Hydrological Cycle Characteristics

• The hydrological cycle involves the continuous movement of water on, above, and below Earth's surface.

• It is a closed system with a fixed amount of water as water neither enters nor leaves Earth and its atmosphere.

• Water is stored in various places like land, sea, and atmosphere, and moves between them through flows or transfers.

Water Stores in the Hydrological Cycle

• Land Store

  • Water stored on the surface in rivers, lakes, and reservoirs.

  • Water taken in by plants and stored in vegetation.

  • Groundwater store in the bedrock.

• Sea Store

  • Over 95% of Earth's water is stored in the sea.

  • Water exists in liquid form and as ice.

• Atmosphere Store

  • Water exists as water vapor or droplets in clouds.

Changes in Water Stores

• The proportion of water held in different stores can change.

• Examples include conversion of liquid water into water vapor, precipitation, and transfer of water through soil and rock into groundwater store.

Water Transfers

Evaporation - Water is converted from a liquid to a gas. This takes place from the surface of the sea and other water surfaces and on land.

Transpiration - Plants take up liquid water from the soil and breathe it into the atmosphere as water vapor.

Evapotranspiration - The loss of moisture from the ground by direct evaporation from water bodies and the soil, plus transpiration from plants.

Condensation - The change in the atmosphere when water vapor cools and becomes a liquid. The liquid takes the form of water droplets that appear in the atmosphere as clouds.

Precipitation - The transfer of water in any form (rain, hail or snow) from the atmosphere to the land or sea surface.

Overland Flow - Most precipitation that hits the ground moves due to gravity and eventually enters a stream

Infiltration - The transfer of water downwards through the soil and rock into the aquifer (layer of permeable rocks) or groundwater store.

Groundwater Flow - This takes place between the ground surface and the top of the ground water store. As a result of gravity, water moves slowly through the soil until it reaches a stream or river.

Through Flow - This happens in the rocks of the aquifer and is the underground transfer of water to rivers, lakes and the sea.