The MODAEM model is developed by Vic Kelson of Wittman Hydro Planning Associates in Bloomington, Indiana. Unlike finite difference and finite element models, analytic element models do not require a discretization of the problem domain. Rather the model is completely defined by boundary conditions, source/sink terms, and material property zones represented by points, polylines (arcs), and polygons. Since GMS users are already in the habit of building conceptual models in the Map Module using points, arcs, and polygons, analytic element modeling is a natural fit for GMS.