Investigating the Macrodispersion Experiment (MADE) site in Columbus, Mississippi, using a three-dimensional inverse flow and transport model
Article first published online: 22 APR 2004
Copyright 2004 by the American Geophysical Union.
Water Resources Research
Volume 40, Issue 4, April 2004
How to Cite
2004), Investigating the Macrodispersion Experiment (MADE) site in Columbus, Mississippi, using a three-dimensional inverse flow and transport model, Water Resour. Res., 40, W04211, doi:10.1029/2002WR001935., , and (
- Issue published online: 22 APR 2004
- Article first published online: 22 APR 2004
- Manuscript Accepted: 30 JAN 2004
- Manuscript Revised: 5 JAN 2004
- Manuscript Received: 20 DEC 2002
- hydraulic conductivity;
- hypothesis testing;
- inverse modeling
 Flowmeter-measured hydraulic conductivities from the heterogeneous MADE site have been used predictively in advection-dispersion models. Resulting simulated concentrations failed to reproduce even major plume characteristics and some have concluded that other mechanisms, such as dual porosity, are important. Here an alternative possibility is investigated: that the small-scale flowmeter measurements are too noisy and possibly too biased to use so directly in site-scale models and that the hydraulic head and transport data are more suitable for site-scale characterization. Using a calibrated finite element model of the site and a new framework to evaluate random and systematic model and measurement errors, the following conclusions are derived. (1) If variations in subsurface fluid velocities like those simulated in this work (0.1 and 2.0 m per day along parallel and reasonably close flow paths) exist, it is likely that classical advection-dispersion processes can explain the measured plume characteristics. (2) The flowmeter measurements are possibly systematically lower than site-scale values when the measurements are considered individually and using common averaging methods and display variability that obscures abrupt changes in hydraulic conductivities that are well supported by changes in hydraulic gradients and are important to the simulation of transport.