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Watch: The water cycle

Learn more about the water cycle in this 大象传媒 Teach video.

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What is the water cycle?

The Earth from space.

The water cycle works by using the energy of the Sun to exchange water from oceans and lakes to the atmosphere, and then back into the oceans again. It does this over and over in a continuous cycle.

What are the steps in the water cycle?

White fluffy clouds in a blue sky.
  • When the Sun shines, it warms water up and turns it into a gas - water vapour. This process is called evaporation.
  • The water vapour rises and collects in the sky as clouds.
White fluffy clouds in a blue sky.
Droplets of rain falling and splashing.
  • The water vapour cools down, condenses and turns back into a liquid. It then falls back to Earth as rain, snow, hail or sleet. These are all types of precipitation.
An aerial photograph of the River Usk in Newport, South Wales.
Image caption,
The River Usk in South Wales.
  • Soils absorb the water and rivers drain the water from the land. This water is called run off. The state of the soil and the type of vegetation influence how fast and heavy the run off is.
  • The water then flows back to the sea or lakes and the cycle starts again.
  • Water never leaves the Earth and its atmosphere. The water we use today has been around for as long as the Earth.
An aerial photograph of the River Usk in Newport, South Wales.
Image caption,
The River Usk in South Wales.
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What is groundwater flooding?

Flooding after heavy rain can cause a lot of damage to homes and businesses. When the ground is already heavy with rainwater, this makes it more difficult for the flooding to drain away.

River flooding might just last days but groundwater flooding can last for weeks or months.

Flooding over a road.
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Climate change and the water cycle

Flooding in a city. Cars are floating in water.
Image caption,
Flooding

Climate change is affecting the water cycle. As temperatures rise around the world, more water evaporates into the atmosphere. This is changing where rain falls and how much rain falls.

Flooding in a city. Cars are floating in water.
Image caption,
Flooding
Drought
Image caption,
Drought

The effects of climate change are not the same everywhere. Some areas may have heavier than expected rain and increased flooding, while others may experience drought. Some places may have both.

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Did you know?

  • A monsoon is a seasonal, wet and dry pattern of rain in tropical and sub-tropical regions, particularly in India and parts of South East Asia. Monsoons can involve floods and droughts.
  • Different types of clouds have names. Cumulonimbus clouds are the only type of clouds that can produce thunder, lightning and hailstones.
  • Kielder Water is the biggest reservoir (a human-made lake) in the UK. It is also home to England鈥檚 largest hydroelectric plant.
Kielder reservoir.
Image caption,
Kielder reservoir
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Watch: Lakes, lochs and reservoirs

Learn more about the lakes in this 大象传媒 Teach video.

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Activity: Quiz 鈥 The water cycle

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