Application of a two-dimensional hydrodynamic reservoir model to Lake Erie

Abstract

The relative impacts of changes in nutrient loading and zebra mussel establishment on plankton in large lakes are strongly influenced by hydrodynamics, yet adequately modelling the temporal-spatial complexity of physical and biological processes has been difficult. We adapted a two-dimensional public domain model, CE-QUAL-W2, to test whether it could provide a hydrodynamically accurate simulation of the seasonal variation in the vertical-longitudinal thermal structure of Lake Erie. The physical forcing for the model is derived from surface meteorological buoys and measurements of precipitation, inflows, and outflows. To calibrate and validate the model, predictions were compared with an extensive set of field data collected during May through September 1994. The model accurately predicted water-level fluctuations without adjustment. However, significant modifications to the eddy coefficient turbulence algorithm were required to simulate acceptable longitudinal currents. The thermal structure was accurately predicted in all three basins, even though this laterally averaged model cannot simulate Coriolis effects. We are currently extending the model's water-quality module to include the effects of nutrient loading and zebra mussels on the plankton.