes are often found in sheltered estuaries behind spits
• Factors influencing coastal landforms

  • Rock type
  • Geological structure
• Headland


  Tougher, resistant bands of rock are eroded more slowly to form headlands
• Bay


  Weaker rock erodes more easily to form bays
• Wave-cut platform formation


  1. Wave breaks against cliff, forming wave-cut notch

  2. Notch deepens, undercutting cliff

  3. Cliff collapses

  4. Sequence of notch formation and cliff collapse leads to cliff retreat and wave-cut platform
• Cave, arch and stack formation

  1. Large crack opens up by hydraulic action

  2. Crack grows into cave by hydraulic action and abrasion

  3. Cave breaks through headland, forming natural arch

  4. Arch is eroded and collapses, leaving tall rock stack

  5. Stack is eroded, forming stump
• Sandy beach


  Mainly found in sheltered bays, created by constructive waves
• Pebble beach


  Found along high-energy coasts, where sand is washed away
• Sand dune formation


  1. Embryo dunes form around obstacles

  2. Dunes develop and are stabilised by vegetation (e.g. marram grass) to form fore dunes and tall yellow dunes

  3. Decomposing vegetation makes sand more fertile and a wider range of plants colonise the back dunes

  4. Ponds (dune slacks) can form in depressions
• Spit


  A long finger of sand or shingle jutting out into the sea
• Bar


  Forms when longshore drift causes spits to grow across a bay
• Offshore bar


  Forms further out to sea where waves approaching a gently sloping coast deposit sediment (due to friction with the sea bed)
• Barrier beach


  Offshore bars driven onshore by rising sea levels
• Swanage lies on the south coast of England, with a range of coastal erosion and deposition landforms influenced by different rock types and geological structure
• Rocks have been folded and tilted so that different rock types reach the coast
• Swanage has a broad sandy beach and a sheltered bay
• Studland has extensive sand dunes and sandy beaches
• Headlands and bays are formed where there are alternating bands of harder (more resistant) and softer rock
• Marginal costs


  Costs that increase as production increases
• In some cases, increasing costs might outweigh the benefits in the future, so some courses of action could be inadvisable
• Coastal defences


  • They are used to protect people from erosion and flooding
  • They are expensive
• Hard engineering


  Uses artificial structures to control natural processes
• Soft engineering


  Involves methods that work with natural processes
• Managed retreat


  Controlled retreat of the coast (e.g. by allowing the sea to flood low-lying areas)