About the flood theme

In InfoWorks ICM, the flood theme provides a comprehensive picture of all water levels across 1D and 2D object results.

Flood Extents:

Within the flood theme, flood extents are implemented as follows.

• River reaches - water surface triangulated between known water levels at river sections and along bank lines
• 2D zones - elements treated as horizontal surfaces
• Storage polygons- single horizontal surface for whole polygon

Depth contours obtained by subtracting ground model ground level from water surface.

To produce flood contours, open set of results with ground model loaded into GeoPlan.

Where rainfall is applied directly to mesh, adjusting Minimum calculated depth where theme applies removes noise created by shallow sheet flow.

Element vs. Flood Theme:

Noticeable differences when comparing examples of 2D elements theme and flood theme:

• Granularity of flood results matches ground model grid, not mesh element sizes, which are typically much larger.
• Some detail lost in meshing, such as drainage channels, is built back into results representation.
• Flood theme displayed within river reach and bridge polygons, providing more complete picture of water level results.

Common to use 2D elements themes when inspecting results, but flood theme can provide comprehensive picture and build detail back into results simplified for simulation.

Flood Theme 3D View:

Depending on resources, can also present 3D view of results with flood theme active.

Can make it easier to conceptualize certain elements.

Useful when presenting results to stakeholders or public.