Hydrological & Terrain Analysis using WhiteboxTools
Contents
Introduction
This tutorial demonstrates how to perform hydrological and terrain analysis within QGIS. The workflow begins with downloading a DEM dataset, installing WhiteboxTools, and configuring QGIS to recognize the WhiteboxTools functions. Subsequent steps includes DEM preprocessing, flow direction and flow accumulation modelling, deriving slope and the creation of a Topographic Wetness Index (TWI) map.
Data & Software Requirements
- 30 m DEM of the Kananaskis region
- QGIS
- WhiteboxTools Open Core
Step 0: Installing WhiteboxTools
Download WhiteboxTools
To download WhiteboxTools, head on over to the WhiteboxTools Download Page and download the WhiteboxTools Open Core. After downloading, extract the .zip file and place the folder somewhere easy to find. For example, you may store it in: C:\Program Files\WhiteboxTools\
Configuring WhiteboxTools in QGIS
In QGIS, open Plugins → Manage and Install Plugins. In the search bar, type "WhiteboxTools" and the plugin should appear in the list. Select it and click "Install Plugin".
To configure the path to the WhiteboxTools executable, open Settings → Options → Processing. In the dialogue window, open Providers → WhiteboxTools, and under "WhiteboxTools executable", browse to the folder where you extracted the files and select the file named "whitebox_tools" which is found inside the WBT folder.
Once configured, WhiteboxTools tools will appear in the QGIS Processing Toolbox.
Step 0.5: Downloading the DEM
The digital elevation model (DEM) used in this tutorial is the Copernicus GLO-30 Digital Elevation Model, downloaded through the OpenTopography portal.
Feel free to use your own DEM, but if you wish to follow the tutorial with the exact dataset shown here, go to the Copernicus GLO-30 Digital Elevation Model.
On the OpenTopography page, scroll down to the "Coordinates" section, check off "Manually enter selection coordinates", and enter the following:
Xmin= -115.44776916503906 Ymin= 50.68473994828557 Xmax= -115.0165557861328 Ymin= 51.03926216055825
Before submitting the request, ensure the output format is set to "GeoTiff".
