Natural System Components

• The coast is an open system as it receives inputs and transfers outputs away from the coast and into other systems. However, we should consider the coast as a closed system in some circumstances such as research and coastline management planning.
• Coasts can be split into sediment cells which are bordered by prominent headlands. Within these cells, sediment movement is almost contained and flows act in dynamic equilibrium.
• Inputs - may refer to material or energy inputs:

  • Marine: waves, tides, salt spray
  • Atmosphere: sun, air pressure, wind speed and direction
  • Humans: pollution, recreation, settlement, defences
• Outputs - may refer to material or energy outputs:

  • Ocean currents
  • Rip tides
  • Sediment transfer
  • Evaporation
• Stores/sinks - refer to stores and sinks of sediment and material. Formation of these stores discussed:

  • Beaches
  • Sand dunes
  • Spits
  • Bars and tombolos
  • Headlands and bays
  • Nearshore sediment
  • Cliffs
  • Wave-cut notches/platforms
  • Caves, arches, stacks, stumps
  • Salt marshes
  • Tidal flats
  • Offshore bands and bars
• Transfers/flows - processes that link the inputs, outputs and stores:

  • Aeolian processes
  • Mass-movement
  • Longshore drift
  • Weathering
  • Erosion
  • Transportation
  • Deposition
• Energy - power and driving force behind transfers and flows:

  • Wind
  • Gravitational
  • Flowing water