A toolset for handling unstructured voronoi grids for MODFLOW

MODFLOW is a modular hydrologic model developed by the United States Geological Service since 1984. The last version, MODFLOW 6, allows the use of finite volume (FV) general unstructured grid approach to solve the groundwater flow equations. The FV method entails constraints that are implicitly satisfied by a Voronoi dis-cretization. In this paper, new versions of the freeware VORO2MESH and TOUGH2Viewer tools are presented for Voronoi grid generation for MODFLOW. Originally developed for the TOUGH family of codes, both software has been improved to also work with MODFLOW. VORO2MESH and TOUGH2Viewer have been applied to two case studies and the results have been compared with analytical solutions. Outcomes have demonstrated that VOR-O2MESH grids give simulation results very close to locally refined Grids created using the Quadtree approach; furthermore, the simulation activities are substantially enhanced using TOUGH2Viewer.

Automated summary

This paper presents new versions of VORO2MESH and TOUGH2Viewer software for generating Voronoi grids for MODFLOW. Two case studies have been conducted and compared with analytical solutions. The results show that VORO2MESH grids produce simulation results very close to locally refined grids created using the Quadtree approach, and simulation activities are substantially improved using TOUGH2Viewer.