Selecting Inputs

Each scenario references a specific set of inputs. Changing inputs creates a new scenario variant without modifying the original data.

Required inputs

Every scenario needs at minimum:

• Elevation — the DEM raster
• Boundary — domain boundary lines
• Inflow — at least one rainfall polygon or surface flow line

Optional inputs

Input	Effect if omitted
Friction	Default Manning's n (0.04) applied everywhere
Structures	No buildings — flat terrain only
Mesh Regions	Uniform mesh resolution across entire domain
Catchment	No hydrological routing

Comparing scenarios

You can create multiple scenarios within a project, each with different inputs or parameters. This is useful for:

• Sensitivity analysis — vary one input at a time
• Design comparison — test existing vs proposed conditions
• Climate scenarios — run different rainfall intensities