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- Herausgeber: Packt Publishing
- Kategorie: Wissenschaft und neue Technologien
- Sprache: Englisch
Go beyond the basics and unleash the full power of QGIS 3.4 and 3.6 with practical, step-by-step examples
Key Features:
One-stop solution to all of your GIS needs Master QGIS by learning about database integration, and geoprocessing toolsLearn about the new and updated Processing toolbox and perform spatial analysis
Book Description:
QGIS is an open source solution to GIS and widely used by GIS professionals all over the world. It is the leading alternative to proprietary GIS software. Although QGIS is described as intuitive, it is also, by default, complex. Knowing which tools to use and how to apply them is essential to producing valuable deliverables on time.
Starting with a refresher on the QGIS basics and getting you acquainted with the latest QGIS 3.6 updates, this book will take you all the way through to teaching you how to create a spatial database and a GeoPackage. Next, you will learn how to style raster and vector data by choosing and managing different colors. The book will then focus on processing raster and vector data. You will be then taught advanced applications, such as creating and editing vector data. Along with that, you will also learn about the newly updated Processing Toolbox, which will help you develop the advanced data visualizations. The book will then explain to you the graphic modeler, how to create QGIS plugins with PyQGIS, and how to integrate Python analysis scripts with QGIS.
By the end of the book, you will understand how to work with all aspects of QGIS and will be ready to use it for any type of GIS work.
What you will learn:
Create and manage a spatial databaseGet to know advanced techniques to style GIS data Prepare both vector and raster data for processing Add heat maps, live layer effects, and labels to your maps Master LAStools and GRASS integration with the Processing Toolbox Edit and repair topological data errors Automate workflows with batch processing and the QGIS Graphical Modeler Integrate Python scripting into your data processing workflows Develop your own QGIS plugins
Who this book is for:
If you are a GIS professional, a consultant, a student, or perhaps a fast learner who wants to go beyond the basics of QGIS, then this book is for you. It will prepare you to realize the full potential of QGIS.
Shammunul Islam is a consulting spatial data scientist at the Institute of Remote Sensing, Jahangirnagar University, and a senior consultant at ERI, Bangladesh. He develops applications for automating geospatial and statistical analysis in different domains such as in the fields of the environment, climate, and socio-economy. He also consults as a survey statistician and provides corporate training on data science to businesses. Shammunul holds an MA in Climate and Society from Columbia University, an MA in development studies, and a BSc in statistics. Simon Miles is a GIS/web developer working for the Royal Borough of Windsor and Maidenhead, and has been working in the GIS industry since 2003. Both in the office and at home, he works using open source technologies. His main kit or stack includes QGIS, PostGIS, Python, GDAL, Leaflet, JavaScript, and PHP. His main focus presently is on digital delivery/transformation, chiefly through the consolidation of data, applications, and legacy systems, and replacing these with APIs and web applications. In 2013, Simon helped to establish the UK QGIS user group, which holds regional meetings two or three times a year. Kurt Menke, GISP, a former Albuquerque, New Mexico, USA-based archaeologist, has an MS in geography from the University of New Mexico in 2000. He has founded Bird's Eye View to apply his expertise with GIS technology toward ecological conservation. His other focus areas are public health and education. He is an avid GIS proponent since he began writing MapServer applications in 2002. He has authored Discover QGIS. In 2015, Kurt was voted in as an OSGeo Charter Member. He is a FOSS4G educator and a co-author of the GeoAcademy. In 2015, he was awarded the Global Educator of the Year Team Award by GeoForAll as part of the GeoAcademy team. He authors an award-winning blog on FOSS4G technologies and their use in community health mapping. Richard Smith Jr., GISP, is an assistant professor of geographic information science in the School of Engineering and Computing Sciences at Texas A&M University – Corpus Christi. He has a Ph.D. in geography from the University of Georgia and holds an MSc in computer science and a BSc in geographic information science from Texas A&M University-Corpus Christi. Richard actively researches in cartography, systems integration, and the use of geospatial technology for disaster response. He is an advocate for FOSS4G and building a FOSS4G curriculum. He is also one of the co-authors of the FOSS4G Academy. Luigi Pirelli is a QGIS core developer and software analyst with a degree in computer science from Bari University. He worked for 15 years in the Satellite Ground Segment and Direct Ingestion for the European Space Agency. He is also involved in GFOSS world, contributing in QGIS, GRASS, & MapServer core, and developing and maintaining many QGIS plugins. Luigi is the founder of the OSGEO Italian local GFOSS chapter. He has taught PyQGIS, delivering training from basic to advanced levels, and supporting companies to develop their own specific QGIS plugins. He founded a local hackerspace group. Bricolabs.cc. He likes training groups on conflict resolution. Other than this book, he has also contributed to the Lonely Planet guide Cycling Italy. John Van Hoesen, GISP, is an associate professor of geology and environmental studies at Green Mountain College in rural west-central Vermont, USA. He earned an MS and a Ph.D. in geology from the University of Nevada, Las Vegas, in 2000 and 2003. He is a certified GISP with a broad background in the geosciences and has used some flavor of GIS to evaluate and explore geological processes and environmental issues since 1997. John has used and taught graduate, undergraduate, and continuing education courses using some variants of FOSS GIS since 2003.
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Mastering Geospatial Development with QGIS 3.x Third Edition
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First published: March 2015 Second edition: September 2016 Third edition: March 2019
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Contributors
About the authors
Shammunul Islam is a consulting spatial data scientist at the Institute of Remote Sensing, Jahangirnagar University, and a senior consultant at ERI, Bangladesh. He develops applications for automating geospatial and statistical analysis in different domains such as in the fields of the environment, climate, and socio-economy. He also consults as a survey statistician and provides corporate training on data science to businesses. Shammunul holds an MA in Climate and Society from Columbia University, an MA in development studies, and a BSc in statistics.
Simon Miles is a GIS/web developer working for the Royal Borough of Windsor and Maidenhead, and has been working in the GIS industry since 2003. Both in the office and at home, he works using open source technologies. His main kit or stack includes QGIS, PostGIS, Python, GDAL, Leaflet, JavaScript, and PHP. His main focus presently is on digital delivery/transformation, chiefly through the consolidation of data, applications, and legacy systems, and replacing these with APIs and web applications. In 2013, Simon helped to establish the UK QGIS user group, which holds regional meetings two or three times a year.
Kurt Menke, GISP, a former Albuquerque, New Mexico, USA-based archaeologist, has an MS in geography from the University of New Mexico in 2000. He has founded Bird's Eye View to apply his expertise with GIS technology toward ecological conservation. His other focus areas are public health and education. He is an avid GIS proponent since he began writing MapServer applications in 2002. He has authored Discover QGIS. In 2015, Kurt was voted in as an OSGeo Charter Member. He is a FOSS4G educator and a co-author of the GeoAcademy. In 2015, he was awarded the Global Educator of the Year Team Award by GeoForAll as part of the GeoAcademy team. He authors an award-winning blog on FOSS4G technologies and their use in community health mapping.
Richard Smith Jr., GISP, is an assistant professor of geographic information science in the School of Engineering and Computing Sciences at Texas A&M University – Corpus Christi. He has a Ph.D. in geography from the University of Georgia and holds an MSc in computer science and a BSc in geographic information science from Texas A&M University-Corpus Christi. Richard actively researches in cartography, systems integration, and the use of geospatial technology for disaster response. He is an advocate for FOSS4G and building a FOSS4G curriculum. He is also one of the co-authors of the FOSS4G Academy.
Luigi Pirelli is a QGIS core developer and software analyst with a degree in computer science from Bari University. He worked for 15 years in the Satellite Ground Segment and Direct Ingestion for the European Space Agency. He is also involved in GFOSS world, contributing in QGIS, GRASS, & MapServer core, and developing and maintaining many QGIS plugins. Luigi is the founder of the OSGEO Italian local GFOSS chapter. He has taught PyQGIS, delivering training from basic to advanced levels, and supporting companies to develop their own specific QGIS plugins. He founded a local hackerspace group. Bricolabs.cc. He likes training groups on conflict resolution. Other than this book, he has also contributed to the Lonely Planet guide Cycling Italy.
John Van Hoesen, GISP, is an associate professor of geology and environmental studies at Green Mountain College in rural west-central Vermont, USA. He earned an MS and a Ph.D. in geology from the University of Nevada, Las Vegas, in 2000 and 2003. He is a certified GISP with a broad background in the geosciences and has used some flavor of GIS to evaluate and explore geological processes and environmental issues since 1997. John has used and taught graduate, undergraduate, and continuing education courses using some variants of FOSS GIS since 2003.
About the reviewers
Giuseppe De Marco, a Ferentino based agricultural engineer, has a Bachelor's in agriculture from the University of Pisa. He started programming at an early age. He developed deep interests in geography and GIS during his bachelor’s. He then got introduced to GRASS and QGIS while working with Eris commercial products. Since QGIS 1.7.4, he has been developing plugins for it, In 2008, he partnered with his 2 colleagues and started Pienocampo (open field), a website that hosts plugins made by him which are also hosted on OGIS official repository. He likes studying geography, surveying, tree risk assessment, landscaping, bioengineering, and farm consulting. He also likes imparting knowledge on how to use QGIs and other open source software.
Chima Obi is the lead geospatial analyst at AGERPoint Inc. He has over 4 years of experience as a geospatial analyst. His specialty includes processing LIDAR data and feature extraction from raster/imagery data utilizing Python and R programing, as well as exploring other open source geospatial tools. He got his Bachelors in soil science from the Federal University of Technology, Owerri, Nigeria in 2010. He moved to the United States where he obtained his master’s degree in environmental science and got a certification in Geospatial information systems in 2016. Prior to working at AGERPoint, he worked as a geospatial analyst at West Virginia District of Highways in 2015 and 2016.
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Table of Contents
Title Page
Copyright and Credits
Mastering Geospatial Development with QGIS 3.x Third Edition
About Packt
Why subscribe?
Packt.com
Contributors
About the authors
About the reviewers
Packt is searching for authors like you
Preface
Who this book is for
What this book covers
To get the most out of this book
Download the example code files
Download the color images
Conventions used
Get in touch
Reviews
Section 1: Introduction
A Refreshing Look at QGIS
Release schedules
QGIS downloading and installation
Installing QGIS on Windows
Installing QGIS on macOS
Installing QGIS on Ubuntu Linux
Installing QGIS only
Installing QGIS and other FOSSGIS packages
QGIS on Android
Installing QGIS on a Chromebook
QGIS in a browser
What's new?
A tour of QGIS
Familiarizing yourself with QGIS Desktop
Loading data into QGIS Desktop
Loading vector data
Loading raster data
Loading databases
Loading web services
Working with CRS
Working with tables
Creating table joins
Editing data
Snapping
Styling vector data
Styling raster data
Blending modes
Composing maps
Adding functionality with plugins
Custom QGIS variables
Summary
Section 2: Getting Started
Styling Raster and Vector Data
Choosing and managing colors
Knowing color picker components
Changeable panels in the color picker
Color ramp
Color wheel
Color swatches
Color sampler
Color picker components in the Layers panel
Managing color ramps
Managing the QGIS color ramp collection
Renaming a color ramp
Removing a color ramp
Exporting a color ramp
Importing a color ramp
Adding a color ramp
Adding a gradient color ramp
Adding a random color ramp
Adding a ColorBrewer color ramp
Adding a cpt-city color ramp
Editing a color ramp
Styling singleband rasters
Paletted raster band rendering 
Singleband gray raster band rendering
Singleband pseudocolor raster band rendering
Singleband pseudocolor interpolations
Styling multiband rasters
Raster color rendering
Raster resampling
Styling vectors
Single-symbol vector styling
Categorized vector styling
Graduated vector styling
Rule-based vector styling
Point-displacement vector styling
Point cluster vector styling
Inverted polygons vector styling
Heatmap vector styling
2.5 D vector styling
Vector layer rendering
Layer transparency
Layer blending mode
Feature blending mode
Control feature rendering order
Using diagrams to display thematic data
Parameters that are common to all diagram types
Diagram size parameters
Diagram placement parameters
Adding attributes to diagrams
Creating a pie chart diagram
Creating a text diagram
Creating a histogram chart diagram
Saving, loading, and setting default styles
Saving a style
Loading a style
Setting and restoring a default style
Adding and renaming styles in the current QGIS project
Summary
Creating Spatial Databases
Fundamental database concepts
Describing database tables
Knowing about table relationships
Reviewing the basics of the structured query language
Creating a spatial database
Connecting to a GeoPackage
Importing data into a GeoPackage
Importing a vector file
Importing a layer from map canvas
Working with tables
Creating a new table within an existing GeoPackage
Renaming a table
Editing an existing table field/column
Deleting a GeoPackage table 
Exporting tables out of a GeoPackage
Creating queries and views
Using select statements
Creating a spatial view
Dropping a spatial view
Summary
Preparing Vector Data for Processing
Merging vectors
Converting vector geometries
Creating polygon centroids
Converting lines into polygons
Converting polygons into lines
Creating polygons surrounding individual points
Voronoi polygons
Delaunay triangulation
Extracting nodes (vertices)
Simplifying and densifying features
Converting between multipart and singleparts features
Adding geometry columns to an attribute table
Using basic vector Geoprocessing Tools
Spatial overlay tools
Using the Clip and Difference tools
Using the Intersect and Symmetrical Difference tools
Overlaying polygon layers with Union
Creating buffers
Generating convex hulls
Dissolving features
Defining coordinate reference systems
Understanding the PROJ.4 definition format
Defining a new custom coordinate reference system
Setting Definitions
Viewing a statistical summary of vector layers
Advanced field calculations
Exploring the field calculator interface
Writing advanced field calculations
Calculating and formatting current date
Calculating with geometry
Operators
Conditions
Conditionals
Summary
Preparing Raster Data for Processing
Merging rasters
About converting raster files
Translating
Exporting to a raster
Exporting a raster to a GeoPackage
Clipping a raster
Converting rasters into vectors
Converting from vector to raster (rasterize)
Reclassifying rasters 
Summary
Section 3: Diving Deeper
Advanced Data Creation and Editing
What's new in editing?
CAD-style digitizing tools
Adding a circle
Adding a circle from two points
Adding a circle from three points
Adding a rectangle
Adding a rectangle from Extent
Adding a rectangle from its center point
Adding a rectangle from three points
Adding a regular polygon
Adding a regular polygon from the center and from a corner
Adding a regular polygon from two points
Vertex tool
Creating points from coordinate data
Mapping well-known text representations of geometry
Geocoding address-based data
How address Geocoding works
The first example – Geocoding using web services
The second example – Geocoding using local street network data
Georeferencing imagery
Understanding ground control points
Using the Georeferencer GDAL plugin
The first example – Georeferencing using a second dataset
Getting started
Entering ground control points
Transformation settings
Completing the operation
The second example – Georeferencing using a point file
Checking the topology of vector data
Installing the topology checker
Topological rules
Rules for point features
Rules for line features
Rules for polygon features
Using the topology checker
Repairing topological errors via topological editing
Example 1 – Resolving duplicate geometries
Example 2 – Repairing overlaps
Setting the editing parameters
Repairing an overlap between polygons
Example 3 – Repairing a gap between polygons
Summary
Advanced Data Visualization
Using live layer effects
Creating beautiful effects with inverted polygon shapeburst fills
Creating coastal vignettes
Studying area mask
Using the 2.5D renderer
Creating 3D views 
Creating an Atlas
Basic Atlas configuration
Dynamic titles
Dynamic legends
Highlighting the coverage feature
The power of geometry generators
Working with the Data Plotly plugin
Summary
Section 4: Becoming a Master
The Processing Toolbox
Introducing the Processing Toolbox
What's new in the Processing Toolbox?
Configuring the Processing Toolbox
Viewing the Processing Toolbox
Running algorithms in the Processing Toolbox
Using the Processing Toolbox
Performing raster analysis with GRASS
Calculating shaded relief
Calculating least-cost path
Calculating slope using r.slope
Reclassifying the new slope raster and the land use raster
Combining reclassified slope and land use layers
Calculating the cumulative cost raster using r.cost
Calculating the cost path using LCP
Evaluating a viewshed
Clipping elevation to the boundary of the park using GDAL
Calculating viewsheds for towers using r.viewshed
Combining viewsheds using r.mapcalc.simple
Performing analysis using SAGA
Evaluating a habitat
Calculating elevation ranges using the SAGA Raster calculator
Clipping land use to the park boundary using Clip grid with polygon
Querying land use for only surface water using the SAGA Raster calculator
Finding proximity to surface water using GDAL Proximity
Querying the proximity for 1,000 meters of water using the GDAL Raster calculator
Reclassifying land use using the Reclassify grid values tool
Combining raster layers using the SAGA Raster calculator
Exploring hydrologic analysis with SAGA
Removing pits from the DEM
Deriving streams
Selecting the streams
Delineating the streams
Calculating the upstream area above Fort Klamath
Summary
Automating Workflows with the Graphical Modeler
Introducing the graphical modeler
Opening the graphical modeler
Configuring the modeler and naming a model
Working with your model
Adding data inputs to your model
Adding algorithms to your model
Running a model
Editing a model
Documenting a model
Saving, loading, and exporting models
Executing model algorithms iteratively
Nesting models
Using batch processing with models
Converting a model into a Python script
Summary
Creating QGIS Plugins with PyQGIS and Problem Solving
Webography - where to get API information and PyQGIS help
PyQGIS cookbook
API documentation
The QGIS community, mailing lists, and IRC channel
Mailing lists
IRC channel
The Stack Exchange community
Sharing your knowledge and reporting issues
The Python Console
Getting sample data
My first PyQGIS code snippet
My second PyQGIS code snippet - looping the layer features
Exploring iface and QGis
Exploring a QGIS API in the Python Console
Creating a plugin structure with Plugin Builder
Installing Plugin Builder
Locating plugins
Creating my first Python plugin - plugin_first
Setting mandatory plugin parameters
Setting optional plugin parameters
Generating the plugin code
Compiling the icon resource
Plugin file structure - where and what to customize
Exploring main plugin files
Plugin Builder-generated files
A simple plugin example
Adding basic logic to TestPlugin
Modifying the layout with Qt Designer
Adding two pull-down menus
Modifying GUI logic
Modifying plugin logic
Classifying layers
Populating the combo box
Understanding self
Showing and running the dialog
Some improvements
More detail of the code
Setting up a debugging environment
What is a debugger?
Installing Aptana
Setting up PYTHONPATH
Starting the Pydevd server
Connecting QGIS to the Pydevd server
Connecting using the Remote Debug QGIS plugin
Debugging session example
Creating a PyDev project for TestPlugin
Adding breakpoints
Debugging in action
Summary
PyQGIS Scripting
Where to learn Python basics
Tabs or spaces – make your choice!
How to load layers
How to manage rasters
Exploring QgsRasterLayer
Visualizing the layer
Managing vector files
Managing database vectors
Vector structure
The basic vector methods
Describing the vector structure
Describing the header
Describing the rows
Exploring QgsGeometry
Iterating over features
Describing iterators
Editing features
Updating the canvas and symbology
Editing through QgsVectorDataProvider
Changing a feature's geometry
Changing a feature's attributes
Deleting a feature
Adding a feature
Editing using QgsVectorLayer
Discovering the QgsVectorLayerEditBuffer class
Changing a feature's geometry
Changing a feature's attributes
Adding and removing a feature
Running Processing Toolbox algorithms
Listing all available algorithms
Getting algorithm information
Running algorithms from the console
Running your own processing script
Creating a test Processing Toolbox script
Running the script
Interacting with the map canvas
Getting the map canvas
Explaining Map Tools
Setting the current Map Tool
Getting point-click values
Getting the current Map Tool
Creating a new Map Tool
Creating a map canvas event handler
Creating a Map Tool event handler
Setting up the new Map Tool
Using point-click values
Exploring the QgsRubberBand class
Summary
Other Books You May Enjoy
Leave a review - let other readers know what you think
Preface
Welcome to Mastering Geospatial Development with QGIS 3.x, Third Edition. With the release of QGIS 3, QGIS has broken new ground in enhancing the user experience with new features – this book aims to introduce you to these features. Throughout 11 chapters, you will explore QGIS 3.4 and QGIS 3.6, with particular emphasis on data processing, creation, editing, and visualization, with data stored in databases such as Spatialite, GeoPackages, and PostGIS.
Who this book is for
If you are a GIS professional, a consultant, a student, or perhaps a fast learner who wants to go beyond the basics of QGIS, then this book is for you. It will prepare you to realize the full potential of QGIS.
What this book covers
Chapter 1, A Refreshing Look at QGIS, covers those features that were new to QGIS in version 3.0 and those that have now been introduced at version 3.4 and version 3.6.
Chapter 2, Styling Raster and Vector Data, explores styling raster and vector data for display. First, color selection and color ramp management are covered. Next, single-band and multi-band raster data is styled using custom color ramps and blending modes. Then, complex vector styles and vector layer rendering are covered.
Chapter 3, Creating Spatial Databases, introduces the user to the use of databases that are locally stored in file directories, such as Spatialite and GeoPackages. Users will learn how to create their own local database, as well as how to add data into it from scratch, or import existing data.
Chapter 4, Preparing Vector Data for Processing, introduces you to the tools and functions that come as standard within QGIS for working with vector datasets.
Chapter 5, Preparing Raster Data for Processing, introduces you to the tools and functions that come as standard within QGIS for working with rasters.
Chapter 6, Advanced Data Creation and Editing, provides advanced ways to create vector data. As there is a great deal of data in tabular format, this chapter will cover mapping coordinates and addresses from tables. Next, georeferencing of imagery into a target coordinate reference system will be covered. The final portion of the chapter will cover testing topological relationships in vector data and correcting any errors via topological editing.
Chapter 7, Advanced Data Visualization, covers the powerful data visualization tools found only in QGIS.
Chapter 8, The Processing Toolbox, begins with an explanation and exploration of the QGIS Processing Toolbox. Various algorithms and tools, available in the toolbox, will be used to complete common spatial analyses and geoprocessing tasks for both raster and vector formats. To illustrate how these processing tools might be applied to real-world questions, two hypothetical scenarios are illustrated, relying heavily on the GRASS and SAGA tools.
Chapter 9, Automating Workflows with the Graphical Modeler, covers the purpose and use of the graphical modeler to automate analysis workflows. In this chapter, you will develop an automated tool/model that can be added to the Processing Toolbox.
Chapter 10, Creating QGIS Plugins with PyQGIS and Problem Solving, covers the foundational information required to create a Python plugin for QGIS. Information about the API and PyQGIS help will be covered first, followed by an introduction to the iface and QGis classes. Next, the steps required to create and structure a plugin will be covered. The chapter will be wrapped up after providing you with information on creating graphical user interfaces and setting up debugging environments to debug code easily.
Chapter 11, PyQGIS Scripting, covers topics on integrating Python analysis scripts with QGIS outside of the Processing Toolbox. Layer loading and management are first covered, followed by an exploration of the vector data structure. Next, the programmatic launching of other tools and external programs are covered. Lastly, the QGIS map canvas is covered with respect to how a script can interact with the map canvas and layers within.
To get the most out of this book
You should have good knowledge of Python and QGIS.
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Section 1: Introduction
QGIS 3 is the first major new release of QGIS in several years. This section reviews what major changes will be treated as assumed knowledge for the remainder of the book.
This section contains the following chapter:
Chapter 1
,
A Refreshing Look at QGIS
A Refreshing Look at QGIS
In this chapter, we will review the basic functionality of QGIS and explore some of the new features of versions starting from 3.4. If you need a refresher on QGIS or a quickstart guide to QGIS, you should read this chapter. The topics we will cover in this chapter are as follows:
Downloading QGIS and its installation
The QGIS graphical user interface
Loading data
Working with
coordinate reference systems
(
CRS
)
Working with tables
Editing data
Styling data
Composing a map
Finding and installing plugins
QGIS is a volunteer-led development project licensed under the GNU General Public License, and was started by Gary Sherman in 2002. The project was incubated with the Open Source Geospatial Foundation (OSGeo) in 2007, with QGIS 1.0 being released in 2009. The continued development of QGIS is supported by an active and vibrant community from around the world. Many people assume that they can only help with the development of QGIS if they can perform computer programming, but this is false! QGIS has many community members that write documentation, test the program for bugs, translate documents, answer forum questions, and provide financial support. QGIS user groups exist as well, aiming to bring people together to share experiences of QGIS. It is easy to get involved, and the authors encourage you to consider contributing. Learn about how to get involved at http://qgis.org/en/site/getinvolved/.
Release schedules
Currently, a new version of QGIS is released around every four months. The version released each spring is designated as a long-term release (LTR). This means it will be supported for one calendar year. Each quarter, a new stable version is released and bug fixes applied to the LTR. The LTR is recommended for production environments since it has a slower release cycle. At the time of writing, QGIS 3.4.5 is the current LTR, with version 3.6 available for download.
QGIS downloading and installation
QGIS can be installed on Windows, macOS, Unix, Linux, and Android operating systems, making it a very flexible software package. Both the binary installers and source code can be downloaded from download.qgis.org. In this section, we will briefly cover how to install QGIS on Windows, macOS, and Ubuntu Linux. For the most up-to-date installation instructions, refer to the QGIS website.
Installing QGIS on Windows
On the QGIS website, download the correct version of QGIS for your Windows machine. Downloadable executable files come in 32-bit and 64-bit flavors. We recommend downloading the latest release as advertised on the QGIS website download page.
For Windows, there are two installation options, which are as follows:
QGIS Standalone Installer
: The standalone installer installs the binary version of QGIS and the
Geographic Resource Analysis Support System
(
GRASS
) using a standard Windows installation tool. You should choose this option if you want an easy installation experience of QGIS. This is also the ideal installation method for organizations or businesses wishing to deploy QGIS to multiple users.
OSGeo4W Network Installer
: This provides you with the opportunity to download either the binary or source code version of QGIS, as well as experimental releases of QGIS. Additionally, the OSGeo4W installer allows you to install other open source tools and their dependencies.
If you are unsure on how to install QGIS, the QGIS website contains details on how to do this.
Installing QGIS on macOS
The QGIS website provides download mac installer packages for macOS, that contain readme files for the installation of QGIS. Documentation and support for QGIS on macOS has greatly improved, and while it is beyond the scope of this chapter to detail the install process and document any possible issues that might incur during installation, the GIS Stack Exchange (https://gis.stackexchange.com/) is a great refresh resource.
Installing QGIS on Ubuntu Linux
There are two options when installing QGIS on Ubuntu: installing QGIS only, or installing QGIS as well as other Free and Open Source Software for Geographical Information Systems (FOSSGIS) packages. Either of these methods requires the use of the command line, sudo rights, and the apt-get package manager.
Installing QGIS only
Depending on whether you want to install a stable release or an experimental release, you will need to add the appropriate repository to the /etc/apt/sources.list file.
With sudo access, edit /etc/apt/sources.list and add the following line to install the current stable release or the current release source code, respectively:
deb http://qgis.org/debian trusty main deb-src http://qgis.org.debian trusty main
Depending on the release version of Ubuntu you are using, you will need to specify the release name as trusty, saucy, or precise. For the latest list of QGIS releases for Ubuntu versions, visit download.qgis.org.
With the appropriate repository added, you can proceed with the QGIS installation by running the following commands:
sudo apt-get update sudo apt-get install qgis python-qgis
To install the GRASS plugin (recommended), install the optional package by running this command:
sudo apt-get install qgis-plugin-grass
Installing QGIS and other FOSSGIS packages
The ubuntugis project installs QGIS and other FOSSGIS packages, such as GRASS on Ubuntu. To install the ubuntugis package, remove the http://qgis.org/debian lines from the /etc/apt/sources.list file and run the following commands:
sudo apt-get install python-software-properties sudo add-apt-repository ppa:ubuntugis/ubuntugis-unstable sudo apt-get update sudo apt-get install qgis python-qgis qgis-plugin-grass
QGIS on Android
At the time of writing, there is really only one Android QGIS application available on Google Play, called QField, developed by OPENGIS.ch from Switzerland. Users of QGIS can save their projects to their Android device and then reopen them in QField. The application comes with Geolocation capabilities, data editing, and photos captured, to name just a few of its features.
While QField may currently (at the time of writing) be one of the main Android QGIS applications available, the underlying architecture of QGIS, namely QT5 and Python3, mean that development and deployment of user-created Android applications is not far away, thanks to crowdfunding opportunities organized by such companies as Lutra Consultancy and North Road.
Installing QGIS on a Chromebook
It is possible to install the Ubuntu Linux operating system on a Chromebook via Crouton (https://chromebook.guide/crouton/). This essentially creates a dual boot environment allowing you to switch between the Chrome OS and Ubuntu very quickly with some keyboard strokes. Once Crouton is set up, QGIS can be installed via the preceding Ubuntu QGIS install processes.
QGIS in a browser
Using the RollApp website (https://www.rollapp.com), you can access QGIS, plus a range of other open source software in your web browser. This means that for Chromebook and iPad (for example), users can access QGIS without physically installing any software or making system configuration changes. RollApp is designed around using cloud base storage, such as Google Drive, Dropbox, and Box. This makes sharing data and projects very easy.
What's new?
With the release of version 3 of QGIS comes a host of new features and tools—far too many to document here, but if you are interested, take a look at http://changelog.qgis.org/en/qgis/version/3.4-LTR. For the new addition to QGIS 3.6, have a look at this http://changelog.qgis.org/en/qgis/version/3.6.0/. The biggest shift in QGIS 3.x is the migration from Python 2 to 3, which has extended the functionality to run scripts, processes, and tasks. Further to this, the underlying application used to build the QGIS interface, called Qt as of version 3.x, runs off Qt5.
To highlight perhaps just a few of these new features, note the following:
Data Source Manager
: The
Data Source Manager
(accessed via or
Ctrl
+
L
) i
s perhaps the most notable visual change of 3.4, as it is presented as the default tool to accessing data to load onto the
Map
Canvas:
Opening layers over HTTP(s), FTP, and cloud storage
: Sharing and accessing data through QGIS has gotten a whole lot easier with 3.x series. No longer does data need to be stored on a local or networked drive; instead, data can be accessed through HTTP(s), FTP, or via cloud storage providers such as Google Drive. There are now really no limits as to how QGIS can fetch, receive, and display GIS data.
Filters
:
In previous versions of QGIS, it has been difficult to know which layers have had filters applied to them.
In version 3.4, this has been remedied with a filter icon being placed on all layers that have filters applied. A user can click on the filter icon to gain quick access to the query builder.
Import geotagged photos
: Photos that have been geotagged (which is commonly set as a default function on most modern smartphones) can now be uploaded onto the Map Canvas and represented as a point value. The metadata associated with the photo can also be accessed.
Save project to Postgres
:
This is a truly remarkable step forward for QGIS. The ability to save a QGIS project to a database table adds a new level of security, but also accessibility, to QGIS. It is now possible to simply send someone postgres connection details and, once added into QGIS, this will allow the user to access permission-based projects and layers (tables) stored on the database. This means that no data, no projects, and indeed, no physical files need to be handled by a user to access QGIS data.
Locator Search Bar
:
Located in the bottom left, below the panels, is the
Locator Search
bar that is a quick finder for processes, tools, and can even be configured to search layers.
3D and mesh
: There has been significant investment in 3D in version 3. 3D views of data can now be seen in its own
Map View
, which runs in parallel to the main Map Canvas. Mesh data can now be loaded into QGIS and viewed in 3D.
Print Layouts
:
Other than a change of name from Print Compose to Print Layouts, QGIS 3.4 brings some new elements to the Print window, such as the ability to add 3D views. There have been changes to the
Item Properties
to increase overall functionality.
Identity tool for mesh layers:
In QGIS 3.6, we can use
Identify
tool with mesh layer. We can see the value of both scalar and vector component
A tour of QGIS
QGIS is composed of two programs: QGIS Desktop and QGIS Browser. Desktop is used for managing, displaying, analyzing, and styling data. Browser is used for managing and previewing data. This section will give you a brief tour of the graphical user interface components of both QGIS Desktop and QGIS Browser.
Familiarizing yourself with QGIS Desktop
The QGIS interface is divided into four interface types: Menu Bar, Toolbars, Panel, and Map Canvas. The following screenshot shows QGIS Desktop with all four interface types displayed:
The Map Canvas shows the styled data added to the QGIS project. The Menu Bar, displayed across the top, provides access to most of the QGIS functions. The Toolbars provide quick access to QGIS core functionality. The Toolbars can be arranged to either float independently or dock at the top, bottom, left, or right sides of the application—equally, toolbar ideas can be removed from the screen via Settings | Interface Customization.
The panels, such as Browser and Layers, provide a variety of functionality and can be arranged to either float independently or dock above, below, right, or left of the map display or side by side as tabs.
QGIS Desktop offers a number of customization options. You can toggle the visibility of toolbars by navigating to View | Toolbars, or by right-clicking on the Menu Bar and then enabling the Toolbars button, which will open a context menu allowing you to toggle the toolbar and panel visibility. You can assign shortcut keys to operations by navigating to Settings | Configure shortcuts. You can also change application options, such as interface language and rendering options, by navigating to Settings | Options.
Loading data into QGIS Desktop
One strength of QGIS is its ability to load a large number of data types. In this section, we will cover loading various types of data into QGIS Desktop.
In general, data can be loaded in a number of ways. The main way, which will be covered in detail in this section, is to use the Data Source Manager.
Alternatively, using the Browser panel, navigate to the data you wish to load, and then either drag the data onto the Map Canvas or right-mouse click on it and choose Add Selected Layer(s) to canvas.
Under Settings | Add Layer from the main Menu.
Also, you can drag and drop data/files from your native operating systems file manager. Even ZIP files that contain .shp files can be added to the Map Canvas in this way.
Loading vector data
To load vector files using the Data Source Manager, click on the Open Data Source Manager icon , or press Ctrl + L. From the list of layer types on the left, choose Vector. You now have the option to load a Vector file for a number of Source type options:
The source type contains four options: File, Directory, Database, and Protocol: HTTP(S), cloud, etc. When you choose a source type, the source interface will change to display the appropriate options. Let's take a moment to discuss what types of data these four source types can load:
File
: This can load flat files that are stored on disk. The commonly used flat file types are as follows:
GeoPackage (
.gpkg
)
ESRI shapefile (
.shp
)
GeoJSON (
.geojson
)
Geography Markup Language (
.gml
)
AutoCAD DXF (
.dxf
)
Comma-separated values (
.csv
)
GPS eXchange Format (
.gpx
)
Keyhole Markup Language (
.kml
)
SQLite/SpatiaLite (
.sqlite
/
.db
)
Directory
: This can load data stored on disk that is encased in a directory. The commonly used directory types are as follows:
U.S. Census TIGER/Line
Arc/Info Binary Coverage
Database
: This can load databases that are stored on disk or those available through service connections. The commonly used database types are as follows:
ODBC
ESRI Personal GeoDatabase
MSSQL
MySQL
PostgreSQL
Protocol
: This can load protocols that are available at a specific URL. In QGIS 3.4, these protocols have been extended to include calls to
HTTP/
HTTPS/
FTP
,
AWS S3
, and
Google Cloud Storage
, adding to the previous
GeoJSON
and
CouchDB
options:
Loading raster data
To load raster files using the Data Source Manager, click on the Open Data Source Manager icon , or press Ctrl + L. From the list of layer types on the left, choose Raster.
You now have the option to load a raster file for File or Protocol: HTTP(S), cloud, etc. (much like Vector):
The commonly used raster types supported by GDAL are as follows:
ArcInfo ASCII Grid (
.asc
)
Erdas Imagine (
.img
)
GeoTIFF (
.tif
/
.tiff
)
JPEG/JPEG-2000 (
.jpg
or
.jpeg
/
.jp2
or
.j2k
)
Portable Network Graphics (
.png
)
RasterLite (
.sqlite
)
USGS Optional ASCII DEM (
.dem
)
Loading databases
QGIS supports PostGIS, SpatiaLite, Microsoft SQL Server, and Oracle databases. Regardless of the type of database you wish to load, the loading sequence is very similar. Therefore, instead of covering specific examples, the general sequence will be covered.
To create a new database connection using the Data Source Manager, perform the following:
Click on the
Open
Data Source Manager
icon
or press
Ctrl
+
L
On the left, choose the database you want to connect to, and, in the connection window, click on the
New
button
Add all the connection details required
To add a layer once a connection has been established, perform the following:
Click on the
Open Data Source Manager
icon
Click on
Connect
When connected successfully, you will be presented with a list of layers that can be added to the Map Canvas. An alternative and perhaps better method for loading data on the Map Canvas is to use the Browser panel once you have created the new database connection. Using the Browser panel gives the user a cleaner overview of the layers and tables that can be added to the Map Canvas.
Loading web services
QGIS supports the loading of OGC-compliant web services such as WMS/WMTS, WCS, and WFS. Loading a web service is similar to loading a database service in that you must first set up the connection to the service, and then connect to the service to choose which layers to add to the Map Canvas.
As an example, to add a WMS service, click on the Open Data Source Manager icon or press Ctrl + L, and, on the left-hand side of the window, click on WMS/WMTS.
Click on the New button and give the new connection details a name (this is a free text friend, so the name can be anything you wish) and then add in the URL of the WMS/WMTS. Once completed, click on OK.
As with viewing data from databases in the previous section, to view the data available via the connection that you have established via the Data Source Manager, it is best to access the data via the browser panel.
Working with CRS
When working with spatial data, it is important that a CRS is assigned to the data and the QGIS project. To view the CRS for the QGIS project, click on Properties under Project, and choose the CRS tab.
It is recommended that all data added to a QGIS project be projected into the same CRS as the QGIS project. However, if this is not possible or convenient, QGIS can project layers on the fly to the project's CRS.
