1. Introduction to MT3DMS All equations & illustrations taken
from the MT3DMS manual

2. General form of the ADE:
Expands to 9 terms
Expands to 3 terms
(See eqn in Z&B)

4. Assume local chemical equilibrium (LEA):
Isotherms

5. Dispersion
Coefficients

7. This schematic assumes that

8. j-1 j
j+1 x
j-1/2
j+1/2

9. Upstream weighting
Central differences

10. Implicit Approximation
for advection term

12. Explicit Approximation

15. Stability Constraints
for the explicit
approximation

16. MODFLOW MT3DMS MT3DMS time steps are selected by the code considering
stability constraints, if any, and Courant numbers.

17. Courant Number 6 Courant Numbers Cr < 1 One for each face of
the cell block

18.  