Drilling deep for more accurate runoff

Reading Time: 2 minutes

Published: April 7, 2011

,

Five teams spread out across Saskatchewan last week for the first time in more than a decade to conduct snow surveys on farmland.

They are trying to determine the snow’s moisture content to better predict runoff.

“It’s been a while since it has been this high of a threat of runoff,” said John Fahlman, acting director of basin operations for the Saskatchewan Watershed Authority, while taking core samples near Martensville, Sask., March 29.

“We just go for a very short window (two days each) to try and match it with the satellite going overhead.”

Read Also

 clubroot

Going beyond “Resistant” on crop seed labels

Variety resistance is getting more specific on crop disease pathogens, but that information must be conveyed in a way that actually helps producers make rotation decisions.

Fahlman used a long bazooka looking instrument to take the samples in a procedure called ground truthing.

After taking six samples from a field, he weighed them and did the math to determine what the water equivalent would be in the snow pack.

Environment Canada will publish the information as a snow water equivalent contour map.

Moisture levels are mainly determined using satellite microwave images, but it is not a perfect system and at best provides moisture averages.

“Apparently with microwave you get a little bit of a melt and ice layers in the snow, which kind of knock them out,” he said.

“We try to ground truth it with data off the ground to say, ‘OK, it’s telling us there’s 80 millimetres of water here but actually we went and measured it and there’s only 50,’ or the other way around.”

Saskatchewan Agriculture also provides soil moisture conditions at freezeup.

“So our forecaster takes the base and then he adds this and all our other data sources from the microwave and snow pillows,” he said.

“It’s experience and judgment that takes it from that. Plus we have some statistical stuff that we do. OK, there’s going to be this much runoff, look at the statistics and then give it a frequency.”

The information is shared with officials who are responsible for dealing with high water levels.

This year’s information is indicating runoff will be high in many parts of the province.

“On the eastern side of the province, I’ve heard anecdotal evidence that they’ve (creeks and streams) been flowing all winter,” he said.

Fahlman said none of this information is new to most producers.

“Farmers know their own land. They know on a high runoff year where they have problems,” he said.

“All we’re going to do is we’re going to reaffirm to them that this is a big runoff coming. Where you’ve had problems in the past, get on it, is basically what we’re saying.… It also gives some legitimacy to the politicians, to the municipal governments: hey this is real. If you want to help them, get a program together and help them.”

About the author

William DeKay

William DeKay

explore

Stories from our other publications