QGIS is free and open source software. It is a Geographical Information System (GIS). QGIS enables users to create, manipulate, and visualize spatial data. Spatial data is data associated to a location or a place, commonly defined in terms of vector (points, lines, or polygons) or raster (bitmap) data. QGIS 3 was a significant update in the QGIS series.
QGIS runs on most operating systems. It is even possible to install it on a Raspberry Pi! This is one of the reasons for the success of QGIS: it is supported on multiple platforms. The QGIS project provides ready-to-use packages as well as instructions to build from source code at QGIS page. In this article, we will cover how to install QGIS on two systems: Windows and Ubuntu.
This post is taken from the book, QGIS Quick Start Guide by Packt Publishing, written by Andrew Cutts. This book will help learn how to load GIS data, creating GIS data, styling GIS and making maps with QGIS following a simple narrative that will allow you to build confidence as you progress.
The processing framework of QGIS3 was rewritten and has improved the performance significantly. Now, QGIS 3 provides users’ access to Python 3. This means many of the plugins, that make QGIS so powerful, have been updated to be compatible with the new API.
Installing QGIS on Windows
There are two ways of installing QGIS on the Windows OS. Directly download the .exe file from QGIS page, or download it via the OSGeo4W installer. OSGeo4W is a small program that allows you not only to download and install QGIS, but also other OSGeo tools. We recommend that you use this installer for QGIS. You can download the 32-bit or the 64-bit OSGeo4W installers from OSGeo, or, you can download directly from OSGeo setup or OSGeo 4 setup. Download the version that matches your operating system and keep it. In the future, whenever you want to change or update your system, just run it again.
OSGeo4W installer
In this section, we will look at the advanced installer and express installer options (which will install the latest release) using OSGeo4W as the installer.
Latest release
Once you have downloaded the installer that matches your system, double-click on the .exe file and step through the following installation screens. The simplest way, which installs the latest release, is to select Express Desktop Install. This may not install QGIS 3.4. If you wish to do this, then please see the following subsection, Advanced installer. The express installation option is shown in the following screenshot:
OSGeo4W setup
Select the checkboxes next to QGIS, GDAL, and GRASS GIS. GDAL is used for reading and writing geospatial data and GRASS GIS is open source GIS software that can be used in combination with QGIS. This is shown in the following screenshot:
OSGeo4W setup, choosing options for install
Click Next and the downloading process will begin. Progress will be displayed as each component is downloaded and installed. Having these installed will provide you with many tools to perform geospatial analysis. After a short period of time, you should see OSGeo4W in your program menu, along with a subset of the software installed, including QGIS.
You can install multiple versions of QGIS. Sometimes, this may be necessary as plugins may not work with certain versions of the software. What if you want to choose a version? OSGeo4W allows this with the advanced installer.
Advanced installer
Run the OSGeo4W .exe file and select the radio button next to Advanced Install:
OSGeo4W setup (choosing Advanced Install)
Step through the installation wizard. When you get to Select Packages, choose the version you require. In the following screenshot, I have selected 3.4:
OSGeo4W setup (selecting packages to install)
You can select other packages if required. Once you have chosen the software, click on Next and the installation will begin.
Updating via OSGeo4W
You can use the OSGeo4W installer to install new updates. It will uninstall the previous version. You may have older versions installed on your system (perhaps installed with the standalone installer). To uninstall, locate the installation directory of the older version and run the uninstall.exe file. This is shown in the following screenshot:
Windows Explorer
Step through the uninstallation wizard and, once uninstalled, you should get a similar message (depending on your version) to this:
Uninstalling QGIS 2.18
Click on Finish to exit.
Installing on Ubuntu
On Ubuntu, the QGIS project provides packages for the LTR, Latest Release (LR), and development versions (DEV). For this book, we recommend installing the LTR version. The LTR version is the current most stable version of the software.
To avoid conflicts that may occur due to incompatible packages, make sure that you only add one of the package source options. The specific lines that you have to add to the source list depend on your OS version. The following version is the latest release for Debian stretch:
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deb https://qgis.org/debian stretch maindeb-src https://qgis.org/debian stretch main
After choosing the repository, we will add the qgis.org repository’s public key to our apt keyring. This will avoid the warnings that you might otherwise get when installing from a non-default repository. Run the following command in Terminal:
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wget -O – https://qgis.org/downloads/qgis-2017.gpg.key | gpg –importgpg –fingerprint CAEB3DC3BDF7FB45gpg –export –armor CAEB3DC3BDF7FB45 | sudo apt-key add –
Finally, to install QGIS, run the following commands. The first will fetch any updates to packages on your system; the second will install QGIS, the Python library, and the GRASS plugin:
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sudo apt-get updatesudo apt-get install qgis python-qgis qgis-plugin-grass
Using QGIS
Open QGIS from the installation location. If you followed the OSGeo4W installation on Windows, you should find it in under the OSGeo4W Shell folder in the Start menu. On loading, QGIS will appear similar to the following screenshot which I have annotated:
Overview of QGIS 3 annotated
The biggest area is reserved for the map.
In this article, we discussed how to get started with QGIS3 on Windows and Ubuntu. If you are interested to work with GIS data, this step by step guide on QGIS will help you from creation to making a map, read the book QGIS Quick Start Guide on Packt Publishing.
Source: Packt Publishing
