Coasts as Natural Systems

• The coast is an example of an open system. This means that it has inputs that originate from outside the system (such as sediment carried into the coastal zone by rivers) and outputs to other natural systems (such as eroded rock material transported offshore to the ocean).
• A really clear example of the application of systems concepts to the coast is the sediment cell. There are eleven major sediment cells in England and Wales, which form the basis for coastal management.
• Positive feedback

  Where a flow/ transfer leads to increase or growth

  E.g. Coastal management can inadvertently lead to an increase in erosion elsewhere along the coast.
• Negative feedback

  Where a flow/ transfer leads to decrease or decline

  When the rate of weathering and mass movement exceeds the rate of cliff-foot erosion a scree slope is formed. Over time, this apron of material extends up the cliff face protecting the cliff face from subaerial processes. This leads to a reduction in the effectiveness of weathering and mass movement.
• Backshore = area between the high water mark and the landward limit of marine activity
• Foreshore = between the high water mark and low water mark; most important zone for marine activity
• Inshore = area between the low water mark and where the waves cease to have any influence on the land beneath them
• Offshore = area beyond where waves cease to impact the seabed
• Landforms are created and shaped by a variety of natural processes, landscapes are made up of a variety of landforms