Improved Numerical Modeling of Groundwater Flow and Transport at the MADE-2 Site.
Abstract
Public domain computer programs were used to attempt an improved model of the tritium plume observed during Macrodispersion Experiment 2 (MADE-2), a field scale natural gradient experiment conducted at Columbus Air Force Base, Mississippi. A computational grid having 66 rows, 21 columns, and 9 layers was used. The finite difference program MODFLOW was used to simulate the flow of groundwater through a 330 m x 105 m computational domain. Solutions for the 468 day experiment were obtained using a Sun Sparcstation 2 for several choices of convergence and storage parameters. The simulations had small mass balance errors and were consistent with continuous head observations. The smallest storage coefficients gave the best agreement. The flow model is about as accurate as the data permit. Tritium plume simulations used the mixed Lagrangian-Eulerian finite difference program MT3D to solve the contaminant transport equation using the MODFLOW-predicted flow field. Thirteen runs were made using various advection algorithms and dispersivities, but none was successful. Numerical instabilities or grossly unrealistic predictions ended every run by simulation day 141. Further work is needed to obtain a satisfactory plume prediction. (AN)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1995
- Accession Number
- ADA306092
Entities
People
- Dale F. Rucker
- Donald D. Gray
Organizations
- West Virginia University