For those who are working with Digital Terrain Models, the topographic profiles (or field profiles) are a basic tool, either in the validation or in the processing phase. They make it possible to visualize the relief as a function of the route in a graph where the horizontal axe refers to the distance and vertical axe, the altitude.
Even if there are many specific software, here we will only see the two main GIS software: ArcGis and QGis.
For both examples, we will assume that you have a DTM displayed in the map window.
How to create a terrain profile with ArcGis (10.3)
You can use ArcMap, but, for the time being, not ArcGis Pro. They are in the 3D Analyst extension, not in the toolbox but in the toolbar.
To display: menu Personalize -> Toolbar -> 3D Analyst
How to create the path for the topographic profile
You will create the desired path by clicking on your DTM. Although not very intuitive, you will use the toolbar key : ” Interpolate a 3D line “
Click on the points representing your trip, and finish with a double-click.
To view the profile, use the ” Profile diagram “
The topographic profile opens:
The profile shows neatly but the aesthetics are far from being great. Besides, you may want to save, or include the profile in the layout, or, maybe, add it to a report …
It’s doable! You just must know that you have to right-click on the diagram to open the menu …
The item properties allow you to change the title and subtitle.
Export offers you the actual export in various graph formats ( jpeg, png, svg, …)
Add to the Layout the diagram in the layout.
Another hidden option is the possibility to create a shape file containing the path with the corresponding elevations
This is not in our targeted diagram. This option must be configured BEFORE creating the diagram. In the 3D Analyst toolbar, open the 3D Analyst -> Options -> Diagram Data drop-down menu and configure “Profile chart location data records” by pointing to the directory where you want to store your diagrams.
Each time you create a diagram, the corresponding shape file is created in this directory. The files are named PG and the sequence number of the diagram (PG 1, PG 2, …).
How to create a terrain profile with QGis (2.8)
To create the topographic profile under QGis, you need to load the plugin « Profile Tool “
The installation adds the button in the QGis toolbar:
Clicking on the button the Profile Tool window opens at the bottom of the cartographic window.
The cursor is then in ” input “. You click on the points that make up your trip. To finish, double-click.
The profile appears in the Profile Tool window
You can see the table of the corresponding values, and you can, also, copy the table to the clipboard and retrieve it in a spreadsheet.
You can select the format (pdf, png, svg, PS) and click on « SAVE AS » to save the image