The Canadian Great Lakes Basin is one of the largest freshwater reservoirs in the world and is a critical factor in Canada’s economy. However, like everything else, it is also threatened by the effects of the changing climate.
This motivated two UW researchers, Postdoctoral Fellow Jorge Andres Garcia Hernandez and Professor Roy Brouwer, to develop a model that relates changes in water availability with the economy. Their findings were posted in an article titled “A multiregional input–output optimization model to assess impacts of water supply disruptions under climate change on the Great Lakes economy” published in August 2020 on Economics Systems Research.
“We developed a model that tells the best possible allocation of water resources to economic activities in case of water supply reduction in the Great Lakes,” Hernandez said. “This water allocation takes into account the economic value of the different economic activities, as well as the trade flows among the regions that compose the Great Lakes.”
The model that they implemented involves creating different scenarios using the available data in order to evaluate how changes in the water supply may affect the economy.
“We gradually decrease water all the way to zero, as an extreme case just to see how the province responds,” Hernandez said.
There are many factors that may affect water availability in the Great Lakes.
“Using the Water Availability Index, the Great Lakes [are] already experiencing severe water stress [during the] month of August,” Hernandez said.
It is important to note that the water in the Great Lakes is considered non-renewable, or at the very least, renewable at a low rate.
Aside from the increasing demand and stagnant supply, there is also the threat of high levels of algal bloom. This is caused by rising precipitation rates, which increases nutrient runoff into the Lakes, producing algal blooms and contaminating the water.
Although it has not been implemented, this model has the potential to help governments with policy-making and further research. Their findings can act as the first step towards mitigating the potential effects of climate change on water basins.
“I think it would be useful in the design of sustainable water extraction policies,” Hernandez said.
The quantification of water reduction can assist in decision-making processes as it gives economic value, allowing further assessments to be conducted, such as the cost-benefit analysis.
“If we have the data, it could easily be translated to other regions,” Hernandez said.