Documentation of computer programs to compute and display pathlines using results from the U.S. Geological Survey modular three-dimensional finite-difference ground-water flow model

Abstract

The illustration on the cover of this report shows the local, intermediate, and regional scale flow systems that develop in reponse to sinusoidal variations in water table elevation about an average linear regional gradient In this figure, a regional ground-water divide exists at the right boundary and the regional discharge area is in the upper left corner of the system. The analysis on which this illustration is based was originally done by Toth (1963) using analytical solutions for the ground-water flow equation. The cover illustration was generated by a particle tracking analysis based on a finite difference solution of case 2f in Toth's paper. The finite-difference solution used 100 cells in the vertical direction and 200 cells in the horizontal direction.