Documentation of the Seawater Intrusion (Swi2) Package for Modflow

Download or read book Documentation of the Seawater Intrusion (Swi2) Package for Modflow written by Mark Bakker and published by CreateSpace. This book was released on 2014-06-23 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The SWI2 Package is the latest release of the Seawater Intrusion (SWI) Package for MODFLOW. The SWI2 Package allows three-dimensional vertically integrated variable-density groundwater flow and seawater intrusion in coastal multiaqui- fer systems to be simulated using MODFLOW-2005. Verti- cally integrated variable-density groundwater flow is based on the Dupuit approximation in which an aquifer is vertically dis- cretized into zones of differing densities, separated from each other by defined surfaces representing interfaces or density isosurfaces. The numerical approach used in the SWI2 Pack- age does not account for diffusion and dispersion and should not be used where these processes are important. The resulting differential equations are equivalent in form to the ground- water flow equation for uniform-density flow. The approach implemented in the SWI2 Package allows density effects to be incorporated into MODFLOW-2005 through the addition of pseudo-source terms to the groundwater flow equation without the need to solve a separate advective-dispersive transport equation. Vertical and horizontal movement of defined density surfaces is calculated separately using a combination of fluxes calculated through solution of the groundwater flow equation and a simple tip and toe tracking algorithm.