ANALYSIS OF A LONG-TERM PUMPING AND TRACER TEST USING THE CHANNEL NETWORK MODEL

Water flow and solute transport in a fractured medium are described by the Channel Network model, CHAN3D. In the field and in the model, mos t of the flow and transport take place in fracture zones. CHAN3D was u sed to simulate a long-term pumping and tracer test called LPT2. In th e first simulations, no calibrations, conditioning or parameter adjust ments were made to better fit the experimental results. Instead, as mu ch as possible of the available field data were used. In six different paths the simulations predicted breakthrough that should be observabl e. However, only two of the performed tracer tests resulted in breakth rough of solutes. Some possible reasons for the scant recovery is disc ussed. In the analysis of LPT2, the impact of the flow rates at the in jection positions, flow porosity and interaction with the rock matrix were studied. (C) 1998 Elsevier Science B.V. All rights reserved.