Geohydrology and hydrogeochemistry of groundwater : streamflow systems in the Wilson Creek Experimental Watershed, Manitoba

Abstract

Geohydrologic and hydrogeochemical investigations of groundwater-streamflow systems in Wilson Creek watershed made possible further development and refinement of the hydrochemical method of hydrograph separation. During storm runoff periods, dilution behaviour of the major ions in the streamflow is dependent upon its concentration in each of the streamflow sources, direct runoff, channel precipitation, quick return flow and extended return flow. The ions chosen to charactersize a particular component or group of hydrograph components relate closely to the physical system as described. Groundwater flow patterns and hydrochemistry indicate that during periods with little or no precipitation streamflow is maintained by extended return flows discharging from local and intermediate, transverse flow systems principally in dissected reaches of the watershed. High hydraulic conductivity of the Riding Mountian formation coupled with large transient water table fluctuations during storm runoff periods result in increased extended return flow contribution to the streamflow.