Geographical Information Systems (GIS) is a necessary tool for all researchers in the field of archaeology regardless of area of expertise. Archaeology above all things is a science of material culture and a critical facet of understanding material culture is interpreting the relationship between material culture across the landscape and also how material culture is related to different components of the landscape. Archaeology is like a great detective story, it is an attempt to understand pieces of an unknown puzzle.
A key principle in the geographical sciences is that the closer things are to each other the more related they will be.
Archaeologists use this principle to understand past human behavior by mapping in the location of sites, their features and artifacts. By examining the spatial distribution of artifacts and sites – archaeologists can then interpret past spatial behaviors at a site, and the different types of activities that took place across a region and within their territories.
There are 4 key benefits of using GIS in archaeology:
1). Examining spatial patterns across a site or region for interpreting past behavior. Included within GIS packages are powerful spatial statistics.
2). Correlating the relationship between sites, or individual artifacts within sites to the landscape. The landscape in GIS can be modeled with such things as elevation, distribution of water, location of lithic resources, most prominent landmarks, etc.
3). Making pretty maps. A lot of archaeologists stop at this level of expertise, and this is an important aspect. Archaeology is a visual science and making great maps are important for displaying the location of artifacts and sites on the landscape.
4). Managing data. The story of archaeology is told across space and time. GIS offers a great database function to manage information that is tied to a place on earth. Artifacts collected in the field occur from a particular place with an x,y,z coordinate, however, intangible information can also be tied to space, such as an oral history told by an elder about a particular site or place.
ArcGIS: is the most popular commercial software coded by ESRI out of Redlands, California. It is very expensive, but most universities do have an academic license for this software. The main benefit of ArcGIS is that it is easy to use, and this is the main type of software taught at universities.
Grass GIS and QGIS: Grass GIS was developed by the U.S. Army with the help of several universities and other federal agencies. This software is free! It has been around a long time and is now a lot more user friendly to start up and use. There is more of a learning curve in getting started, but for coders I feels this software offers many more benefits to developing add-on specific applications than for ArcGIS.
Caveat: I am not a coder, but have learned to work through the specific commands of the software.
I have been using Grass GIS for several years now and prefer it over ArcGIS for some functions, but I use both in combination. I was attracted to Grass GIS early on due it’s availability on Macs – ArcGIS only works on PCs. Another big difference between ArcGIS and Grass GIS is how it handles files. In ArcGIS different types of files can be scattered all across the hard drive of a computer. I have spent countless hours for an important source of data that I have put in a subfolder and can not relocate. If you are working on a map with a data source and move that file in an organization attempt to clean up your hard drive, then ArcGIS will not be able to display the information on the map. Although in recent versions of ArcGIS, ArcGIS will automatically load other data sources within the same map if you can locate one of the files and if the data sets are within the same folder. In contrast, Grass GIS stores your datasets within its specific folder structure system associated with a particular map and projection. Therefore, you are less likely to lose data on the computer, but it is a more rigid system and requires that all of the data is in the correct projection and set geographic boundary. I spent a lot of time figuring this out about Grass GIS.
QGIS (Quantum GIS) is a more user friendly shell for GIS and works with Grass. It is also open sourced it works on most platforms including a mobile Android version. If you are interested in Grass GIS then you will also use QGIS.