The most important part of the modeling process, however, is that of conceptual modeling, of deciding how to represent a physical system with the model such that all the important features of a problem are adequately included. Properties can be spatially uniform throughout an aquifer or model layer, uniform within zones of nodes or elements, or unique for any or all nodes or elements. In all cases, the boundary conditions can vary in space and time. Special features include rising water table nodes which can be used to simulate streams, where the water table rises to the land surface, and excavations, where the land surface is lowered to meet the water table. The time integration method can vary between fully implicit and the Crank-Nicolson method.
Time steps can be constant or varying.
Iterative solutions can be controlled in several ways. Aquifer properties, boundary conditions and all other parameters for simulating both flow and transport can be assigned interactively. Maps can be saved in many formats or printed or plotted directly, with similar options to those for UniGraph. It provides support for PreAQ and AQPost, allowing the digitization of base maps prior to developing a grid with PreAQ, and enhancement of maps prepared with AQPost, i.e., by adding borders, title blocks and annotation. It can also be used as a stand-alone CAD or drawing package.