Numerical Modeling Study of Lake Pontchartrain

A Hansen-type hydronamical-numerical model is shown to adequately simulate actual wind circulation, water levels, and particulate matter dispersion in Lake Pontchartrain. The model is an explicit numerical difference scheme based on leap-frog integration through time of the two-dimensional Eulerian form of the hydrodynamical equations to obtain a dynamical boundary-valve solution of tidal order. The differential equations are derived by integration of both x and y velocity components through a layer of assumed uniform density to achieve vertically averaged mean components. Terms to account for rotation of the earth, wind and tidal forcing, and dissipative frictional effects are included. The diffusion and advection method used is a Monte Carlo stochastic process in which the model provides the advectional flow. Two simple applications demonstrate the ability of this model to accurately represent the movement of a lake surface under the influence of tides and wind. A third application demonstrates the ability to model the injection and plume dispersion of particulate matter in lakes.