Natural water cycle

The natural water cycle is the continuous movement of water around the world through the processes of evaporation, transpiration, condensation, precipitation, run-off, infiltration and percolation.

Natural water cycle process


What happens in the natural water cycle?

The natural water cycle uses physical processes to move water from the surface of the Earth to the atmosphere and back again.

  • Evaporation is when the sun shines on water and heats it, turning it into gas called water vapour which rises into the air.
  • Transpiration is when the sun warms people, plants and animals and they release water vapour into the air.
  • Condensation is when the water vapour in the air cools and turns back into a liquid, forming tiny water droplets in the sky.
  • Precipitation is when water droplets fall from the sky as rain, snow or hail.
  • Run-off is when water flows over the ground and into creeks, rivers and oceans.
  • Infiltration is when water falls on the ground and soaks into the soil.
  • Percolation is when water seeps deeper into tiny spaces in the soil and rock.
Natural water cycle diagram

The natural water cycle moves water from the Earth to the atmosphere - and back again.

Water is continually moving through the natural water cycle.

Earth has exactly the same amount of water as it had thousands of years ago. This cycle is also called the hydrological cycle.

We modify and manage part of the natural water cycle to provide humans with water. This is called the urban water cycle.
 

Did you know?

  • Water is the most common substance found on Earth. It's the only substance found naturally in three forms – solid (as ice), liquid (as water) and gas (as water vapour).
  • Water is made up of tiny molecules. One water molecule, called H2O, is made up of three atoms - two hydrogen atoms and an oxygen atom. These atoms stick together due to electrical energy.
  • Water is a solvent, which means it dissolves things. Wherever it travels, water carries chemicals, minerals and nutrients with it. This means water is more than what we can see.
  • Water can be tested to see if it is acidic, basic or neutral. We like our water around neutral so it doesn't corrode pipes and home appliances.
Ph_scale_blue2

pH is measured in a scale from 1 (acid) to 14 (base) with 7 being neutral.

Did you know?
  • The total amount of water on Earth is 1,386 million km3
  • Water covers about three quarters of the Earth’s surface.
  • 96% of the world’s water is saltwater. 
  • 3% is of the world’s water is freshwater, but most of it is frozen or not easy to get.
  • Less than one per cent of the world’s fresh water is useable.
Have you ever wondered how water evaporates? Where clouds come from or where water goes after it rains? It’s all part of the water cycle.

Try these science experiments to see for yourself.
Terrarium with molecules, outline and sun

Create a mini Earth and water cycle.

Teacher resources

Primary School

School students

We have a range of online water education resources for primary school teachers and educators.

See all our online primary school resources.

High school

Students drinking water

We have a range of online water education resources for high school teachers and educators.

See all our online high school resources.