Waterloo Hydrogeologic is pleased to announce the release of Visual MODFLOW Flex 2014.1 which provides support for MODFLOW-USG – a new finite volume version of the MODFLOW groundwater flow program that uses flexible and efficient unstructured grids to deliver increased accuracy and reduced simulation runtimes.
Visual MODFLOW Flex 2014.1 is unique in that it permits users to define unstructured grids composed of polygons of varying sizes. Polygonal grids naturally conform to the variation of the surface and subsurface layers resulting in a more accurate representation of the groundwater flow system and complex geologic formations. While the superior advantages provided by polygonal grids have been recognized in other modeling applications for many years, support for this grid type in Visual MODFLOW Flex represents the first instance ever for any commercial groundwater modeling application.
Unlike previous versions of MODFLOW, MODFLOW-USG permits localized grid refinement along model features such as rivers and around wells, as well as discontinuous layering. These new capabilities deliver increased resolution and accuracy in the areas of interest with much fewer grid cells. The use of polygonal grids also means that ghost-node correction is not necessary, avoiding potential numerical instabilities that may be associated with this correction. As a result, unstructured grids are faster, more efficient and more dependable than traditional MODFLOW grids. Early benchmark tests that compare the performance of MODFLOW-USG to MODFLOW-2005 using Visual MODFLOW Flex demonstrate a 96% reduction in simulation run times.
Visual MODFLOW Flex provides an intuitive user interface for building, running and visualizing MODFLOW-USG models. Unstructured grids are automatically generated from the 3D geologic model, and numerical model inputs such as boundaries and properties are automatically populated from conceptual data. High resolution renderings of model results can be visualized and interpreted in 2D and 3D viewers, and exported to standard image formats for inclusion in reports and presentations.