The SFT: Stream Flow Transport Package pane is is on the MODFLOW Packages and Programs dialog box under MT3DMS or MT3D-USGS. It is used to specify some of the data for the SFT package in MT3D-USGS. The SFT package is not included with MT3DMS. The Stream Flow Transport Package in MT3D-USGS can only be used if the groundwater flow model is a MODFLOW-NWT model.
Besides comments, several other variables are specified on the SFT: Stream Flow Transport Package pane.
Simulate solute transport though stream (NSFINIT): If this checkbox is checked then surface-water transport is solved in the stream network while taking into account groundwater exchange and precipitation and evaporation sources and sinks. Otherwise, the surface-water network as represented by the SFR2 flow package merely acts as a boundary condition to the groundwater transport problem; transport in the surface-water network is not simulated.
Lose solute mass through evaporation (IETSFR): signifies whether or not mass will exit the surface-water network with simulated evaporation. If the checkbox is checked, mass is allowed to exit the simulation with the simulated evaporation. Otherwise, mass does not leave via stream evaporation.
Stream solver time weighting factor (WIMP): WIMP is a real number that ranges between 0.0 and 1.0 and is the stream solver time weighting factor. Values of 0.0, 0.5, or 1.0 correspond to explicit, Crank-Nicolson, and fully implicit schemes, respectively.
Stream solver space weighting factor (WUPS): WUPS is a real number that ranges between 0.0 and 1.0 and is the space weighting factor employed in the stream network solver. Values of 0.0 and 1.0 correspond to a central-in-space and upstream weighting factors, respectively.
Closure criterion (CCLOSESF): CCLOSESF is a real number and is the closure criterion for the SFT solver.
Maximum number of iterations (MXITERSF): MXITERSF is an integer value limiting the maximum number of iterations the SFT solver can use to find a solution of the stream transport problem.
Solution information (IPRTXMD): IPRTXMD is a flag to print SFT solution information to the standard output file.
•IPRTXMD = 0 means no SFT solution information is printed;
•IPRTXMD = 1 means SFT solution summary information is printed at the end of every MT3D-USGS outer iteration; and
•IPRTXMD = 2 means SFT solution details are written for each SFT outer iteration that calls the xMD solver that solved SFT equations.
