In the last decade, GIS has dominated the discipline of Geography. It has also started to reshape the way history is taught. But what exactly is GIS? How does it work? How can it be applied to the the teaching of history? And what are some options for using GIS in classrooms?
What is GIS?
GIS is an acronym for Geographic Information System. This integrated collection of computer software data views and manages information about geographic places. This system can also analyze spatial relationships and model spatial processes. GIS provides a framework for gathering and organizing spatial data and related information so that it can be displayed and analyzed.
The previous definition might make sense to the technically inclined, but for the rest of us, a little explanation may be helpful. First and foremost, GIS is not cartography. In short, it’s more than simply making maps: GIS is like making interactive, analytical, super maps. GIS technology allows for the fast, real-time computation of spatial data to create and share maps. Geographers and students can then use this information to analyze and solve real world problems. Spatial data is any information that can be associated with a geographic location.
Take the image below, for example. The author of this map combined census data (income by county and population by county) to create a map that depicts per capita income by county throughout the United States. Using GIS, the author was able to calculate and visually represent two absolutely massive data sets and then combine them to create a third. Simply put, GIS is a method for organizing and analyzing information (populations and income) that has a geographic component (counties in the United States).
How does GIS work?
Geographic Information Systems require two basic components: a map and some geographical reference data. GIS displays data in “layered” forms. Each data set comprises its own layer in the program. Take a look at the image below for a better understanding of what is meant by layers. Any GIS project starts with a base map. The user can then add a series of layers consisting of topographical information, forest cover, the locations of infrastructure (such as roads and hydro lines), and any other geographical information. All of this data is layered to form the map which can then interact with other layers. For example, GIS could be used to find out areas most susceptible to salt damage from winter road run-off. If we assume the lowest lying, most densely forested area near a road, is most at-risk for salt damage, these criteria can be entered into a GIS program to isolate ecologically sensitive areas. This information could then be used to established prevention and remediation programs.
GIS in the Classroom
HGIS: Historical Geographic Information Systems
HGIS takes all the principles of GIS and applies them to the discipline of history to analyze change over time. This can be done in many ways. One of the most popular applications of GIS to history is to geo-reference historical maps. When historical maps are placed and aligned over a contemporary one, or when a series of historical maps can be aligned, things like land use change over time can be represented visually. HGIS is also extremely useful for analyzing historical data such as a census. The first image we discussed depicting per capita wealth by county could be expanded by adding the same data from different years to analyze how wealth distribution has changed over time in the United States.
Quantum Geographic Information Systems, or QGIS, is open-source GIS software that is completely free to download and operate. Being open-source and relying on volunteerism and donations means that QGIS does not offer the same level of support that larger, pay-for-use programs have. A number of free online tutorials for QGIS are available, but their quality varies, and finding a tutorial that uses the same version of QGIS that you are using can be challenging.
While Google Earth does not have the same analytic capabilities of QGIS, it has the benefit of being a familiar and user-friendly platform. It is only a small leap from using Google Maps to looking up the fastest route for your road trip to using Google Earth to performing GIS functions. Google Earth also has a high degree of support built into the program and available online in user forums and tutorials. Google Earth is also a much smaller program than QGIS is, so the former can be run from virtually any computer or laptop. The bulkiness of the GIS programs can also cause them to function slowly when users operate on computers with less power.
Learning any new program can be intimidating. Thankfully, there are many online resources available that outline both the basic and advanced functions of the programs discussed above. Below you will find a list of articles, online tutorials, and teaching resources to help you get started using GIS:
- Geospatial Historian: Open HGIS Lessons and Resources
- Teach GIS: “because no one should have to face GIS alone”
- GIS for History: Bringing Historical Census Data Alive!
- GIS for History: Projects
- ESRI: How does GIS Work?
- Interactive Great Migration Maps
 ESRI, “GIS Dictionary,” accessed March 3, 2015, http://support.esri.com/en/knowledgebase/GISDictionary/search.
 Pennsylvania State, Department of Geography, “4.2 Attribute Measurement Scales,” accessed March 3, 2015, https://www.e-education.psu.edu/geog160/c3_p8.html.
 A. Th. Ibraheem et al, “Coupling GIS and Photogrammetry for the Development of Large-Scale Land Information System (LIS),” Journal of Geosciences and Geomatics 2, no. 1 (2014): 1-10. Found on “Science and Education Publishing”, accessed March 3, 2015, http://pubs.sciepub.com/jgg/2/1/1/.
 David Rumsey Map Collection, “MIT Technology Review on David Rumsey’s Work,” accessed March 4, 2015, http://www.davidrumsey.com/blog/2005/7/1/mit-technology-review-article.