ALN No. 45: Allan: Water Stress and Global Mitigation: Water, Food and Trade

ALN #45, Spring/Summer 1999 Water in Cities Water Stress and Global Mitigation: Water, Food and Trade by J. Anthony Allan "The impact of drought is very different on a diverse and strong political economy than on a weak political economy. It is essential that those devising remedies to drought events take into account political and economic futures different from those that exist now. The future w

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"Virtual water" represents the amount of water needed to raise a certain quantity of food. In other words, a tonne of grain has 1 tonne of "virtual water" embedded in it because that is how much water it took to raise that amount of grain. The concept of "virtual water" is powerful in two senses. First it provides the remedy for progressive and occasional local "agricultural" drought. Agricultural drought is the form of drought which is most common as deficiencies in soil water are evident in the failure of crops. The much smaller quantities of water needed for domestic use almost always come from other parts of the hydrological cycle than the soil water which supports crops.