The Slope (Terrain analysis) tool calculates the slope angle of each raster cell in degrees.
To calculate the slope of the terrain (Fig. 102):
- Go to Raster.
- Select Terrain analysis.
- Choose Slope.
- Choose the DEM as the input raster.
- Browse for a destination path and save the output raster as “slope”.
- Choose the output format to be used from the list (various formats within GDAL).
- Click OK.
- Adapt the raster symbolization if necessary (Layer Properties > Symbol).
Besides the Terrain analysis
tools there is a set of Terrain analysis
functions (with even more options) provided by the GDALTools Plugin (Fig. 103): these tools are accessible by menu Raster > Analysis > DEM (Terrain
Fig. 102. Calculating slope with QGIS.