Tutorial 1 Boundary Conditions

To view the boundary conditions window, select "Boundary Conditions" from the "Show" menu. To manipulate them you must select "Boundary Conditions" from the "Active Data" selector.

Boundary conditions are specified by recharge period, so it is necessary to have the "Recharge Period" window showing when setting them. The user must highlight the period of interest. Boundary conditions can then be set along any segment of the domain boundary (either external or internal).

For this example, land surface is represented as a specified flux boundary condition (green color) with the flux set at 0.01 m per day. The temperature of inflowing water is set to 10 oC. For the first recharge period the stream bed is represented by a constant pressure boundary condition (blue). The temperature of the inflowing water is set at 30 oC. (NOTE, this is the only difference in boundary conditions between the 2 recharge periods.)

The bottom boundary is assumed to be impermeable, so the default "no-flow" boundary condition is used. Temperature at that boundary is fixed at 8 oC.

Along the vertical side, the boundary is divided into 3 segments. The upper half of the side boundary is specified as no-flow. The lower portion above the initial water table is specified as a potential seepage face (gold). This designation allows outflow if the water table rises. Below the initial water table, the side boundaries are set to specified total head of -4.5 meters (blue). The negative sign results from the convention of setting the datum to the zero tick mark of the vertical ruler. When the total head is below the zero tick mark, the value is negative.

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