A global portrait of hydrological changes at the 2050 horizon for the province of Québec

Abstract

This paper presents the methodology and results of a vast study on climate change impacts on hydrology for the province of Québec for the 2050 horizon. A climate ensemble was first built with simulations from the World Climate Research Programme (WCRP)'s Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset, the North American Regional Climate Change Assessment Program (NARCCAP) and the Canadian Regional Climate Model (CRCM) operational runs. Direct outputs and post-processed data from the climate simulations were used as input to the calibrated HSAMI hydrological model in order to produce a large ensemble of hydrological projections for 305 Québec watersheds. Simulations results indicate that increases in mean annual streamflow are projected for the whole province, with greater changes (up to 14%) in the north. The intra-annual distribution of streamflow also changes, with higher winter flows and lower summer flows as well as apparently earlier spring floods. The maximum height of the snow cover and the number of days with snow on the ground are likely to diminish for the 2050 horizon for the southern half of the province, while the northern half will see more snow, but a shorter snow season as well.