In the Northern Hemisphere, climate change projections indicate that Arctic and subarctic regions will show larger changes in the variability and intensity of the climate conditions than most regions of the world. Global estimations have shown that Arctic basins will experience spring flow enlargements due to significant increases in precipitation and snowmelt. Previous studies have identified these changes in discharge patterns as one of the main drivers in future river thermal regimes. However, studying the arctic rivers is challenging given the problems related to data gathering. In this study, we use CEQUEAU, a coupled water temperature-hydrological model to simulate the present and future water temperature regimes in the Mélèzes river, a subarctic basin located in the northern region of Quebec. We forced the CEQUEAU model with reanalysis information from ERA5, and we used water temperature data derived from Thermal Infrared (TIR) images from Landsat as reference information. Given the distributed mapping capabilities of the TIR images, a multi-site calibration strategy was designed to calibrate the water temperature module in the CEQUEAU model. The results show that the multi-site calibration outperforms the single-site calibration in the studied river. Landsat showed to be a good source of water temperature information, and in combination with the CEQUEAU model, we were able to generate consistent daily water temperature time series distributed on the basin. These results will allow us to generate future scenarios of potential changes in the location of thermal refugia for key cold-water fish species under climate change conditions in Northern Quebec.
