Potential impact of climate change to the future climate and streamflow of the Mackenzie River Basin

  • Author / Creator
  • The Mackenzie River provides a critical corridor for Canada’s Arctic transportation network and the Mackenzie River Basin (MRB), the largest river basin of Canada, has been subjected to the impact of climate change. In this study, we have investigated the potential impacts of climate change on the MRB that could significantly alter the hydrology of the river basin. A regional climate model called WRF (Weather Research and Forecasting model) was set-up and fine-tuned to simulate the possible impact of climate change to MRB. WRF was sensitive with respect to parameters of the land surface scheme and micro physics options. Through a detailed fine tuning (calibration) process, by setting up WRF with the Noah Land Surface model, the Double Moment 6–class microphysics schemes, the CAM Shortwave and Longwave schemes, we found that WRF could generally simulate realistic climate over the MRB. The one-degree resolution, ERA-Interim data were used as input to WRF to simulate the regional climate of MRB which were validated against gridded observed climate data ANUSPLN of Environment Canada. The temperature and rainfall data that WRF dynamically down scaled from the ERA-Interim data as input generally compares well with the ANUSPLIN data, as well as some station climate data during the validation period (1979 to 1991). Next, using this model setup, future climate of MRB were simulated to assess the regional impact of climate change over the MRB. We used the CanESM2 global climate model (GCM) outputs at 275 km by 275 km (resolution) as the initial and boundary conditions to WRF model for simulating the climate of MRB for the base (1979 to 2005) as well as the future periods based on the CanESM2 RCP 4.5 and RCP 8.5 climate change scenarios over 2050s (2041 to 2070). The regional climate of MRB was simulated at 30 km x 30 km resolution every 6 hour for May, June, July, August, September and October (MJJASO) for each year. Comparing with the base period, the RCP 4.5 climate scenarios generally project a 2 to 4 ° C warming over MRB, particularly over the North and Western side of MRB, while the rainfall is projected to increase by about 75 mm for MJJASO over the MRB by 2050s. As expected, under RCP 8.5 climate scenarios, more pronounced warming is projected than RCP 4.5, with a 2 to 5o C rise in temperature in 2050s and the rainfall is projected to increase by about 85 mm over MJJASO and the spatial coverage of changes are projected to be larger than that of RCP 4.5 rainfall. Therefore, wetter and warmer climate are expected by 2050s from the WRF simulation for both RCP 4.5 and RCP 8.5 scenarios. Under the projected increase in air temperature and precipitation of RCP 4.5 climate change scenarios of the CanESM2 GCM of IPCC (2013) down scaled by WRF, the streamflow of the Mackenzie at the Fort Simpson and Arctic Red River stations are simulated using the conceptual hydrologic model HBV of Sweden. The streamflow for is projected to decrease mainly because more evaporation loss projected under a warmer climate is expected to offset the projected increase in summer precipitation over the MRB in 2050s. The projected decreased streamflow in could significantly affect the water resources and thus the navigability or northern transportation of the Mackenzie River in future.

  • Subjects / Keywords
  • Graduation date
    Fall 2016
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.