Step-by-Step Guide to Download 10 Free DEMs in QGIS

Step 1: Install the OpenTopography DEM Downloader Plugin

To start downloading Digital Elevation Models (DEMs), you first need to install the OpenTopography DEM Downloader plugin in QGIS. Follow these steps:

• Open QGIS and navigate to the Plugins section.
• Click on Manage and Install Plugins.
• In the search field, type OpenTopography DEM Downloader.
• Select the plugin and click Install Plugin.

Step 2: Request an API Key

To use the plugin, you need an API key. Here’s how to get one:

• Visit the plugin’s homepage by clicking on the Homepage option in the plugin description.
• Follow the link to request an API key.
• If you don’t have an account, create a new account and confirm it.
• Copy your API key after logging in.

Step 3: Configure the Plugin in QGIS

After obtaining your API key, you’ll need to configure the plugin:

• Select a base map to visualize your target area.
• Zoom in on the area where you want to download the DEM.
• Click on the plugin and enter your API key in the specified section.

Step 4: Select and Download Your Desired DEM

Now, it’s time to select the type of DEM you want to download:

• In the plugin, choose the desired DEM type, for example, SRTM 90 meter.
• Specify the area for the download by drawing a range on the map.
• Click the Run option to start the download.

Step 5: Download Additional DEMs

You can repeat the previous step to download different types of DEMs:

• Select another DEM type, such as DEM 30 meter.
• Draw the desired range again and wait for the download to complete.

Step 6: Customize the DEM Visualization

Once your DEMs are downloaded, you can customize their appearance:

• Set a color combination for better visualization.
• Specify the render type and select a suitable color ramp.

DEM’s available from OpenTopography

1. **SRTM 90m**: The Shuttle Radar Topography Mission (SRTM) 90m DEM provides elevation data with a spatial resolution of 90 meters. It was generated using radar interferometry during a space shuttle mission in 2000 and covers much of the Earth’s land surface.

2. **SRTM 30m**: Similar to the SRTM 90m, the SRTM 30m DEM offers a higher resolution of 30 meters. It is derived from the same mission data, providing more detailed elevation information for various applications, including topographic mapping and terrain analysis.

3. **ALOS World 3D 30m**: The Advanced Land Observing Satellite (ALOS) World 3D dataset features a resolution of 30 meters and provides global elevation data. It is produced from ALOS satellite data and is particularly useful for applications in land use, environmental monitoring, and disaster management.

4. **SRTM GL1 Ellipsoidal 30m**: This DEM is a refined version of the SRTM data, corrected to fit an ellipsoidal reference surface. With a resolution of 30 meters, it is useful for geodetic applications and provides accurate elevation information.

5. **Global Bathymetry SRTM15+ V2.1**: This dataset extends the SRTM methodology to bathymetric data, providing information on ocean depths. The SRTM15+ V2.1 product offers a global view of seafloor topography and is utilized in marine research, navigation, and environmental monitoring.

6. **Copernicus Global DSM 30m**: The Copernicus Global Digital Surface Model (DSM) at 30m resolution is part of the Copernicus program and includes elevation data that captures the heights of the Earth’s surface, including vegetation and buildings. It is valuable for urban planning, forestry, and environmental assessments.

7. **Copernicus Global DSM 90m**: This is a coarser resolution version of the Copernicus DSM, with a 90-meter resolution. It serves similar purposes as the 30m version but is suitable for broader analyses where high detail is less critical.

8. **NASADEM Global DEM**: NASADEM combines data from multiple sources, including SRTM and other satellite missions, to create a global elevation model. It offers improved accuracy and updates over previous DEMs and is particularly useful in scientific research and environmental studies.

9. **Europe DTM 30m**: This Digital Terrain Model (DTM) for Europe, at a resolution of 30 meters, focuses on representing the bare ground surface without vegetation and man-made structures. It is essential for hydrological modeling, land use planning, and topographic analyses.

10. **GEDI L3 Grid 1km**: The GEDI (Global Ecosystem Dynamics Investigation) L3 Grid provides a 1-kilometer resolution DEM derived from lidar data collected by the GEDI instrument aboard the International Space Station. It focuses on forest canopy height and structure, facilitating ecological research and carbon stock assessments.

FAQ

What is a DEM?

A Digital Elevation Model (DEM) is a 3D representation of a terrain’s surface created from terrain elevation data. It is widely used in geographic information systems (GIS) for various analyses.

Why do I need an API key?

The API key is necessary to access the OpenTopography data services and to ensure secure and authorized access to the datasets.

What types of DEMs can I download?

You can download various types of DEMs, including SRTM data at different resolutions such as 30 meters and 90 meters.

Can I use the downloaded DEM in other software?

Yes, once downloaded, the DEM can be used in various GIS software, including QGIS, ArcGIS, and more for further analysis and visualization.