What is it?
A prescribed head boundary condition assigned to a polyline that utilizes the surface stage to assign the hydraulic head in the adjacent aquifer model cells.How to use it:
Spatially-constant prescribed head. Select the radio button next to ‘Constant’, and enter the desired head value (in meters) in the text box. To assign spatially-constant but time-dependent head values, leave the ‘Constant’ radio button selected, but also check the radio box next to ‘Transient’. Then LM click the ‘Transient’ button to open the sub-menu for editing/inputting transient head data.Multiple options are available if a spatially-variable prescribed head is desired. First, one may select the radio button next to ‘Equal to Y (e.g., Water Table) to assign a head value equal to the water table elevation at each point along the polyline. Another option is to select the radio button next to ‘Variable’ option from the Prescribed-Head option box, then LM click the ‘>>more’ link to open the Edit Polyline Attributes sub-menu.