SMS:TUFLOW 2D Geometry Modification Coverage Properties Dialog

Geometry modifications are used to raise/lower elevations along an arc or within a polygon. This is useful for representing levees, ridges, gullies, or future cut/fill scenarios.

The options specified in the coverage properties dialog apply to any geometry modification arcs and polygons within the coverage. If you want to use multiple settings within a simulation, you must have multiple geometry modification coverages.

Z Values

The z values determine how the elevations in the coverage are used to modify the existing model elevations. The options are:

1. All Zpts (default) - The z values from all of the arcs/polygons are used.
2. Min - The z values from the arcs/polygons will only overwrite the existing elevations if the elevations are lower.
3. Max - The z values from the arcs/polygons will only overwrite the existing elevations if the elevations are higher.
4. Add - The z value becomes the existing elevation plus the z value from the arc/polygon (which may be negative).

Thick Arcs

If this option is not selected, the z values of the arc will be applied to the nearest elevation locations in each cell that the arc passes through. Otherwise, the arc elevations will be applied to every elevation location in each cell that the arc passes through.