3-DIMENSIONAL NUMERICAL MODELING OF WIND-DRIVEN CIRCULATION IN A SHALLOW HOMOGENEOUS LAKE

The development, validation and application of a three-dimensional deterministic numerical model of the wind-induced circulation in a shallow homogeneous lake are described. The governing equations expressing the conservation of fluid mass and momentum are solved in the model using an implicit finite difference initial value method. Particular attention is paid to the representation of the bed friction, the wind shear stress and turbulent diffusion. The model was compared with analytical solutions for three idealised flows before being calibrated and verified with field data from Esthwaite Water in Cumbria. The model was tested for stability and parameter sensitivity and then used to generate typical circulation patterns for a variety of steady-state conditions. Comparisons with field measurements suggest that the model is better at predicting water movements in the open water than in the sheltered bays.