If 1930s seems like the worst drought we could ever have, scientific records show pre-settlement dry spells lasted far longer.
Likewise, there were wet spells on the Prairies much more intense than events like 2011’s — a flood we tended to call “unprecedented.”
Neither are unprecedented, say Saskatchewan scientists.
Both extremes have occurred before on the Canadian Prairies and will reoccur — and next time in a climate amplified by global warming, says Dave Sauchyn, a University of Regina professor of geography who shared findings of research done here to gather and study pre-settlement extreme weather events.
The keynote speaker at last week’s Assiniboine River Basin Initiative (ARBI) conference here, he described an analysis of ancient water level data gathered from tree rings samples collected across the Prairies and Northern Great Plains, including 1,000-year old Douglas firs along the eastern slopes of the Rockies and from 300- and 400-year-old burr oaks in the Assiniboine River Valley.
Tree rings show annual growth increments and are indicators of how much water the soil contained during the trees’ growth period, said Sauchyn, adding from their analysis they’ve been able to construct a very long record of weather events on the Prairies, including flows of the Assiniboine River right back to 1493.
What they see are periods of prolonged wet and dry periods exceeding anything experienced since Europeans arrived, he said.
As an example, the analysis shows years like 2011 have happened before.
“The trees capture that wet year of 2011. But if you look back to the early part of the record, there are two years that are equally wet,” he said. “It occurred at least twice in this 500-year record.”
The records are also indicators of intense droughts of yesteryear. For example, during a period in the mid-1700s the Assiniboine River at some junctures was little more than a trickle for at least a decade.
“We find periods of decades… 20 to 25 years… in which every year was dry,” he said. It was during one of these prolonged dry spells in the 1850s and 1860s, when Captain John Palliser came through this region to study its agricultural potential. What he reported was a region of desert-like conditions because he’d passed through here during one of those prolonged dry spells.
“He came through during a 20-year drought,” he said.
Where science makes things even more interesting is its predictive capacity too.
Sauchyn also described complex computer simulations that run hydrological and climate models together, and show how global warming could see extreme flooding in some parts of the basin beyond anything experienced to date.
“If we look into the future we can expect water levels unprecedented in terms of our experience with the basin,” he said. “So in other words, don’t be surprised if we get another 2011 or worse.”
In an interview Sauchyn commented that agriculture is “probably the most adaptive and resilient industry we have right now on the Prairies.”
But other conference speakers aren’t so sure, and said entirely new approaches to agriculture will be needed to face the future.
The much-altered Prairies are far less resilient than a century ago, said Michael Thiele, a Manitoba-based biological farm planning consultant, who described cropping practices that can help reverse soil organic matter and carbon losses, and enable soil to once again hold water. Soil sample records dating back to 1897 show soils in places like Yorkton and Salt Coats, Saskatchewan once had anywhere from 13 to 14 per cent organic matter but that’s not the case now, said Thiele.
“Those soils now on average are between two and four per cent organic matter. And soil isn’t holding water the way it used to. What we’ve done over a course of 100 years is we’ve turned soil into dirt.”
Other conference speakers such as Hank Venema, who is chief scientist with the International Institute for Sustainable Development (IISD) and director of planning for the Prairie Climate Centre (PCC) based in Winnipeg, spoke of the need to create a new class of infrastructure comprised of networked distributive storage systems across the Prairies. He also offered ideas on why investors will be interested to help pay for it.
“In a way it’s like the 21st-century analogue to the work PFRA did, but we’re going to bring a different level of networked engineering to the challenge,” he said.
Sauchyn, Thiele and Venema were among more than a dozen presenters during this fourth annual gathering of ARBI, founded in 2014 in Regina.
Other speakers described the soon-to-be unveiled Manitoba Forage and Grassland Association’s Aquanty hydrosphere model that will support decision-making and water management planning for floods and droughts ahead.
They brought in a lineup of these “timely, interesting and even controversial” messages as part of ARBI’s ongoing effort to support the decision makers in basin water management planning, said ARBI chair Allan Preston.
There were about 100 delegates attending the Regina conference held Feb. 14 and 15.
Preston said he’s confident ARBI continues to make progress. It operates by the adage ‘Rome wasn’t built in a day,’ he said.
“When we started out four years ago there was a degree of hesitancy about what this was all about,” he said. “Now I see almost unanimous support in the room for what we’re trying to do and what we’re trying to accomplish.”
The organization does struggle financially, however.
Preston said he was heartened last week by comments made by the Saskatchewan minister of environment at the gathering, and hopes a near-future meeting with Saskatchewan’s Water Security Agency may see some funding from the province follow.
In his opening remarks Dustin Duncan said “our government values the grassroots approach to water management represented by ARBI.”
“We appreciate that we have representatives from Manitoba, Saskatchewan and North Dakota at the table,” he said.
“It is great to see a high level of engagement in water management discussions across these borders.”