When we model the hydrologic system, we start in the groundwater system and work our way up. Our approach is to look at groundwater and surface water in a holistic manner, fully coupled.
Across Canada, groundwater makes up anywhere from 30% to 100% of the water that you see in rivers. A lot of the research effort and modelling efforts have thus far focused only on surface water. It's the water we see. But in times of drought, the water that flows in the rivers is groundwater that's discharging and that supports ecosystems. It supports waste-water assimilation. It supports irrigation demands. It supports municipal drinking water supplies.
So we start from the bottom up, look at the aquifers, look at the aquitards, the groundwater flow systems, and then we layer the land surface on top. That takes tremendous amounts of data. We have to characterize the subsurface digitally, and those data sets are not readily available. It's one of the big missing links in Canada. How do we characterize the subsurface so that we can incorporate it into models? We work very closely with the Geological Survey of Canada. They are one of the few federal organizations actually looking at the groundwater system. I think it fits into what they do in terms of skill sets and expertise, because when we're talking groundwater, we're talking hydrogeology. That's the world of earth system science. It ties into mineral exploration, geophysics and remote sensing.
A lot of the elements for building our models take data sets constructed by federal departments, including Geological Survey of Canada, Ag Canada, Canadian Space Agency and Environment Canada. We just consume data from all these different agencies, not from a single source but from wherever we can source it.