SICHUAN means 鈥渇our rivers鈥�,but the devastating earthquake in China鈥檚 Sichuan province, together with the powerful aftershocks down the , has dammed nine rivers and created 24 new lakes, which among other things pose renewed threats of landslides and floods.
When nature diverts waterways or creates lakes, no one can complain: its powers are often intractable, and when people make their homes on shorelines, mountains, known geological faults, or near volcanoes, they know they are taking a risk.
But when human activity is the cause of serious natural changes, as with plant and animal extinctions and the drying of rivers and lakes through overuse 鈥� think of the and the Aral Sea 鈥� we have only ourselves to blame. By the time it reaches the Dead Sea, the Jordan is now no more than a muddy streamlet; abandoned ships lie in a desert that was once the bed of the Aral Sea.
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鈥淎bandoned ships lie in a desert that was once the bed of the Aral Sea鈥�
We know the apparent paradox all too well: the surface of our planet is mainly water, yet usable water is in short supply. In some parts of Africa people have to walk several kilometres a day to get water, and they are the lucky ones. There, and in Asia, the prospect of conflicts over water is increasing.
A particular example is and its capital city, Ashgabat. Population increase and commensurate needs for increased agricultural output are the immediate prompts for this scheme. Turkmenistan is 80 per cent desert and relies on the 1100-kilometre-long Karakum canal to bring water from the Amu Darya river to Ashgabat and the cotton and wheat fields in the south.
The Karakum canal is the largest irrigation canal in the world and its water is the lifeblood of the country, providing 90 per cent of its supply. Without it Turkmenistan would be all desert, and practically uninhabitable. But the canal brings only enough water to make 4 per cent of the country arable; because the population has increased tenfold over the last century a new water solution has to be found.
The proposed answer is a new lake covering 3500 square kilometres, increasing the country鈥檚 arable land by 20 per cent. The problem, according to critics, is that such a big lake will further deplete the Amu Darya river, harming neighbouring countries. They argue it would be better for Turkmenistan to spend the money on relining the Karakum canal, which leaks half its contents into the desert. Turkmenistan鈥檚 government claims that the lake will be filled with run-off from existing agricultural land. Critics reply that keeping a lake filled in a desert, with unavoidable leakage into the sands, will require constant replenishment by massive amounts of water.
Turkmenistan鈥檚 exploitation of the Amu Darya is one of the principal reasons for the depletion of the Aral Sea. Once the fourth-largest lake in the world, the Aral is now the tenth largest, and it has become three times more saline than seawater. It no longer contains fish.
The north-west of neighbouring Uzbekistan has been hit hard by the Aral Sea disaster, and more-distant Kazakhstan is affected by the alkaline soil blown from the lake鈥檚 desertified bed. Such problems are progressive and cumulative: the soil-blow is causing increased respiratory illness and cancer in Kazakhstan, as it has already done in the Aral region.
All this illustrates the difficulty that water presents when shared and in short supply, as it will increasingly be in many parts of the world. I believe one thing is sure, however: this is a problem science can solve, though more resources are needed right now to make that happen before the water wars start.