How to Calculate the Slope of a DEM in 3 Steps:
- Open the DEM in QGIS
- Fill Sinks
- Run The Slope Tool
Step 1
Open the DEM in QGIS
In this example, we use a DEM shapefile exported from the Equator Site Builder. Open your DEM shapefile in QGIS by simply dragging and dropping it into the map space:
Image of our DEM in QGIS
Step 2
Fill Sinks
Next, we will fill in the sinks, using Fill sinks (wang & liu) tool:
Processing Toolbox → SAGA → Fill sinks (wang & liu)
Using the fill sinks tool to generated a Filled DEM layer
Step 3
Run The Slope Tool
Now that we have projected our DEM onto our project, we will run the Slope tool:
Processing Toolbox → Slope
Set the input layer as your DEM, and adjust the other input settings as you deem appropriate (in this case we elected to leave the default settings):
Using the Slope tool to generate the final layer
Done!
By now you should have a layer with the slope of your DEM calculated in degrees! We hope this helped, and feel free to take a look at some of Equator’s other blogs and “How-to tutorials”!
