Changing contribution of snow to Hudson Bay river discharge

Hudson Bay (HB) in northern Canada has experienced changing volumes and seasonality of streamflows in the last 100 years. These shifts may be due to changing snow accumulation and ablation regimes. This study quantifies the changing contribution of snow to river discharge from 20 major river basins draining into HB (including James Bay) between 1980 and 2013. The analysis is based on daily snow water equivalent (SWE) data from GlobSnow, and daily streamflow data from the Water Survey of Canada, Hydro-Qu~bec, and Le Centre d\u2019Expertise Hydrique du Qu~bec. The contribution of snowmelt to streamflow generation is estimated from the ratio of water year maximum SWE to runoff. The Mann-Kendall test is performed for evaluation of trends and their significance. In HB, the snowmelt contribution to streamflow generation during 1980 to 2013 decreased by 15.9% (34 yr)\u207b~ and changed in hydrological conditions are observed. The potential impacts of these changes on ecological and socio-economic systems across much of Canada\u2019s North are discussed.