QGIS is open source, and similar to proprietary GIS software, runs on a variety of operating systems, and has been steadily improving since its debut in 2002. With easy-to-install packages, OpenGeo Suite integration, and reliable support offerings, QGIS is a viable alternative to proprietary desktop GIS software. Here, Gretchen Peterson of Boundless explores how QGIS works for visualization, cartography, GIS analysis, and editing data – Peterson analyzes how QGIS stacks up in vizualization, cartography, GIS analysis and editing data
Any GIS professional who’s been paying attention to the professional chatter in recent years will be wondering about QGIS and whether or not it might meet some or all of their needs. QGIS is open source, similar to proprietary GIS software, runs on a variety of operating systems, and has been steadily improving since its debut in 2002. With easy-to-install packages, OpenGeo Suite integration, and reliable support offerings, QGIS is a viable alternative to proprietary desktop GIS software. Here, we’ll explore how QGIS works for visualization, cartography, GIS analysis, and editing data.
QGIS Compared: Visualization
QGIS works for visualization of most formats of spatial data, for analysis of raster and vector data, for geographic data editing, and for cartography. A key strength of QGIS is that it is versatile and has efficient format support. QGIS is an effective means of viewing and exploring spatial data of almost any type. If you have complex data, you might be interested to hear that the newest release of QGIS boasts very fast, multi-threaded, rendering of spatial data that may even make it faster than leading competitors. In the realm of visualization, it does most of the other tasks that a GIS professional would expect as well, including support for custom symbol sets (in SVG format).
The other important aspect of visualizing data is having enough underlying context for the data. Country boundaries, city labels, roads, oceans, and other standard map data are crucial. Proprietary GIS software generally contains basemap layers that can easily be turned on and off to support visualization in this manner. QGIS also has this capability, in the form of the OpenLayers plugin, which serves up Google, OpenStreetMap, Bing, and Yahoo basemaps at the click of a button.
While QGIS may need a small amount of improvement when it comes to raster visualization and on-the-fly projection, these aren’t hindrances to a typical visualization workflow, but it immensely useful when editing and navigating a wide variety of spatial data.
QGIS Compared: Cartography
When it comes to cartography, QGIS is easy and straightforward to create maps. Among its strengths include text and image elements, advanced techniques and color blending. Placing text and images is an easy two-click process in QGIS and advanced capabilities include an leading labeling functionality. Another advanced technique is the creation of atlases and provides an atlas composer as part of the core functionality within the Print Composer, a very powerful feature. Additionally, QGIS now has color blending modes, typically found only in design software, that can add special effects to the look. One hidden gem of QGIS is the gradient fills, also known as vignette effects, are also possible, in a new plugin called Shapeburst.
A few mixed results come from QGIS for cartography in its map elements and sizing
the cartographic capabilities of QGIS are sufficient to produce almost all the common map layout components with an adequate amount of advanced capabilities and even some options, like the color blending modes, that aren’t typically found elsewhere. Overall, QGIS’s visualization, cartography, and editing functions have matured to the point where GIS professionals of all types can’t afford not to strongly consider adopting it.
QGIS Compared: GIS Analysis
QGIS is easy-to-install, integrates with OpenGeo Suite, and has reliable support offerings, making it a viable alternative to proprietary desktop GIS. Many of the analytical capabilities in QGIS will pleasantly surprise the seasoned GIS analyst. The tools are easy to find and are intuitive to use. For example, inputs self-populate with any data already loaded into the project and many of the processes run faster than on heavier-weight proprietary GIS software.
QGIS has made some improvements to the typical GIS workflow. Not only can column (field) names be changed, but there is now an easier way to calculate new field values than the field calculator. Attribute calculation and manipulation is therefore directly comparable to that found in proprietary GIS, and with the new expression box, perhaps even easier.
Additionally, working with vectors is considered an edit task in other software and is therefore included in the pricier editing versions of the software. There are two types of generalizing to consider: smoothing and simplifying. Smoothing decreases small curves (e.g., a river that generally follows a single arc but has many sinuous curves along the way could be smoothed such that the smaller curves are eliminated for small scale visualization).
For common analytical workflows, QGIS works quite well. For a free software product it may even be surprising that it includes many analytical procedures that are usually thought of as advanced and priced accordingly. The analytical capabilities in QGIS are such that, as with visualization, cartography and editing, it can absolutely be considered a viable alternative to your current GIS software.
QGIS Compared: Editing Data
While editing spatial data is not something that everyone does, it is definitely an important component of desktop GIS. QGIS strengths in editing include creating shapefiles, copying & pasting, snapping and topological editing, and working with vectors.
A hidden gem lies in some of the advanced feature construction tools that developers might be familiar with such as points at invisible intersections, regular arcs, Bézier curves, and trace aren’t available in the core QGIS software but they are available in plugins. One of the most notable plugins for advanced feature construction is CadTools. CadTools provides 13 advanced tools for workflows that require high accuracy at large scales.
Though QGIS editing tools may appear basic, they serve extensive purposes with add-ons. If the basic tools aren’t enough, the plugins come to the rescue with advanced functionality. As with visualization, cartography and analysis, it’s clear that the QGIS developers are cognizant of the demands that we GIS professionals put on our software in terms of needing exacting, fool-proof, and robust editing tools and they have made great progress in meeting those needs.
With readily available packages, OpenGeo Suite integration, and dependable product support, QGIS is a practical alternative to proprietary desktop GIS software. Through navigating how QGIS works for visualization, cartography, GIS analysis, and editing data it’s easy to see that the robust visualization capabilities that QGIS offers provide more than enough impetus for many organizations to make the switch to QGIS
By: Gretchen Peterson (@petersonGIS), Data Scientist at Boundless
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