The water cycle — Geography, 7–10 years
Water is always moving between the ground, the air and living things. The water cycle helps explain why rain falls, puddles vanish and rivers keep flowing.
Water keeps travelling
The water in a cloud may once have been in a sea, a plant or a puddle. Sunlight warms water so some changes into invisible vapour, which rises, cools and forms tiny drops. Those drops can fall as rain, snow or hail, then collect and begin the journey again.
Why does water return?
People needed to understand how a river could keep flowing even though water was always leaving it. The cycle shows that water does not simply disappear: it changes place and sometimes changes form. This helps us think about rain, droughts, floods and the water available for people and animals.
A puddle after rain
1. Rain leaves a puddle on a playground. 2. The Sun warms its surface, and some water becomes vapour that we cannot see. 3. The vapour rises and cools in the air. 4. It joins other tiny drops in a cloud. 5. Later, rain may return that water to the ground.
The water has not vanished
A puddle seems to vanish, so it is natural to say that the water is gone. In fact, much of it has become vapour and mixed with the air, where our eyes cannot see it. Some water may also soak into the soil or be taken up by plants, so not every drop follows the same path.
Water for a garden
Gardeners watch the water cycle when they decide whether plants need watering. After heavy rain, water may soak into the soil, run into drains or evaporate. During a dry spell, a gardener can water early or late, when less water is lost quickly to the warm air.
Keep exploring
Other languages
Loading MyLeoNes™…