Breakup of small rivers in the subarctic

Abstract

At the end of the winter, the channels of small, subarctic rivers in the coastal James Bay Lowland are filled with snow, river ice, and icing. The major processes associated with the breakup of these rivers include the melting of the snow cover and the resultant generation of meltwater, the impoundment of meltwater runoff by snow dams, the disintegration and ablation of the river ice cover, the formation and dissipation of ice jams, and an exchange of overland and channelled flow between the rivers and their adjacent wetlands. A generalization of the breakup sequences allows a qualitative prediction of the events for specific segments of the channel. Findings of this study are applicable to the many small, subarctic rivers that fringe the James Bay and Hudson Bay coasts.