What is it?
Boundary conditions describe flow and/or head conditions along the lateral, bottom, and top spatial boundaries of the flow model. Initial conditions describe the head/flux spatial distribution at the starting time (t=0) of the model simulation.How to use it:
INITIAL CONDITIONS.The ‘Top’ option will use the Top Elevation surface assigned by the user.
The ‘Parent’ option uses the head distribution of a larger Parent model spanning the new (Child) model domain. Head values are interpolated from the (coarse-grid) Parent model to the (finer-grid) Child model.
The ‘Constant’ option will assign the value in the text box as a constant head value across the entire domain.
Check the box next to ‘Overwrite with Steady State Solution at t=0’ to use the head distribution solved for steady state conditions as the initial head distribution of the transient simulation.
BOUNDARY CONDITIONS.
Be default, the conditions along the domain’s lateral and bottom boundaries are ‘no-flow’ (i.e. flux across the boundary is zero at all points). However, lateral boundary conditions can be derived from a previous simulation result encompassing the study area.
To do this, check the box next to ‘Boundary Condition from Parent Model’ after drawing the “Child” model zone (submodel zone) within the Parent Model domain. Assigning a zone as the submodel domain is done in the Flow Property tab of the Zone Attributes menu (see Zone Types Real-time Help). (Alternatively, the user may draw a new domain polygon, but the parent model and all of its conceptual features that lie outside of the new submodel boundary will be removed).
By default, the boundary conditions are derived from the last simulation run on the IGW-NET user account. To use a previously saved result, check the box next to 'Import', then click Import to browse to the model zipped file with the saved outputs.
NOTE: Boundary conditions can can be derived from both a steady state or transient parent model (for either steady or transient submodel simulations, respectively).
Interpolation of Parent model head values will be applied along the boundary of the (finer-grid) submodel.