Numerical simulation of the influence of a Red River flood on circulation and contaminant dispersion in Lake Winnipeg

The Red River valley experienced one of the worst floods in 1997 because of above average snow accumulation, a blizzard during the snowmelt period and high soil moisture conditions. A three-dimensional hydrodynamic modeling system is used to study the impact of the flood on the circulation and contaminant dispersion in Lake Winnipeg. To assess the model performance, we first simulate the circulation and temperature distribution of the lake in 2007 and compare the model results with the observations made in the lake during this period. The model showed considerable skill in reproducing the thermal structure, currents and water levels. The accuracy of these simulations suggests that the model is capable of describing flow and transport of material required for detailed water quality simulations during the flood. During the flood event, Red River plume movement is primarily controlled by the wind-driven currents. The winds from the north confined the plume to a small area near the river mouth.