Winnipeg, MB (May 13, 2020) - A recent Manitoba Agriculture Resource Development Innovation and Research stream-funded modelling project under the Canadian Agricultural Partnership and led by Manitoba Forage and Grassland Association (MFGA) is clearly showing that when climatic events flip quickly from very wet to very dry in back to back years that regions with healthy soils, grasslands and wetlands are much better-positioned to deal with the negative impacts to the system.
Investigating the influences of soil health and landscape management on the hydrologic behavior of the Assiniboine River Basin (ARB): Oak River/Shoal Lake - HydroGeoSphere Modelling Study, was recently web-presented by project lead scientist Dr. Steven Frey from Aquanty Inc., Waterloo, Ont. to a technical group of stakeholders from agriculture, government and conservation interests. The Project is also supported by the Assiniboine West Watershed District (AWWD) and utilized the MFGA Aquanty HydroGeoSphere Model for the Assiniboine River Basin - constructed via Growing Forward 2 project funding to look at the role of forages and grasslands in times of flood or drought across the Assiniboine River Basin - to run climatic scenarios in the Oak River Watershed in west-central Manitoba. The model scenarios clearly showcase that in years that shift from very wet to very dry that these landscape characteristics are even more valuable to the Agro-Manitoba landscape than what many assume.
"Producers, land managers and conservation professionals who work on agricultural-based lands will tell you that healthy soils, grasslands and wetlands - vital components of livestock production and conservation focuses - are valuable forces in buffering the impacts of flood and retaining water supplies during drought," says Larry Wegner, MFGA Chair. "As producers, we manage our lands and we know our lands. However this information from the Oak River scenario clearly shows the power of soil, grasslands and wetlands as they interact with the natural groundwater system in order to buffer flood and drought impacts in back to back years. And that is something many Manitobans should be aware of. It's a natural water management system that Manitobans directly benefit from."
The MFGA Aquanty's Oak River scenario project came to reality via the Canadian Agricultural Partnership (CAP), Manitoba Agriculture Resource Development department's funding up to $60,400 of the project while Aquanty, MFGA and the AWWD teamed up on the necessary project match and in-kind work of approximately $65,000 to help make it happen. The project provided a detailed assessment of the 2000 sq-km Oak River watershed, which includes Shoal Lake and the Shoal Lake catchment area, conducted with a HydroGeoSphere fully-integrated groundwater - surface water model in order to evaluate watershed sensitivity to physical and climate characteristics. Model scenarios were designed to test the sensitivity of watershed behavior to soil permeability, wetland/depression water storage, agricultural field microtopography, and precipitation and evapotranspiration variability. It was here where the water infiltration abilities of healthy soils, the slowing of water by grasslands and the healthy soils below them, and the water storage and water-slowing abilities of wetlands really shone.
"The sensitivity analysis was conducted for the 2009-2015 time interval which includes the 2011 and 2014 floods, as well as a number of drier years, such that the influence of landscape factors can be assessed for both wet and dry conditions," says Frey. "The unique ability of the HydroGeoSphere modelling approach to emulate the dynamic interplay between the land surface, soil, and groundwater systems is proving crucial for addressing questions pertaining to sustainable water resources management in this hydrologically complex region."
Coming out of the project, MFGA will be working to inform as many key stakeholders as possible about the Oak River scenarios and the ability for the model to do similar in other regions and watersheds around the Assiniboine River Basin. Ryan Canart, AWWD manager, says the Oak River information will become a key focus in the extension and outreach materials of the district as well as a key planning tool for on-farm, retention and restoration projects in the future. He feels the model can help target limited resource management dollars at the most cost effective activities.
"Assiniboine West Watershed District believes that the HGS model will help in the long-term planning and management of the water resources of the watershed," says Canart. "In this complex and multi-jurisdictional watershed, the ability to model various water management strategies helps save time and resources. The model gives us the ability to test various practices and management scenarios and inform the broader stakeholder group on how the watershed responds to the various scenarios."
Frey still has final tweaks on the model and will be focusing his attention on academic papers and further presentations to key audiences. He believes the MFGA Aquanty Model and the Oak River scenarios as well as 2018-completed scenarios on the Scallion and Birdtail Creek clearly signal the importance of soils, grasslands and wetlands in water management, community resiliency and producer engagement.
"This work is exciting in that it is providing a bridge between state-of-the-art science and on-the-ground practices in order to help guide us towards an agricultural landscape that is optimized for climate resiliency," says Frey.
