Preliminary Comparison of a Discrete Fracture Model with a Continuum Model for Groundwater Movement in Fractured Dolomite

Abstract: The use of porous-media methods for describing groundwater flow in fractured-rock environments has become commonplace because simulation of flow through discrete fracture networks is difficult and data-intensive. However, the possible errors introduced by the use of the porous-media approximation are rarely addressed or are glossed over in many groundwater studies, and guidelines for when a porous-media approximation is appropriate are almost completely lacking. In this report we present the results of experiments using a two-dimensional stochastic discrete fracture flow model (the SDF model) coupled with a particle-tracking code to explore the validity of the porous-media approximation for simulating groundwater movement in fractured-rock aquifers. The study successfully adapted the fracture-flow model to a microcomputer environment, added capabilities for simulating pumping and injection wells, and developed an advective particle tracking module.