Coasts as a System (AQA A Level Geography)

• A geographical system has inputs, stores, transfers and outputs
• The system constantly strives to be in a state of dynamic equilibrium
• The coast can be seen as both an open system and a closed system 
• It is an open system because it receives inputs from the lithosphere, atmosphere, hydrosphere, biosphere and cryosphere
• However, during research and coastline management the coast can be seen as a closed system where a specific sediment cell is examined

The coast as a system

• There are examples of positive feedback at the coast
• As waves erode the cliff, material is released
• This material abrades the cliff which results in even more cliff erosion 
• There are also examples of negative feedback at the coast 
• As the shore is eroded, material makes the wave cut platform wider
• This can absorb wave energy and reduce the impact at the base of the cliff

• Coastal systems are closely linked to other human and physical systems such as the atmospheric weather system or human agricultural systems 
• The climate system links very closely to the coastal system 
• During cold glacial periods global sea levels are much lower which affects the location of coastal landforms and processes 
• During the last ice age, low sea levels meant that the UK was connected to France by a land bridge that allowed early humans and animals to walk across
• Current changes in the global carbon cycle affect physical processes at the coast but also human ones as coastal regions are eroding faster and at greater risk of coastal flooding 
• Coastal systems are connected to other systems as they are part of the wider landscape. It is where the land mass meets the sea but there are other systems occurring at these locations too such as biotic systems or atmospheric systems 
• The coast has a number of distinctive landforms but many of these landforms are partly created by wind or rivers, showing again the connection between coasts and other natural systems 
• The picture shows the array of landforms that can be found at the coast but also how other geographical systems can interact and exist within coastal landscapes.

Interaction between the coast and other geographical systems