Effects of Climate Change on the Surface- Water Management of the South Saskatchewan River Basin

The Modified Interaction Soil Biosphere Atmosphere (MISBA) model, the Water Resources Management Model (WRMM) of Alberta Environment, and the Irrigation District Model (IDM) of Alberta Agriculture Food and Rural Development were used to assess the future outlook of water resource management of the South Saskatchewan River Basin (SSRB) of Alberta under the potential impacts of climate change. Using the SSRB hydrometeorological base data from 1928-1995, potential effects of climate change on the SSRB for 2010-2039, 2040-2069, and 2070-2099 were simulated by MISBA, IDM, and WRMM with the climate scenarios projected by four general circulation models forced by emissions reported by the Intergovernmental Panel on Climate Change. Under these climate projections, MISBA simulated a significant decrease in the mean annual average and mean annual maximum streamflows over selected nodes within the SSRB; the irrigation water demand projected by IDM is expected to increase progressively over the 21st century; and WRMM simulated changes to the number of deficit years out of 68years (1928-1995) to specific water sectors of the SSRB. Overall, according to the projections of WRMM, the instream flow requirement of SSRB will either not be affected or will only be marginally affected, but irrigation districts will be progressively affected by climate change. The senior private irrigation users will not be affected by climate change in 2010-2039 and will only be marginally affected in 2040-2069 and 2070-2099. In contrast, junior and future private irrigation users are projected to be progressively affected by climate change. On the other hand, for nonirrigation consumptive uses, all senior, junior, and future licenses may be significantly affected by climate change.