Tutorial: Create a groundwater level map from borehole data and a DEM

6. Download the SRTM 1-Arc Second DEM

In this section we're going to add a DEM to the project. We'll use the Shuttle Radar Topography Mission (SRTM) 1 Arc Second product. This is a free DEM that covers 56°S to 60°N and has a spatial resolution of approximately 30 m on the equator.

You can download the SRTM tiles from the USGS Earth Explorer website or through a plugin. Here we're going to use the SRTM Downloader plugin in QGIS.

1. In the main menu go to Plugins | Manage and Install Plugins...

2. Look for the SRTM-Downloader plugin,  install the plugin and return to the project.

3. In the toolbar click this button to open the SRTM-Downloader dialogue .

4. In the SRTM-Downloader dialogue click Set canvas extent (make sure you're still zoomed to the boundary of the study area!). For the Output-path browse to the folder where the data for this project is stored.

5. Click Download.

6. The first time a popup will promt for the Login information. In order to download the SRTM tiles you need to make an account at https://urs.earthdata.nasa.gov/users/new.

7. Fill in your Username and Password. Click Save Credentials and click OK.

Now it will start downloading the SRTM tile that covers the study area.

8. Click OK in the popup.

9. Close the dialogue.

As you can see the SRTM tile is much larger than our study area. In the next section we're going to clip and reproject the DEM.

SRTM tile added to project