An exterior-interior stage transform function relates the water surface elevation in the channel (exterior) to the water surface elevation in the floodplain (interior). To create an exterior-interior stage transform function:

  1. From the Study Tree, under Stage Transform Functions, right-click on Exterior-Interior Functions and select the create new option.
    Exterior-Interior functions shortcut command options for creating or importing relationships.
  2. Enter the name for the function and a description (optional, but recommended). 
  3. Select the Distribution Type from the options: 
    • Deterministic (default selection)
    • Uniform
    • Normal
    • Triangular
    • LogNormal
  4. Enter the paired data with or without uncertainty. The X Value column should have external stages and Y Value column(s) should specify the corresponding interior stage.
    Example of the Create New Exterior-Interior Relationship dialog with the Distribution Type list.
  5. Click Save and Close to create the transform function.