Systems and models

Systems approach

A term used to describe a method of simplifying and understanding a complicated set of interactions.

Reductionist approach

Involves dividing a system into its constituent parts and then studying them separately.

Holistic approach

Involves looking at all processes and interactions occurring within the system together, in order to study the system as a whole.

Transfer

A change in location

Transformation

A change in the chemical nature, a change in state or a change in energy

Storages are drawn as…

Boxes

Flows are drawn as…

Arrows

Open system

Both energy and matter are exchanged between the system and its surroundings

Closed system

Energy, but not matter, is exchanged between the system and its surroundings

Isolated system

Neither energy nor matter is exchanged between the system and its surroundings

Model

A simplified version of reality that is often used to represent a system

Model advantages

• Help understand complex system by simplifying them

• System inputs can be changed to observe outputs

• Results from models can warn us about future environmental impacts, and what we can do to minimise them

Model disadvantages

• Oversimplification of models can lead to inaccuracy

• Results from models depend on the accuracy of data that goes into them

• Results from models become more uncertain the further they predict into the future