7.4. Initial Conditions

To solve the groundwater flow equation, MINEDW requires an initial estimate for the head values (initial conditions). The initial conditions can be specified by either defining a constant-head value or reading varied head data from a file created in a previous model run.

To define the initial conditions:

• Select “Initial Heads” from the “Project” drop-down menu on the Main Menu banner

• The dialog box shown in Figure 7.26 appears

Figure 7.26 The “Set Up Initial Head“ dialog box

Constant:

The initial head for all the nodes is a constant value, which is input in the field provided.

Varied:

The initial head for all the nodes is imported from a file created by a previous model run. MINEDW records the groundwater head for the entire model domain at the last time step of a model run in an .MDL file. This is done for both steady-state and transient model simulations.

To use this information as the initial condition for a subsequent model run:

• Click on “Varied”

• Click the “…” button to the right

• Select the .MDL file from the folder where MINEDW previously ran (must be the same model domain)

The .MDL file format contains 10 columns of head data. The file length varies with model size, with head values corresponding to nodes from first to last, reading left to right and top to bottom.