How to create an elevation profile

QGIS Window showing Profile Tool

Elevation profiles are best generated using a geographic information system such as QGIS. To achieve acceptable speed and responsiveness, this software requires a computer fitted with a good graphics card, and also a fast internet connection as imagery is generated on the fly and not stored locally.

To create an elevation profile using QGIS one must first install three plugins:

  • QuickMapServices (to load the required underlying OpenStreetMap base map)
  • NASA SRTM (to load the elevation data)
  • Profile Tool (to generate the profile along any user-defined line).
Installing the OpenStreetMap Base Map
  1. Launch QGIS.
  2. From the “Project” tab on the menu bar, select “New” to create a new project. 
  3. From the “Project” tab on the menu bar, select “Save” to save the project. 
  4. Select “Plugins” from the QGIS menu bar.
  5. Select “Manage and Install Plugins”. 
  6. From the search bar of the Plugins window, type and search “QuickMapServices”. 
  7. Select “Upgrade” to download a new version of the plugin, where applicable. 
  8. Click “Install” to install the “QuickMapServices” plugin. 
  9. From pool of tools on the menu bar, select “Web”. 
  10. Toggle to “QuickMapServices” and select OSM to import the OpenStreetMap base map.
Installing the NASA SRTM Downloader
  1. Select Plugins from the menu bar.
  2. Select Manage and install plugins. 
  3. From the search bar of the Plugins window, type and search SRTM-downloader. 
  4. Select Upgrade to download a new version of the plugin, where applicable. 
  5. Click install to install the SRTM downloader plugin.
  6. From the QGIS menu bar, select Plugin. 
  7. Select SRTM-downloader. 
  8. Toggle to your location of interest. 
  9. From the SRTM-downloader window, click “Set canvas extent”. 
  10. Set “Output-Path” to your desired location folder where the SRTM is to be saved. 
  11. Click “Download”. 
  12. A window appears requesting for your Earthdata login. You will need to register for the NASA Earthdata portal’s Earthdata Login User Registration
  13. Key in the generated login details from Earthdata’s portal into QGIS login window.
  14. Click OK to download the elevation data. 
Installing the Profile Tool Plugin
  1. Select Plugins from the menu bar.
  2. Select “Manage and Install Plugins”. 
  3. From the search bar of the Plugins window, type and search Profile tool. 
  4. Select Upgrade to download a new version of the plugin, where applicable. 
  5. Click install to install the Profile tool plugin. 
  6. From the menu tabs, select Plugins.
  7. Select Profile tool.
  8. Select “Terrain profile”. 
  9. From the Terrain profile window, select “Add Layer”. 
  10. Select the SRTM dataset from the list of your data layers.
  11. Use the drawing tool within the Profile plugin to draw a line across the area where you want the elevation profile. Use the mouse pointer to specify a line on the map canvas over the SRTM data where you would want a cross-sectional profile to be drawn. Start at one location and then click at the end location – the resulting red line represents where data for the elevation cross-section will be collected from the SRTM data.

After drawing the line, the Profile plugin will display a graph. This graph shows the elevation along the line you drew. The x-axis of the graph represents the distance along the line, and the y-axis shows the elevation.

The elevation profile can be analyzed directly within QGIS. You can hover over the graph to see specific elevation values at different points in the map view. The graph will display a tooltip with X and Y values with a corresponding red dot in the map view showing the location.

If needed, you can export the profile to various formats for further analysis or reporting. The Profile tool in QGIS can be used for analyzing cross-section profiles for all types of surface data, not just elevation.