Digital Elevation Models (DEMs) are essential for various geospatial projects, from hydrological modeling to terrain analysis. The Shuttle Radar Topography Mission (SRTM) provides one of the most widely used DEM datasets. If you are a QGIS user, you can download this data directly within the software.

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The Advantage of Using QGIS

Using QGIS for downloading SRTM DEM data offers a seamless experience. You will not need to toggle between external platforms or leave your QGIS workspace. Everything can be done with just a few clicks.

What Is SRTM Data?

SRTM data was collected in February 2000 during an 11-day Space Shuttle Endeavour mission using interferometric synthetic aperture radar (InSAR). The dataset covers land areas between approximately 56°S and 60°N latitude — roughly 80% of Earth’s total land surface. Two resolutions are commonly available: 1 arc-second (approximately 30 m) global coverage, and 3 arc-second (approximately 90 m). The data is distributed by NASA and the United States Geological Survey (USGS).

Setting Up the SRTM Downloader Plugin

• Start by opening your QGIS workspace.
• Navigate to Plugins and select Manage and Install Plugins.
• Search for the plugin named SRTM Downloader.
• Click on the plugin to install it.
• Once installed, you will find the SRTM Downloader listed under the plugins.

Note: The SRTM Downloader plugin (version 3.3 and later) downloads tiles via OpenTopography and requires a free OpenTopography API key. Register at the OpenTopography website, then paste your API key into the plugin settings before downloading.

Preparing Your Workspace

Before downloading the DEM data, it is helpful to have a base map to guide you.

• Install another plugin called Quick Map Services.
• Once installed, go to Web and select the Quick Map Services plugin.
• Choose OSM Standard to add OpenStreetMap as your base map.
• After adding the base map, ensure the coordinate reference system is set to EPSG:4326 (WGS 84 Geographic Coordinate System). This ensures proper alignment with the SRTM data source.

Downloading the DEM Data

• Zoom into your area of interest on the map.
• Use the zoom-in tool to refine and draw a rectangle around the desired area.
• Open the SRTM Downloader plugin.
• Set the canvas extent, and the plugin will automatically determine the boundaries of your specified area.
• Click the download button.
• If you have not yet entered your OpenTopography API key, the plugin will prompt you to do so. Register for a free API key at the OpenTopography website, then enter it in the plugin settings.

Working with the Downloaded Data

• After downloading, the DEM tiles will appear in your QGIS interface.
• If you wish to merge multiple tiles into one, go to Raster, then Miscellaneous, and select Merge.
• Choose all the layers you want to merge and run the process.
• The result is a single raster file — a mosaic of the selected tiles.
• You can customise the appearance of the DEM by changing its colour scheme. For instance, use the single-band pseudocolour renderer to differentiate between higher and lower elevations.
• To save the DEM as a separate file, right-click on it, select Export, then Save As, and choose the desired format.

Conclusion

Downloading SRTM DEM data using QGIS is a straightforward process. Once you have obtained a free OpenTopography API key and configured the SRTM Downloader plugin, you can download DEMs for any region within SRTM coverage — roughly 56°S to 60°N latitude — without ever leaving your QGIS project.

Frequently Asked Questions About Downloading SRTM DEM Data Using QGIS

What is SRTM DEM data, and why is it important?

SRTM (Shuttle Radar Topography Mission) DEM (Digital Elevation Model) data represents the Earth’s surface topography. Collected in February 2000 aboard Space Shuttle Endeavour, it is widely used for terrain modelling, flood risk assessment, landscape planning, and hydrological analysis. It covers land areas from approximately 56°S to 60°N latitude.

Why should I download SRTM DEM data directly within QGIS instead of using external platforms?

Downloading directly within QGIS eliminates the need to toggle between platforms or manually import and export data. It streamlines the workflow and enhances efficiency.

How do I install the SRTM Downloader plugin in QGIS?

Open QGIS, navigate to Plugins, select Manage and Install Plugins, search for SRTM Downloader, and click install.

Are there any other plugins I need to install for this process?

Yes, it is recommended to install the Quick Map Services plugin to add a base map, which helps when specifying the download area.

Why is it necessary to have a base map before downloading the DEM data?

A base map provides geographic context, helping you accurately navigate and specify the area of interest for the DEM data download.

What is the significance of setting the coordinate reference system to EPSG:4326?

EPSG:4326 (WGS 84 Geographic Coordinate System) ensures proper alignment with the SRTM data source. It is essential for capturing coordinates accurately so the downloaded data aligns correctly in your project.

How do I specify the area for which I want to download the DEM data?

Zoom into your area of interest on the QGIS map and draw a rectangle around the desired area. The SRTM Downloader plugin will use this extent for downloading.

What should I do if the SRTM Downloader prompts me for credentials?

Current versions of the SRTM Downloader plugin (3.3 and later) use an OpenTopography API key rather than NASA Earthdata credentials. Register for a free API key at opentopography.org and enter it in the plugin settings.

Can I merge multiple DEM tiles into a single file? If so, how?

Yes. In QGIS, go to Raster, then Miscellaneous, and select Merge. Choose all the layers you want to merge and run the process. The result will be a single raster mosaic file.

How can I customise the appearance of the downloaded DEM data?

In QGIS, open the layer properties for the DEM layer. From there you can change the colour scheme, assign a colour ramp, and make other visual adjustments using the single-band pseudocolour renderer.

Is there a way to save the DEM data in a different format or export it for use in other software?

Yes. Right-click on the DEM layer in QGIS, select Export, then Save As, and choose your desired format.

Can I repeat this process for different areas without starting from scratch?

Yes. Simply zoom into a new area of interest in QGIS and follow the same steps to download the DEM data for that region.

Are there any limitations to the regions I can download DEM data for using this method?

SRTM data covers land areas between approximately 56°S and 60°N latitude — roughly 80% of Earth’s total land surface. Polar regions beyond those latitudes are not included in the SRTM dataset. For most global regions within that range, data is freely available.

What should I do if I encounter errors or issues during the download process?

Ensure your internet connection is stable and that your OpenTopography API key is correctly entered in the plugin settings. Double-check the specified area and coordinate reference system. If issues persist, consult the QGIS community forums or the plugin documentation for troubleshooting guidance.