Visualizing water

The ecologist, Anthony Allan, of London King’s College has developed the concept of 'virtual water' for the total quantity of used to manufacture a product.

In brief, it is the quantity of clean water that evaporates, is consumed or is contaminated during the production of a product - from the watering of commodity crops to the water used to cool the machinery used.

When the 'water footprint' of various products is calculated, it reveals a much higher consumption of water than might have been thought at first sight.