QGIS plugins add additional functionality to the QGIS application. There is a collection of plugins ready to be used, available to download. These plugins can also be installed directly from the QGIS Plugin Manager within the QGIS application. Note there are some plugins that have been developed for earlier versions of QGIS that have not been brought into QGIS 3. Its good to monitor new plugin releases as many have been developed to allow access to really useful Australian and Global datasets.
In this tutorial we will load a plugin to access global elevation data. Find the Manage and Install plugins tool:
Search for the SRTM downloader. SRTM stands for the Shuttle Radar Topographic Mission, which is a global 30-meter resolution dataset.
Follow in the install process.
With SRTM downloader you can download elevation tiles for anywhere on earth. However you will first need to create a free account with the USGS service from where the data is provided.
To use the plugin zoom to an area of interest and click download, after verifying your account details it will automatically load the tiles into QGIS.
For the purposes of this tutorial I have already downloaded tiles for Kakadu. You will find them in the elevation folder.
We will use the elevation data to classify the escarpment country in Kakadu and create a slope map. To do this you first need to merge the four elevation data-sets into one layer and then clip it to the Kakadu region.
Step one is to load all of the tiles into QGIS.
Finally right-click and remove all of the tile files and merged layers leaving only the final clipped and warped elevation.