Getting started with QGIS

Getting started with QGIS#

Introducing QGIS#

QGIS is an open source geoinformation system software. That means the source code is available for everyone, making QGIS a free application. The entire source code can be viewed and downloaded on qgis/QGIS.
QGIS is a desktop software: that means you get a program that opens up on your computer as a window with buttons you can click, forms you can fill out to do tasks, and it’s generally a visual interactive experience.
You may view, edit, capture and analyze spatial data or create printable maps with it. QGIS was created in 2002 and is a project of volunteers. And it is constantly changing.
QGIS is backed by a large community of users, so it’s easy to find solutions to technical issues by using QGIS forums, blogs, or sub-reddits. The official QGIS community can be found here. Additionally, a list of helpful websites can be found on the wiki here.

Note

QGIS is constantly changing, with new features being added. Because of this, the newer versions can have changes or even bugs (such as crashes). However, there is always a stable version available, which is supported for longer.

Note

Keep in mind that as QGIS gets developed further, the interface and functions of QGIS are subject to changes. The material written for this platform is referring to QGIS Version 3.36. If the training material is no longer up to date, take a look at the QGIS Documentation.

Working with QGIS#

In QGIS, you create projects where you visualise and manipulate geodata. There are three main workflows you will use: Data collection and creation, data processing, and data visualisation. Geodata is loaded into QGIS projects which will represented as layers on a map canvas.

Hint

There is a lot of complex math involved in the GIS, but QGIS takes care of it on it’s own and you don’t need to have a deep understanding of maths and algorithms to use QGIS. As long as you can use Excel and Powerpoint, you shouldn’t have trouble learning how to use QGIS.

Data Collection and Creation

QGIS offer tools to create your own geodata. For example, with the digitizing tools, you can create points, polygons, and lines with information which can represent spatial information. Furthermore, georeferencing let’s you add geographic information to various types of data, such as satellite imagery or hand-drawn maps. You will learn how to create geodata and how to georeference data in module 2.

Sometimes working with GIS requires you to go and collect the data in the field. In this case, you can use web and mobile apps.

Data Processing

QGIS offers a wide range of algorithms to process geodata. In the following modules, you will get to know a number of algorithms that are especially useful for GIS in humanitarian work. You will learn more about data processing and manipulation in module 2 onwards.

Visualisation

QGIS let’s you visualise geodata and create maps to communicate information. It does so by assigning symbols and colours to different elements in your geodata. Assigning a symbology to the geodata is one of the main skills you will develop as a GIS-user and a good visualisation of data is immensely useful when communicating insights. You will learn how to assign symbols in Module 4: Visualisation of Geodata and Map Making

Opening a new project in QGIS#

Open QGIS like any other program on your computer. The start screen of QGIS usually shows you the projects you worked on recently and the option to create a new project.

There are two options to create a new project:

On the start screen click on Project Template

../../_images/en_project_template_BRC.png

In the upper left corner click on Project -> New Project

Tip

A QGIS project file has the format ending .qgz

Overview of QGIS Interface#

The interface of QGIS is at first glance quite complex. However, once you know all the components you will be able to orientate yourself quickly. Here you can find a description of all components of the interface.

Tip

When you hover with your mouse cursor over icons, text will appear which explains the function of the button.

../../_images/en_QGIS_GUI.png — Fig. 13 QGIS User Interface. Source: CartONG#

Layers List / Browser Panel: The layers list shows all layers/files that are loaded in the project. You can show/hide layers and set other properties.
Toolsbars: Toolbars are shortcuts to execute frequently used commands. For example, there are special toolbars for vector and raster files, but also general ones for saving your project, etc. The toolbar contains, among other things, a list of all the commands you can use. The toolbar also contains the toolbox, which is used later in many of the wiki videos.

Map View: The map view is the central component of every GIS programme. This is where the geodata are displayed. The map view has a projection which does not always have to correspond to the projection of the layers.
Status bar: In the status bar you will find central information about the current map view. Here you can set the projection of the map view and the scale. You can read the coordinates of the mouse pointer and thus quickly find out the coordinates of points on the map. You can rotate your map view, e.g. if you want to create a map facing south.
Side Toolbar. You may see a side toolbar. This is another way to easily open vector and raster files in QGIS.
Locator bar. Here you can search for tools and layers. If you don’t know where to find a tool, you can try here.

Attention

If you see a * in the title bar, to the left of the name of your project, this means that the project has changes which are unsaved. Since QGIS can crash from time to time, make sure to save your project periodically to avoid losing progress.

Buttons and Shortcuts#

In QGIS, mouse control allows users to interact with the map canvas, enabling functions such as panning, zooming, and selecting features.

Hotkeys in the QGIS interface provide convenient shortcuts for various commands, enhancing efficiency and speeding up workflow. You can find all hotkeys below.

Navigation in the map view

Name	Shortcut	Description
Map pan	`Space`, `Page Up`, `Page Down` or the `Arrow Keys`	Move the map
Pan map to selection		Pans the map to the selected element
Zoom in	`Ctrl` + `Alt` + `+` or `mouse wheel`	Zoom into the map
Zoom out	`Ctrl` + `Alt` + `-` or `mouse wheel`	Zoom out of the map
Zoom full	`Ctrl` + `Shift` + `F`	Zoom to the selected element
Zoom to selection	`Ctrl` + `J`	Zoom to the selected element
Zoom to layer		Zoom to the selected layer
Zoom to native resolution		Zoom to the native resolution (100%)
Zoom last		Zoom to the last zoom
Zoom next		Zoom to the next zoom

Project managment

Name	Shortcut	Description
New Project	`Ctrl` + `N`	Create a new project
Open Project	`Ctrl` + `O`	Open an existing project
Save	`Ctrl` + `S`	Save the project
Save as…	`Ctrl` + `Shift` + `S`	Save the project as…
Properties	`Ctrl` + `Shift` + `P`	Open the project properties
New print layout	`Ctrl` + `P`	Opens the Dialog to create a new print layout
Search	`Ctrl` + `K`	Opens the search bar

Layer management

Name	Shortcut	Description
Data source manager	`Ctrl` + `L`	Add a new layer
New GeoPackage layer	`Ctrl` + `Shift` + `N`	Add a new GeoPackage Layer
Add vector layer	`Ctrl` + `Shift` + `V`	Add a new vector layer
Add raster layer	`Ctrl` + `Shift` + `R`	Add a new raster layer
Remove selected layer	`Ctrl` + `D`	Remove the selected layer
Toggle layers view	`Ctrl` + `1`	Toggle the layers view
Toggle browser view	`Ctrl` + `2`	Toggle the browser view

Analysis Tools

Name	Shortcut	Description
Identify Features	`Ctrl` + `Shift` + `I`	Identify features on the map view by clicking on them
Select feature		Select a feature by area or single click
Select feature by value	`F3`	Select features by value
Open Attribute table	`F6`	Open the Attribute table
Open Attribute table with selected features only	`Shift` + `F6`	Open the Attribute table with selected features only
Open Attribute table with visible features only	`Ctrl` + `F6`	Open the Attribute table with visible features only

Navigating on the Map Canvas#

Moving the map view#

To move on the map canvas with your mouse cursor you need to toggle the hand button.

You can always move on the map canvas with arrow keys on your keyboard.

Zooming in the map view#

The easiest way to zoom on Map Canvas is by scrolling.

Or with the hotkeys Ctrl + + and Ctrl + -

Another way is to use the zoom buttons in the toolbox panel.

Toolbox & Toolbars#

Basically, all the functionality, tools and applications of QGIS are organised in the Toolbox. Some Tools have their own toolbars which you can add to your QGIS interface.

Open Toolbox#

To open the Toolbox in QGIS click on the gearwheel button. Or click on Processing -> Toolbox

You can use the search bar to find specific tools.

Tip

There are cases when you want to do something in QGIS but do not know the exact tool. Sometimes it’s worth just looking for what you think the name of the tool might be.

Show and hide displays and toolbars#

There are toolbars and panels for many different tasks. To avoid an overcrowded interface it is smart to only activate specific toolbars or panels only when you really need them.

To add or remove toolbars from your interface click on View -> Toolbars -> Check or uncheck the toolboxes you want to add or remove.

To add or remove panels from your interface click on View -> Panels -> Check or uncheck the panels you want to add or remove.

Move and arrange toolbars#

At each toolbar there is a field of two dotted lines. If you move the mouse pointer over it until an arrow cross appears and then hold down the left mouse button, you can move the toolbar. This allows an individualised arrangement of your own tools. By compressing all toolbars into a few lines, the map view window can also be enlarged.

Save & Open QGIS Projects#

To save progress or to open an existing project in QGIS is very similar to programs like MS Word. However, there is one BIG difference. In QGIS, the geodata you work with is not saved in your QGIS project file. Instead, the project file only contains the file paths where the geodata were located at the time the project was last saved on the PC. If the location of this geodata is subsequently changed, the error message “handle unavailable layers” will appear when the project is opened again.

Good data organisation with a fixed and well-thought-out folder structure prevents such problems.

Warning

Always organize your data! Check out the Wiki article on Standard Folder Structure for more info.

Open Projects#

To open an existing QGIS project click on Project -> Open… -> Navigate to your project and open it.

Save Projects#

When you save for the first time: To save the QGIS project you are working on click on Project -> Save as…-> Navigate to the folder where you want to save the project -> Give the project a name -> Save
When saving your progress: To save progress in a project that was already saved somewhere on your computer:
- Click on Project -> Save.

Warning icons#

It can be that while working with QGIS, you come across orange warning icons. This indicates that you should pay attention. To understand what the warning icon means, hover over it with your mouse and explanatory text will appear. For example, in Fig. 14, the warning icon indicates that the units of measurements are degrees, which are not constant (the distance between 1⁰ of longitude is much greater at the equator than at the poles).

Where to find help#

Connect with us!

If you have more questions before or after the training or require assistance, do not hesitate to reach out to us by writing an email to gis-training-platform@heigit.org.

There is also a big and vibrant QGIS community online. If you are struggling with a specific function, or have questions on how to achieve GIS operations that are not covered on this platform, you can find help on dedicated QGIS forums:

QGIS user forum on stackexchange: https://gis.stackexchange.com/?tags=qgis
QGIS user groups: https://www.qgis.org/en/site/forusers/usergroups.html#qgis-usergroups
QGIS telegram channel: https://t.me/joinchat/Aq2V5RPoxYYhXqUPoxRWPQ

Additionally, there is a large amount of youtube tutorials, online guides and learning material for specific GIS-operations, so it is always a good idea to do a quick google search. Amongst others, the [QGIS documentation] (https://docs.qgis.org/3.34/en/docs/index.html) also offers Exercises and Training Material, as well as a Gentle Introduction to QGIS.

Name	Menu option	Shortcut	Description
Processing Toolbox		`Ctrl` + `Alt` + `T`	Opens the Processing Toolbox
Python Console		`Ctrl` + `Alt` + `P`	Opens the Python Console