Slope Map¶
Use this dialog to create a slope map (steepness map). The starting point is a terrain model, and the result is polygons for the different slope intervals.
Where can I find the dialog?¶
In the toolbox for Planning, Design, and Execution in the terrain model drawing, select Create thematic map (landscape analysis)...
Specify Slope Values¶
You can enter the terrain slopes manually in the list or use the Standard button to load a default set. The slope can be specified in several ways:
- Degrees
- Percent (per mille)
- Ratio
Editing Values¶
Activate a field in the table for editing by pressing [F2] or by clicking the left mouse button. In edit mode, you can move between columns with [Tab] and [Shift]+[Tab]. Similarly, you can switch rows with [Arrow Up] and [Arrow Down].
Note
The arrow keys can also be used to move between fields when not in edit mode.
By clicking the Standard button, you can load predefined suggestions.
Example of Slope Specification
The slope in the figure can be given as 45 degrees, 100 percent, or 1:1.
Performing the Analysis¶
When the terrain slope intervals are defined, create the slope map by clicking the Execute button. After the analysis is complete, you can paste the polygons onto an application layer. The program includes a template with presentation rules that you can use when creating the application layer.
Slope map example
Triangle model of an approximate hemisphere
The following intervals are defined:
| Ratio | Description |
|---|---|
| 0.050 | 1:20 |
| 0.100 | 1:10 |
| 0.333 | 1:3 |
| 1 | 1:1 |
In this case, you get five polygons:
- One for the interval 0 (flat) – 0.05
- One for the interval 0.05 – 0.1
- One for the interval 0.1 – 0.333
- One for the interval 0.333 – 1.000
- One for the interval 1.000 – 100000 (approximately vertical)
Resulting slope map with color-coded slope intervals