QGIS

QGIS, previously known as Quantum GIS, is one of the two desktop applications produced by the not-for-profit Open Source Geospatial Foundation. QGIS is free and available across platforms (Windows, Macintosh, Unix, and an upcoming release on Android), and its source code is extensively documented. It is a simpler and more user-friendly program than GRASS GIS, its more heavy-duty OSGeo sibling; where GRASS GIS is intended for intense scientific data processing and targets a user base of GIS analysts who are familiar with programming, QGIS features a relatively intuitive graphical user interface, and it is much easier to learn, while at the same time being fully interoperable with GRASS GIS and other GIS programs.

 QGIS is intended to serve as a free, interoperable, and non-proprietary alternative to ESRI’s ArcGIS. The base QGIS application comes with a fairly extensive library of geospatial data processing capabilities, and its visual customizability is virtually limitless. Furthermore, a wide array of plugins are available to add to the base program; some of these plugins are designed for scientific applications, but others are of particular interest to digital humanists. The most notable of these is TimeManager,  which allows for temporal data manipulation and the creation of time-lapse animations.

 While QGIS’s base program functionality is narrower than ArcGIS’s, the plugin library extends the program’s functionality such that nearly anything possible in ArcGIS is possible in QGIS—and QGIS even has some functionality that ArcGIS lacks. However, QGIS (while possessed of a markedly less steep learning curve than GRASS GIS) is not a good fit for novices, and even users experienced with GIS may find it difficult to learn.

Example Applications

QGIS was an underlying technology for one of the most prominent digital humanities GIS projects, ORBIS: The Stanford Geospatial Network Model of the Roman World. This project uses QGIS to its maximum potential, and demonstrates the tool’s functionality and some of its advantages over the ArcGIS desktop application. Due to QGIS’s open-source data formatting, the ORBIS team was able to create a highly interactive web-based map which features extensive data manipulation capabilities. They were able to host this project on their own servers, rather than on a proprietary and minimally-customizable web platform.

One of ORBIS’s authors, Elijah Meeks, highlighted one of QGIS’s unique functionalities in a blog post in October 2011.¹ In it, he notes that QGIS allows simple copy-pasting into Drupal Geofields, with no reformatting required. This feature appears to only be available in QGIS, and may save time and effort for digital humanists who are working with Drupal.

Digital Humanities Potential

QGIS’s base program facilitates the creation of static, thematic, visually-customized maps—but by installing plugins and/or porting map data into a web-based format, QGIS can also accommodate time-lapse animations and web-based interactive data manipulation. While no timeline manipulation function is native to the tool or any of its existing plugins, such a tool could certainly be developed by a sufficiently technically-adept scholar. Of the GIS desktop applications, it is best suited to accommodate the creation of interactive interfaces hosted on a home institution’s server, though the web platform for such an interface would have to be manually constructed.

QGIS’s quantitative data processing capabilities, default anonymized authorship, and modest ability to accommodate interactivity and ambiguity make it a poor fit for digital humanities projects requiring ambiguity or conceptual abstraction. It is a strong fit for projects with a heavy quantitative or sociological component (demographic histories, documentation of the movements of languages or ethnic groups) or for projects integrating static spatial-temporal point values (military histories, archaeological datasets).

This tool is generally better suited to aggregated data than individual-level histories, and it is not inherently welcoming to geospatial links with images or other multimedia; nor is it particularly hospitable to explanatory texts. It would be an awkward fit with geospatial histories of individuals or social networks, and is patently unsuited to projects requiring plural attribution or visibly-authored commentary; therefore, QGIS is a very poor fit for archival projects.

Advantages

With judicious deployment of plugins, QGIS offers very similar functionality to ArcGIS—but at no cost, across operating platforms, and without relying on proprietary file formatting. QGIS data is highly portable, allowing collaboration between users of different GIS tools. Data processing capabilities are sophisticated, and visual customization is extremely flexible. QGIS’s learning curve can be mitigated by the tool’s extensive documentation, and in some ways it is more user-friendly than ArcGIS—for instance, in the menu placement and explanatory graphics for the geoprocessing tools.

For digital humanities projects requiring heavy quantitative processing, but without institutional or monetary access to an ArcGIS license, QGIS may prove an ideal solution.

Drawbacks

Like many open-source projects, QGIS assumes that its users possess a certain level of programming comfort, and it may be somewhat daunting for those accustomed to GIS programs in which the workings are more concealed. It is significantly less programming-heavy than GRASS GIS, but it still assumes that users will understand the technical terminology used in its menus and command windows. And, while QGIS’s cross-platform compatibility is a significant selling point, the program download process is significantly more complex for Mac users than for those using PC; Mac users must download and install the underlying Python frameworks manually and in a specific order, while QGIS and its framework are packaged together for PC users.

QGIS can also be a little buggy. The author’s experiments with the Macintosh version of QGIS sometimes resulted in data input peculiarities; for example, latitude-longitude coordinates in a .csv file did not translate into the correct point values, while other tools tested were able to process the same dataset with ease. (It bears noting that ArcGIS sometimes displays similar bugs.) Reporting QGIS bugs is strongly encouraged by its developers, and patches are released frequently, but users must be on the lookout for errors.

External Links

• QGIS
• QGIS user guide
• QGIS wiki
• TimeManager plugin