Three-dimensional mesh resolution control in finite difference groundwater flow models through boxed spatial zooming

SummaryThe iterative composite mesh simulation (CMS) technique operates a coupled system of point centered finite difference groundwater flow models. It allows for high lateral and vertical mesh resolution at the sites of interest, whereas a coarser mesh may be applied in other parts of the formation. The boxed spatial zooming method utilizes a “box-in-box” architecture to build the coupled 3D system of embedded (nested) parent and child meshes exhibiting different vertical and lateral extensions and resolutions. A mesh interface simulator is used to equate the heads and balance the fluxes along the common vertical plains and shared lateral layers (interfaces) linking the meshes. This multi mesh simulation method is used by software FLOW and has been successfully tested in multi-aquifer systems against selected unsteady and steady state well flow problems with available analytical solutions. The base compatibility with MODFLOW databases supports wider use of the FLOW simulator.