Geography - Water, water everywhere
What it's all about
In the developing world, nearly 1 billion people are at the mercy of dirty, diseased water, but how do you convey this to children, writes Chris Fenton.
I explained to my Year 5 (P5) class that 97 per cent of the Earth's water is saline - I demonstrated using a large bowl and a clear 30cl water bottle. I poured 10 litres of water into the bowl (representing the world's total), then filled the 30cl bottle to represent all the fresh water in the world. Next I poured two-thirds of the water in the bottle into another container, representing unreachable fresh water.
The remaining one-third in the bottle is all we have to drink - for 7 billion people.
I split that into two glass jugs, one the drinking water of developing countries, the other for wealthier countries.
A lot of the water we drink comes from rivers, many contaminated with cholera, dysentery, typhoid and worm-based infections. So, why is the water in our tap so clean, I asked? The children were invited to make the water dirty, using soil, sand, dead insects and even raisins to represent poo, then dared to drink it. No one did.
I filtered one jug of dirty water through filter paper and a sieve and boiled it once it looked clear. One more sieve after it had cooled and it was clean enough to drink. In the other jug, the soil and sediments had sunk to the bottom, but food matter was dissolving and floating on the top. Which would the children rather drink? Millions of children don't have a choice.
Explore water issues using interactive resources from TESiboard. bit.lyiBoardWater.