ABSTRACT
Most scientists and engineers refer to MODFLOW [McDonald and Harbaugh, 1988; Harbaugh and McDonald, 1996; Harbaugh et al., 2000] as the computer program most widely used for constant-density groundwater flow problems. The success of MODFLOW is largely attributed to its thorough documentation, modular structure, which makes the program easy to modify and enhance, and the public availability of the software and source code. MODFLOW has been referred to as a “community model,” because of the large number of packages and utilities developed for the program [Hill et al., 2003]. In recent years, the MODFLOW code has been adapted to simulate variable-density groundwater flow. Because MODFLOW is so widely used, these variable-density versions of the code are rapidly gaining acceptance by the modeling community.
