Mackenzie River basin
The Mackenzie River basin extends between 102–140◦ W and 52–69◦ N. It drains an area of about 1.775 × 106 km2 of western and northwestern Canada and covers parts of the provinces of Saskatchewan, Alberta, and British Colombia, as well as the Yukon and the Northwest Territories (NWT). The average annual discharge at the basin outlet to the Beaufort Sea exceeds 300 km3, which is the fifth largest discharge to the Arctic. Such a large discharge influences regional as well as global circulation patterns under the current climate, and it is expected to have implications for climate change.
Saskatchewan River basin
The Saskatchewan River Basin (SaskRB) encompasses portions of the Canadian provinces of Alberta, Saskatchewan, and Manitoba, as well as a small portion of the US state of Montana. The SaskRB is situated in western Canada (98° - 118° W and 48° – 56° N), with a total drainage area of 406,000 km2 and approximate maximum dimensions of 1300 km east-west and 700 km north-south. The source of the SaskRB originates in the eastern slopes of the Canadian Rockies in Alberta, which 25 includes parts of the Columbia Icefield. The two main tributaries of the SaskRB are the South and North Saskatchewan Rivers, both of which flow east and northeast through the Saskatchewan Prairies, before merging to form the Saskatchewan River, flowing through the Saskatchewan Delta (North America’s largest freshwater inland delta), and draining into Lake Winnipeg in Manitoba. The two tributary river systems are further subdivided into nine subbasins of the Bow, Red Deer, Battle, Upper North, Central North, Lower North, Upper South, Lower South, and Eastern Saskatchewan rivers. The Upper South basin can further be disaggregated into the Oldman basin and a small watershed draining from Montana, US.
The topographic elevation of the basin ranges between 218 and 3487 m above sea level. The physiographic characteristics extend from the rugged Canadian Rocky Mountains, foothills, and uplands on the far western side of the basin to lowlands and plains in the remaining parts of the basin. The Ecozones of the SaskRB are classified into four ecozones; Montane Cordillera, Prairie, Boreal Plain, and Boreal Shield, covering 6, 58, 33, and 3 % of the basin area respectively. The Montane Cordillera Ecozone encompasses all the rugged mountains of the basin, the Boreal Plain has gently rolling to level topography, and the Boreal Shield contains hilly terrain with numerous ponds, wetland, and lakes. The Prairie Ecozone covers post-glacial undulating plains to rolling plains and flat terrain with numerous depressional areas. The Prairie have several unique features: the pothole topography prevents some areas from draining to the major river system, the ecozone has internal drainage, and connection to the major river system are intermittent. The parts of the ecozone not draining to the major river system are commonly called “non-contributing areas”, defined as the drainage areas not playing a part in runoff in a flood that has a two-year return period.