Water cycle

Idea 1 Activity for reinforcing the idea of ‘The Water Cycle’ (4– 8 year olds)

Description

Children act out the different parts of the water cycle and demonstrate how they are connected.

When to use

1. Having established the general principle of the Water Cycle using available posters, books, drawings etc, this dynamic activity can be used to reinforce the idea that water particles are constantly being recycled.
2. Alternatively this could be a starting point for further exploration.

Equipment required:

Selection of musical instruments, enough for every child.
There must be enough instruments for 5 different groups each with a different instrument.

The Activity

In a large space, for example hall/playground, establish that each of the four corners is going to represent a different part of the Water Cycle: Sea, Sun, Clouds, Rivers. Alternatively make/draw a large circle and establish the 4 different ‘stations’ around the perimeter.
Divide the children into 5 groups and explain that 4 of the groups will represent each of the different ‘parts’ whilst the fifth will represent water particles/droplets and will move around the Water Cycle.
Ask each of the different groups to decide on an instrument which is appropriate to their part. E.g. rain sticks or similar to make the swishing sound of the sea, Indian bells for droplets etc.
Each group sit with instruments at their different stations whilst ‘droplets’ stand with theirs beside the ‘sea’.
Practise each group playing their instruments in turn whilst others listen carefully.
Then establish a means of ‘conducting’ the Water Cycle (a pupil could do this too)

The sequence should be as follows:

Sea
Droplets (move/play instruments in the sea)
Sun (providing heat to evaporate / free-up the droplets)
Droplets (move/play instruments from sea to sun)
Clouds
Droplets (move/play instruments from sun to clouds as they ‘condense’)
Clouds
Droplets (move/play instruments from clouds to rivers to represent rain)
Rivers
Droplets (move/play instruments from rivers back to sea)

Once the sequence is established, let each group have a turn at all the different parts (requires a certain degree of ‘management’ about putting instruments down and walking carefully to next ‘station’, one group at a time etc.)

Learning and Review

Finish the session with discussion about what the children have been learning and the ways in which they might understand the Water Cycle more clearly.
Terms such as evaporation etc can be discussed, with references made to puddles drying up - where has the water gone?
For cloud formation and rain, steam on bathroom mirrors is an easy one to explain (see Idea 2).

Idea 2 Two investigations to help understand key concepts about the Water Cycle

Description

Three investigations showing the three key processes involved in the Water Cycle – evaporation, condensation and water-flow (can be used at all stages of the Primary Curriculum)

When to Use

Having established the different stages of the Water Cycle (Ideas 1), it is useful to be able to demonstrate these in micro scale.

Evaporation/Condensation

Equipment needed

Salt, water, petri dish or saucer, small container for mixing, spoon, clear plastic drinks bottle with base cut off (can be ‘sharp’ so care to be taken when handling). Bottle should be large enough to fit over petri dish or area of saucer containing liquid.

The Activity

Introduce the activity – e.g. where does the water go? How does water leave the sea and turn into rain? Children will be able to come up with ideas in initial discussion which should direct them to an idea that they can represent evaporation of the sea by the sun, by warming up some salty water.
Ask the children to mix some salt and water in a container – 1/3 salt – 2/3 water is about right. Mix until salt is dissolved as much as possible and only make a small amount.
Depending on stage, ideas such as ‘fair testing’ etc can be introduced if comparing the results of different groups.
Pour the mixture into the petri dish or saucer and cover with the ‘cut off’ bottle (screw-top off).
Place somewhere warm and ideally near a window with direct sunlight and leave for a couple of days or until all the water has evaporated.

Review / Learning

Ask the children to predict what might happen.
When evaporation is completed, discuss formation of crystals and water droplets on bottle surface – evaporation and condensation.
Remind children that evaporation does not only happen from the sea, but from all bodies of water.
For older children you can set up two experiments alongside each other and compare results with the screw top left on (a closed / complete system - e.g. the World’s atmosphere) and off (an open system - e.g. a puddle that dries up as part of a larger eco system).

1. Condensation/Rainfall

Equipment needed

Kettle,water, mirror or window

The Activity

Discuss steam being formed when water is boiled (safety point about burns with steam).
Equate this to evaporation.
Boil kettle and hold mirror over steam or allow steam to reach a window.
The same coalescing effect can be achieved using a fine water spray on a window or mirror.

Review / Learning

Children observe what happens to water droplets as they coalesce when cooled down.
Lead discussion to equate this with condensation and cloud formation and eventually rainfall.

2. Rainfall/Rivers

Equipment needed

Plasticene, cotton wool etc.

The Activity

We need to understand that all water runs downhill and will eventually find its way into a river catchment and then back to the sea.
Ask the children to come up with ideas for proving this point. eg. by making different topographical models out of plasticene on top of which water is introduced.
It is also important to emphasise that water does not go directly into rivers but ‘seeps’ through the soil. (which can be illustrated by having a layer of cotton wool or piece of cloth on top of the plasticene.)

Review / Learning

Discuss the movement of water in relation to the part played in the Water Cycle.
Does all the water reach the sea straight away? Plants use some. We use some. Rainfall is added to by water waste produced from domestic, agricultural and business use.
Grasping these concepts allows the impact of water pollution to be better understood and addressed later.

Useful websites

Young People’s Trust for the Environment – very useful and pupil friendly source of information, easily searchable.
www.yptenc.org.uk search The Water Cycle

Scottish Water – information and activities
www.scottishwater.co.uk/education