Qgis is an open source gis software
QGIS is a free and open-source cross-platform desktop geographic information system (GIS) application that supports viewing, editing, printing, and analysis of geospatial data.
QGIS functions as geographic information system (GIS) software, allowing users to analyze and edit spatial information, in addition to composing and exporting graphical maps. QGIS supports raster, vector and mesh layers. Vector data is stored as either point, line, or polygon features. Multiple formats of raster images are supported, and the software can georeference images.
QGIS supports shapefiles, personal geodatabases, dxf, MapInfo, PostGIS, and other industry-standard formats. Web services, including Web Map Service and Web Feature Service, are also supported to allow use of data from external sources.
QGIS integrates with other open-source GIS packages, including PostGIS, GRASS GIS, and MapServer. Plugins written in Python or C++ extend QGIS’s capabilities. Plugins can geocode using the Google Geocoding API, perform geoprocessing functions similar to those of the standard tools found in ArcGIS, and interface with PostgreSQL/PostGIS, SpatiaLite and MySQL databases.
QGIS can also be used with SAGA GIS and Kosmo.
Gary Sherman began development of Quantum GIS in early 2002, and it became an incubator project of the Open Source Geospatial Foundation in 2007. Version 1.0 was released in January 2009.
In 2013, along with release of version 2.0 the name was officially changed from Quantum GIS to QGIS to avoid confusion as both names had been used in parallel.)
Written mainly in C++, QGIS makes extensive use of the Qt library. In addition to Qt, required dependencies of QGIS include GEOS and SQLite. GDAL, GRASS GIS, PostGIS, and PostgreSQL are also recommended, as they provide access to additional data formats.
A screenshot from QGIS-Android in 2014.
As of 2017 , QGIS is available for multiple operating systems including Mac OS X, Linux, Unix, and Microsoft Windows. A mobile version of QGIS was under development for Android as of 2014 .
QGIS can also be used as a graphical user interface to GRASS. QGIS has a small install footprint on the host file system compared to commercial GISs and generally requires less RAM and processing power; hence it can be used on older hardware or running simultaneously with other applications where CPU power may be limited.
QGIS is maintained by volunteer developers who regularly release updates and bug fixes. As of 2012 , developers have translated QGIS into 48 languages and the application is used internationally in academic and professional environments. Several companies offer support and feature development services.
QGIS can display multiple layers containing different sources or depictions of sources.
Screenshot of Print Composer
In order to prepare printed map with QGIS, Print Layout is used. It can be used for adding multiple map views, labels, legends, etc.
As a free software application under GNU GPLv2, QGIS can be freely modified to perform different or more specialized tasks. Two examples are the QGIS Browser and QGIS Server applications, which use the same code for data access and rendering, but present different front-end interfaces.
Many public and private organizations have adopted QGIS, including:
“LTR” indicates a Long Term Release. Detailed changelogs are available for releases 2.0 and later.
Caption textVersionCodenameRelease DateNotes0.0.1-alpha2002-07First public release.1.0Kore2009-01-052.0Dufour2013-09-08New vector API, integration of SEXTANTE geoprocessing, symbology and labeling overhaul. Dropped “Quantum” from the name.3.0Girona2018-02-23Significant rewrite, upgrading to Qt5, PyQt5, and Python 3.3.2Bonn2018-06-223.4 LTRMadeira2018-10-263.6Noosa2019-02-223.8Zanzibar2019-06-213.10 LTRA Coruña2019-10-253.12Bucureşti2020-02-213.14Pi2020-06-19New temporal controller.3.16 LTRHannover2020-10-233.18Zurich2021-02-193.20Odense2021-06-183.22 LTRBiałowieża2021-10-223.24Tisler2022-02-183.26Buenos Aires2022-06-17Improved pointcloud and 3D support. New profile plotting framework.3.28Firenze2022-10-21
Quantum GIS is an open source GIS desktop software more popularly known as QGIS. QGIS 1.0 was first released in January of 2009 although development on the software began back in 2002 by Gary Sherman with the first versions of the software intended as a GIS data viewer for PostGIS. QGIS is increasingly becoming a viable alternative to commercial GIS desktop software options such as Esri’s ArcGIS suite of GIS software due to its user friendly interface and user support resources including an active presence within the GIS Stack Exchange section.
QGIS is a volunteer driven project that is licensed under the GNU General Public License. Built using C++, this open source GIS software can be downloaded for free, and runs on Linux, Unix, Mac OSX, and Windows operating systems. QGIS’ has a smaller file size and less RAM and processing requirements as compared to commercial GIS options. Similar to commercial GIS packages that use extensions, QGIS extends its capability through the use of plugins. QGIS also provides access to GRASS’ spatial processing modules through a GUI (graphic user interface). Custom plugins can be created using either C++ or Python. Supported data formats include Esri Shapefiles, PostgreSQL/PostGIS geodatabases, GRASS based vector and raster files, as well as GeoTIFFs. Two versions of QGIS are currently available: a stable build of QGIS 1.7.4 known as Wroclaw and a developer build version 1.9 that provides access to plugins and features still in development but is less stable and buggy.
The various components of QGIS per the start up tip:
- QGIS Library – this is the C++ library that contains the core logic that is used to build the QGIS user interface and other applications.
- QGIS Application – this is the desktop application that you know and love so much.
- QGIS Mapserver – this is a server-side application based on the QGIS Library that will serve up your .qgs projects using the WMS protocol.
Anita Graser describe the desktop, cloud, and mobile aspects of QGIS in her article, Introducing the Quantum GIS Ecosystem.
There are some great resources out there for learning how to use QGIS. The QGIS site has a “How do I do that in QGIS?” section that provides pointers on working with vector and raster databases, spatial analysis, working with different map projections, and making maps using QGIS.
Written for those seeking a broad overview on concepts relating to GIS, authors Tim Sutton, Otto Dassau and Marcelle Sutton have produced “A Gentle Introduction to GIS” (PDF format) using QGIS. The text is particularly aimed at educators as each chapters runs through that topic’s concepts, examples and then a “Now you try!” section. The PDF is divided into major conceptual areas of GIS: an introduction, vector data, attribute data, rasterd data, data capture, and more. You can find the individual worksheets, videos, and sample data that complement the text on the linfiniti.com. The document was sponsored by the Chief Directorate: Spatial Planning & Information, Department of Land Affairs, Eastern Cape, South Africa.
Anita Graser, the QGIS Community Assistant, has a personal blog called Free and Open Source GIS Ramblings that provides highlights and tips using QGIS. Recent posts include: mapping tree densities in Vienna, Austria using hexagonal grids, OSM styles for QGIS, and a guide to reliefs.
There are a host of video based tutorials for QGIS that have been posted to YouTube.
QGIS Labs is a set of ten lab assignments complete with sample data that can be self-led in order to learn QGIS. The labs were created by Richard E. Plant from UC Davis and use QGIS version 1.7.3.
Tips for Learning Open Source GIS
Diving into open source GIS isn’t as daunting as it once was with installer packages making it easy to get the software loaded onto your computer. User driven support groups also make it easy to get help. Here are some tips on getting starting with QGIS and some broader tips to incorporate when learning about any GIS software package:
First, start with the basics. Download the version of QGIS for your operating system and make sure it loads properly. Head over the the documentation section of QGIS and download the user guide. Section 2 of the guide has a sample session complete with a link to download sample data. Run through the steps to familiarize yourself with some of the basics of loading and symbolizing data in QGIS. Also review the tutorials found within the Gentle Introduction booklet mentioned above.
Don’t be afraid to experiment. The best way to learn is by trial and error. Come up with a mapping project idea that you can use QGIS for.
Take advantage of the peer support out there but don’t expect to have your hand held; peer users will help point you in the right direction but they aren’t there to take you step by step through your GIS issues. The QGIS forum is a great place to get help if you’re stuck after you’ve consulted the user guide and other online QGIS help documentation.