A model for wetland surface water dynamics

A mathematical model for overland flow through vegetated areas has been developed. Input information includes site topography and porosities, power law parameters for the velocity correlation, and the driving forces: precipitation, evapotranspiration, stream flows, groundwater recharge or discharge, and pumped additions. Depths and flow rates are then calculated as functions of position and time. A one-dimensional algorithm has been developed to execute these calculations. Numerical solutions to the nonlinear partial differential equations are accomplished using special finite difference approximations. The method permits long simulation times (several years), without significant material balance errors. The model and simulator have been validated using data from the Porter Ranch peatland located near Houghton Lake, Michigan.