JDB2D/3D consists of two fairly simple, easily modifiable computer programs for solving the two-dimensional, single-aquifer (JDB2D) and quasi-three-dimensional, multi-aquifer (JDB3D) formulation of the transient ground-water flow equation for confined and leaky-confined aquifer systems. The code is designed to run on a 16 bit computer in single precision, to be easily transferred between computer platforms, to be easy to use, and to be easily modified.

The governing equations are approximated using central finite differences for the spatial derivative together with a block-centered formulation. The finite difference equations are solved using the Strongly Implicit Procedure (SIP). The code solves the equations independent of units, allowing the user to specify any consistent units. The model requires a no-flow boundary around the area of computational interest, and source functions are used to approximate boundary conditions other than no-flow.

Input is developed by using a text editor (no preprocessor). Output files include text files with input data and results, and a file with locations and computed heads for graphic postprocessing. JDB2D/3D are two DOS-based executables running as a DOS application under MS Windows, distributed with source codes and example data sets.

SYSTEM REQUIREMENTS

Intel 80i86 based computer, 640 Kb RAM, DOS 3.1 or higher, CGA (no graphics included).

Developer: J.D. Bredehoeft (U.S. Geological Survey)