Satellite images used to test lake water quality

With a little help from an eye in the sky, members of a local conservancy group recently began experimenting with a cutting-edge technique for measuring water quality on Rainy Lake.
Paul and Jesse Anderson, volunteers for the Rainy Lake Conservancy (RLC), were out on the lake Monday taking water samples and collecting data that will be correlated with overhead satellite shots.
If the venture is successful, the RLC could use the satellite images—taken daily—to keep close tabs on the water quality of the lake without ever leaving the shoreline.
The technique could be especially useful for monitoring spills, long-term septic tank leakage, or growing algae blooms.
“The idea would be to have a quick way, in real time, to evaluate the water quality of the lake,” Paul Anderson said Thursday morning from his cabin on Rainy Lake.
“We want to see if we can correlate satellite images with actual [data samples],” he explained.
Anderson said three key measurements—total phosphorus, chlorophyl levels, and the secchi disc reading (essentially how far you can see into the water)—need to be taken before the satellite imaging can be used.
He and his son, Jesse, collected that data from eight different spots on Rainy Lake earlier this week.
That information now is in the hands of scientists, Anderson said.
“The environmental scientists and image processors are going to correlate [the information collected] with satellite images taken on the same day,” he noted.
The Andersons will be making a presentation on the satellite sampling technique at the RLC’s annual general meeting this Sunday (Aug. 7) at 3 p.m. at La Place Rendez-Vous.
Everyone is invited to attend.
But the RLC is not the only group taking advantage of the new technology to better monitor the environment.
About 130 volunteers spent parts of the civic holiday long weekend taking water samples on Lake of the Woods and throughout northern Minnesota—part of a four-day effort co-ordinated by a handful of groups, including Minnesota Pollution Control.
The Andersons were the only volunteers out on Rainy Lake, but eight samples (taken from both sides of the border) should be plenty to start with, he said.
He added it’ll likely take a couple months for scientists to examine the satellite images and crunch the final numbers but, from what he observed Monday, the water quality on Rainy Lake appears to be pretty good.
“Not a problem,” he reported Thursday morning. “There’s always local issues, of course, but . . . in general, the lake is in pretty good shape.”
The RLC is a group devoted to preserving and protecting the Rainy Lake.