SOLUTIONS TO WATER THREATS IN CANADA
Climate impact indicators
Global essential climate variables/indicators used
Precipitation and temperature from the HydroGFD2.0 dataset.
Global climate model (GCM) data (temperature and precipitation) from CMIP5 , for RCPs, 4.5 and 8.5, some available in the CDS catalogue.
Regional/local indicators used and produced
Streamflow and runoff
Global data to regional/local scale
Step 1: Bias correction of GCM data. CMIP5 GCMs data (precipitation and temperature) were bias-corrected using GFDv2 and the QQ mapping approach. Some models bias-corrected are available in the CDS catalogue.
Step 2: Downscaling of HydroGFD forcing. HydroGFD2.0 forcing data were downscaled using inverse distance weighting and IDW methodology to the resolution of the hydrologic model (i.e., HYPE, mean sub-basin size ~650 km2).Precipitation amounts were compared to those derived for HYPE from the original SMHI-derived Arctic-HYPE forcing, and other relevant Canadian datasets in the Nelson River basin (western Hudson Bay), where there is considerable disagreement among precipitation datasets.
Step 3: Calibration of HYPE hydrologic model. The hydrologic model was calibrated using HydroGFD2.0 forcing and streamflow and runoff were simulated for the entire historic period (1961-2015, model spin up from 1961-1979). Streamflow data (for calibration) from Dery et al. (2016) were observed, which presents a gap-filled, continuous dataset within the region of interest.
Step 4: Simulate streamflow and runoff. Streamflow and runoff were simulated using two future time periods (data from step1): 2030s (2021-2040) and 2050s (2041-2070). Changes in streamflow and runoff were evaluated for each time period, and for the entire period (2021-2070) relative to the simulated historic climate normal time period (1981-2010). Specific gauge locations of interest include major gauged outlets to Hudson Bay (Nelson and Churchill Rivers), and 16 control (regulation) points within the Nelson River basin.
Step 5: Compare HYPE simulations. Specific simulation metrics were compared to HYPE simulations driven by original SMHI-derived Arctic-HYPE forcing during both the historical and future projections to assess the relative impact, precipitation forcing data have on projections of future streamflow and runoff.