System Components and Dynamics

Front

Where matter or energy is added to the system

Back

Inputs in a system

Front

Limits to the system (e.g., watershed)

Back

Boundaries in a system

Front

When inputs equal outputs despite changing conditions

Back

Dynamic equilibrium

Front

Water stored in the soil, utilized by plants. Mid-term.

Back

Soil Water

Front

Water stored in a river. Short-term.

Back

River Channel

Front

Used to express water storage and transfer in a drainage basin system. Explains droughts or floods.

Back

Importance of Water Balance

Front

Dependent on physical factors, especially seasonal variations of temperature and precipitation.

Back

Factors Affecting Water Balance

Front

Precipitation: 150mm, Runoff: 50mm, Evapotranspiration: 10mm, Change in storage: +90mm.

Back

Winter Water Balance Example

Front

Ploughing increases infiltration, drainage ditches increase surface runoff and streamflow.

Back

Arable farming impact on water cycle

Front

Increases surface water storage, decreases runoff.

Back

Hillside terracing effect on water cycle