I must say The word from on high: we’re drying up fast impressed me when I read about it this morning.
SATELLITES have been used to map all of Australia’s fresh water for the first time, and the picture is bleak. In just three years, the continent has suffered a net loss of 46 cubic kilometres of fresh water – enough to fill Sydney Harbour more than 90 times.
Initial results of an extraordinary international satellite project provide yet another indication that Australia is drying out.
Based on current consumption patterns of about 1.5 billion litres a day, the water lost could have quenched Sydney’s thirst for more than 80 years.
The discovery has been made using two US and German satellites designed to map all the world’s water stocks – a task never before possible.
Launched by a Russian rocket in 2002, GRACE, the Gravity Recovery and Climate Experiment, involves two identical craft circling 220 kilometres apart, 485 kilometres up. By repeatedly plotting variations in the tug of earth’s gravity, GRACE can estimate changes in the mass of the water below. “Even water in aquifers,” said Jay Famiglietti, a hydrologist at the University of California, Irvine. It also measures water in river basins and reservoirs.
That is alarming news, too, though there is insufficient long-term data from this source for any confident extrapolations to be made from it, and it is obvious that causes are not addressed either. But what a neat application of science!