The technology exists to track build-up of groundwater. It’s a question of putting it to wider use
Water can be like buses − at one point you don’t think there’s enough, then it all comes at once. The change can come suddenly, as people in Calgary and southern Alberta discovered in the spring of 2013, when the Bow River flooded its banks and caused considerable devastation.
Often stricken by shortages and warnings to curb water use, the region was taken by surprise when the water came streaming through the streets of Calgary, High River and other communities. It doesn’t need to be as much of a surprise in the future, though. It’s becoming easier to predict these sudden onrushes of water, thanks to a pair of satellites operated by the Gravity Recovery and Climate Experiment (GRACE).
A joint mission of NASA and the German Aerospace Centre, the GRACE satellites, nicknamed Tom and Jerry, were launched in 2002. The satellites, which orbit 220 kilometres apart from each other, generate maps each month that measure the Earth’s gravity, showing detail 1,000 times more accurate than previous maps.
As the GRACE satellites go through their synchronized orbits, scientists monitor how tiny differences in the Earth’s gravitational pull affects their journey. The scientists can use this data to measure ocean circulation and changes in glaciers − and to weigh the volume of water stored in underground aquifers around the world.
By mapping underground water continuously, the scientists can detect buildup, which is exactly what happened in the western United States and Canada, including Alberta, last spring.
In June, Dr. Jay Famiglietti, a hydrologist at the University of California, Irvine, and a member of the GRACE science team, reported that there was data showing that groundwater was rising significantly in the northern U.S., especially around the upper Missouri River basin.
GRACE’s mapping in this instance did not include Canada, but it did show clearly that the increased groundwater trend extended north of the U.S. border and, by implication into Alberta. “It’s like a bucket filling up with water, it can only hold so much,” he said, during a conference on groundwater held at the University of Toronto.
The difficulty is that, prior to the Alberta floods, no one was analyzing what the U.S. GRACE maps might mean for southern Alberta. The flooding has brought more awareness of the tools available to predict future events, and the need to pay attention to groundwater pooling that we can now detect by satellite.
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This content was produced by The Globe and Mail's advertising department, in consultation with GE. The Globe's editorial department was not involved in its creation.
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