Visual Two Zone Model

The Visual Two-Zone Model (Visual TWZN) is freeware software to build up groundwater numerical modeling, in both radial and vertical flow components trough an abstraction well in layered aquifers. The conceptual model and computer native code was developed by Rushton and Redshaw (1979), Rathod and Rusthon (1984 and 1992), and the graphical user interface was developed by our Group Member, the hydrogeologist Noél Hernández Laloth.

The model, based on finite-difference approximations using the “two-zone” conceptual approach, can provide a greater flexibility than analytical methods, because the aquifer system is approximated as two horizontal permeable zones with less permeable intermediate layers. When this approximation is adopted, it is possible to represent both radial and vertical components of flow (Rathod and Rusthon, 1992). For this reason, the Visual TWZN is ideal of aquifer test interpretation using numerical methods.