Ground-Water Management for the Nation’s Future—Computer Simulation of Ground-Water Basins

A mathematical model of a ground-water basin, representing its storage and transmissive characteristics, is developed and tested using general purpose analog and digital computers. The model permits water level elevations within the basin to be predicted, particularly in response to extraction and recharge activities carried out under a program of planned use and basin management. Large amounts of geologic and hydrologic data are collected, analyzed, and reduced for use in the computer simulate. A suitably simplified model of an aquifer system is developed that leads to the diffusion equation in two dimensions. This diffusion model is approximated by a system of difference-differential equations defined by a set of asymmetrically-spaced node points. The procedure developed for ground-water basin analysis is extended to handle certain nonlinear features.