Topic 5: The Water Cycle and Water Insecurity - The Hydrological Cycle

Vocabulary flashcards covering the key terms, processes, definitions, and components of the hydrological cycle and global water budget.

Hydrological Cycle

A closed system driven by solar energy and gravitational potential energy, where water is continuously cycled between different stores without external inputs or outputs.

Stores

Locations within a system where matter or energy builds up, which can be temporary or long-term.

Flows

Movements of matter or energy between stores; also known as transfers.

Inputs

Occurrences when matter or energy are added to a system.

Outputs

Occurrences when matter or energy leave a system.

Solar Energy

The source of heat that moves water from the surface of the Earth, oceans, lakes, and rivers to the atmosphere via evaporation.

Gravitational Potential Energy

The force that causes water to flow downhill, both on the surface and through soil, and causes precipitation to fall from the sky.

Hydrosphere

The system including all of the water on Earth, containing $1.4$ sextillion litres of water.

Blue Water

The rainwater that enters rivers, lakes, and groundwater.

Global Water Budget

An accounting of all the water in the whole hydrological cycle, tracking how much water is held in different stores and flows and how long it stays there.

Residence Time

The average length of time a water molecule spends in a given store.

Non-Renewable Water

Water that is not replenished for a very long time due to its residence time, such as water stored in the cryosphere or deep groundwater in fossil water.

Fossil Water

Ancient, undisturbed bodies of water trapped underground.