Groundwater storage – streamflow relations during winter in a subarctic wetland, Saskatchewan

Abstract

Wetland drainage systems are shown to be hydrologically active during winter. Water storage in various terrain types changed over the winter as a result of intrabasin transfers between terrain types, primarily from outlying mineral terrains to centrally located groundwater controlled wetlands, and due to winter streamflow. Mineral terrain and bog lost 97 and 25 mm of water, respectively, whereas fens gained 28–51 mm. A water balance indicated that mineral terrain yielded almost twice as much water as was released as streamflow, and that much of this excess was being stored in the fens where groundwater seepage at the surface resulted in icings. Bogs had little ability to sustain winter streamflow. Diminishing streamflow in early winter coincided with freezing of the surface layers of peat, which normally transmit most of the water. However, streamflow was maintained throughout winter by water transmitted through the fens.