This water cycle has 4 key processes which help to move water and transform it into different forms: evaporation, condensation, transpiration and precipitation.
When the sun shines on the sea it causes water to evaporate and rise into the air to form water vapour. As this water vapour cools it may fall again, as rain, hail or snow. Some of this precipitation will evaporate once more and return to the sky, some will soak into the ground or be transpired by plants and eventually flow into rivers, streams, lakes, wetlands or the ocean.
What you will need
- A large clear glass bowl or ice-cream container
- A mug
- Cling wrap
- Small weight (rock or stone)
- Food colouring
- The Water Cycle poster
- Put warm water into the bottom of a large glass bowl or ice-cream container. Food colouring can be added for extra effect.
- Place a dry cup or mug in the centre of the bowl.
- Cover the top of the bowl with cling wrap so there are no gaps, don’t pull it too tightly.
- Place a small weight in the centre of the cling wrap so the film sags in the middle.
- Place the bowl in direct sunlight and leave it for a few hours.
The sun will heat the water in the bowl causing it to evaporate into water vapour. This will then rise hitting the cling wrap and cool (condensing) forming water droplets. The droplets will continue to collect on the cling wrap until they become too heavy, when they will drip down and fall into the mug. The weight is to provide a sloping surface for the water to drip from and guide it into the mug.