Coastal Systems

Systems in Physical Geography

Input

Material or energy moving into the system from outside

Output

Material or energy moving from the system to the outside

Energy

Power or driving force

Stores/ Components

The individual elements or parts of a system

Flows/ Transfers

The links or relationships between the components

Positive Feedback

Where a flow/ transfer leads to increase or growth

Negative Feedback

Where a flow/ transfer leads to a decrease or decline

Dynamic Equilibrium

The represents a state of balance within a constantly changing system. When the inputs and outputs are equal and balanced

Coastal Example:

Input

• Precipitation

• Wind

Coastal Example:

Output

• Ocean currents

• Rip tides

• Sediment transfer

• Evaporation

Coastal Example:

Energy

• Waves

• Wind

• Tides

Coastal Example:

Stores/ Components

• Beach

• Sand dunes

• Nearshore sediment

Coastal Example:

Flows/ Transfers

• Wind-blown sand

• Mass movement processes

• Longshore drift

Coastal Example:

Positive Feedback

• Dune erosion feedback loop

• Cliff erosion and slumping

Coastal Example:

Negative Feedback

• Formation of an offshore bar after a storm

• Wave-cut Platforms

Coastal Example:

Dynamic Equilibrium

• Beach rebuilding itself after a storm

• Seasonal beach profile changes between summer and winter