The Water Cycle (Cambridge (CIE) IGCSE Environmental Management): Revision Note

Water is constantly recycled through the water cycle

The water cycle includes stores and transfers

Stores are those places where water is held for a period of time

Stores of the water cycle include:

• The atmosphere where water is stored in the form of water vapour or as water droplets in clouds

• Surface stores such as puddles, lakes, rivers and reservoirs

• Aquifers, which are permeable rocks such as limestone and sandstone which can hold water (known as groundwater)

• Ice and snow (including ice sheets and glaciers)

• Seas and oceans (salt water)

Transfers are how water is moved around the water cycle

Transfers include:

• Precipitation is the transfer of water from the atmosphere to the Earth's surface in the form of hail, sleet, rain or snow

• Interception is how precipitation is prevented from reaching the ground, usually by being caught on leaves or branches

  • Some of the water will be stored on the leaves and evaporate into the atmosphere

  • The remaining water will flow down the leaves, branches and trunk until it reaches the ground (stemflow)

• Surface run-off (also known as overland flow) is any water flowing across the Earth's surface

• Infiltration is when water is transferred from the surface into the soil

• Throughflow occurs when water is transferred through the soil between the surface and the water table

• Groundwater flow is the transfer of water through rocks

• Transpiration occurs when plants release water vapour from their leaves

  • This process transfers water from the plants into the atmosphere

• Evaporation is the change of water from a liquid to a gas (water vapour) due to heat from the sun

  • This process transfers water from the surface up into the atmosphere

  • Higher temperatures and strong winds lead to increased evaporation

• Condensation occurs when water cools and changes from water vapour into a liquid (water droplets)

  • Condensation leads to the formation of clouds