coastal management

• define hold the line - types of coastal management

  permanent structures
• define managed realignment - types of coastal management


  controlled erosion and flooding
• define no active intervention - types of coastal management


  happens in places...

  • less prone to erosion
  • with less economic value
• all management strategies claim to...

  • diffuse wave energy
  • reduce erosion
  • maintain sediment budget
• outline groins - hard engineering

  • rigid walls preventing long shore drift
  • creates a wider beach with shallow gradient
• outline rock armour - hard engineering

  • very resistant boulders piled up
  • usually made of granite or basalt
  • disperses wave energy
• outline sea wall - hard engineering

  • permanent barrier that is parallel to shore
  • usually made of concrete
  • curved surface = reflects wave energy back
• outline gabions - hard engineering

  metal cages filled with smaller rocks = disperses wave energy
• outline conservation - soft engineering

  • dune regeneration = marram grass or building a fence to prevent human damage
  • restoring salt marshes and wetlands = allows storm surge water to spread over a more controllable area
• outline beach nourishment - soft engineering

  • rainbowing and dredging offshore sediment = increases surface area of beach to diffuse wave energy
  • beach reprofiling = moving sediment from low to upper = creates a steeper beach = reduces swash
• outline cliff management - soft engineering

  to reduce risk of mass movement = slows erosion

  • cliff stabilisation = less permeable mesh layer
  • cliff drainage = long permeable tubes through sediment = excess precipitation can be removed from weaker sediment
• define extractive industries - economic activities unintentionally impact coasts

  primary industries that directly take materials from coastal areas for human use

  • oil / natural gas
  • fish farms
• outline oil / natural gas extraction - extractive activities

  most extractive and takes place offshore

  • option A: oil tanker transports product to port
  • option B: offshore oil / gas terminal = creates a physical barrier to sediment energy
• outline fish farming - extractive activities

  deforestation of intertidal mudflats to create space = vulnerable to erosion and potential increase in terrestrial sediment
• intentional impacts = coastal management

  unintentional = economic activities
• define commercial activities - economic activities unintentionally impact coasts

  • ports and harbours = fishing and recreational crafts
  • large scale, deep water ports
• outline ports and harbours - commercial activities

  • building on headlands = interrupts long shore drift = builds a new beach = slows erosion. But the area that the long shore drift sediement used to go to = loses sediment.
  • creating a small, flooded area on a river estuary = interrupts fluvial deposition and dredging = increases sediment
• outline large scale deep water ports - commercial activities

  • dredging channels to allow large ships in = deeper water = more wave energy = faster wave erosion = accelerates long shore drift = new landforms created faster.
  • extension of land towards sea = for property development. e.g. the Eco Atlantic, which is a new commercial and residential area built in Lagos, Nigeria