Entering and Editing Quasi-Unsteady Flow Data

The 1D sediment model in HEC-RAS can use unsteady or quasi-unsteady hydraulics.
The main HEC-RAS user manual includes a section on entering and editing unsteady hydraulic data.

However, quasi-unsteady hydraulics apply almost exclusively to sediment transport modeling.  Therefore, they are included here.

The quasi-unsteady approach approximates a flow hydrograph by a series of steady flow profiles associated with corresponding flow durations (see the quasi-unsteady section of the Technical Reference Manual).

This analysis requires different information than steady or unsteady flow: a separate quasi-unsteady flow dialog is available by selecting Quasi-Unsteady Flow under the Edit menu of the main HEC-RAS dialog or by pressing the Quasi-Unsteady Flow shortcut button.