MAW: Multi-Aquifer Well Package Pane

The Multi-Aquifer Well package simulates wells whose open intervals extend beyond a single model cell. The pane for this package is on the MODFLOW Packages and Programs dialog box under Head Dependant Flux. The Multi-Aquifer Well package is part of MODFLOW-6.

Only point objects on the top view of the model that have zero Z formulas can be used to define Multi-Aquifer wells.

On the MAW: Multi-Aquifer Well package pane, the user sets six inputs for the Multi-Aquifer Well package.

Print MAW heads to listing file Checking this check box activates the PRINT_HEAD option in the MAW package. It causes the multi-aquifer well heads will be printed to the listing file.

Save binary MAW heads file (.maw_head) Checking this check box activates the HEAD FILEOUT <headfile> option in the MAW package. It causes the multi-aquifer well heads to be saved to a binary file with the extension ."maw_head."

Save binary MAW budget file (.maw_bud) Checking this check box activates the BUDGET FILEOUT <budgetfile> option in the MAW package. It causes the multi-aquifer flow budget terms to be saved to a binary file with the extension ."maw_bud."

Include well storage (inverse of NO_WELL_STORAGE) Checking this check box deactivates the NO_WELL_STORAGE option in the MAW package. The NO_WELL_STORAGE option deactivates inclusion of well storage contributions to the multiaquifer well package continuity equation. Thus when this checkbox is checked, well storage is included in the well package continuity equation.

Shutdown theta is a value that only applies to wells that use the HEAD_LIMIT option. SHUTDOWN_THETA is used to control discharge rate oscillations when the flow rate from the aquifer is less than the specified flow rate from the aquifer to the well. Values range between 0.0 and 1.0, and larger values increase the weight (decrease under-relaxation) applied to the well discharge rate. The head limit option has been included to facilitate backward compatibility with previous versions of MODFLOW but use of the rate scaling option instead of the head limit option is recommended. By default, SHUTDOWN THETA is 0.7.

Shutdown kappa is a value that only applies to wells that use the HEAD_LIMIT option. SHUTDOWN_KAPPA is used to control discharge rate oscillations when the flow rate from the aquifer is less than the specified flow rate from the aquifer to the well. Values range between 0.0 and 1.0, and larger values increase the weight applied to the well discharge rate. The head limit option has been included to facilitate backward compatibility with previous versions of MODFLOW but use of the rate scaling option instead of the head limit option is recommended. By default, SHUTDOWN KAPPA is 0.0001.