Fieldwork: GIS and Archaeology

By Bryan Haley, Time Team Geophysicist

Time Team America archaeologists collect a huge amount of diverse information for each shoot. The locations of surface features, geophysical readings, excavation trenches, artifacts and anything else of interest encountered during excavation are meticulously recorded. This information is pulled together by archaeologists to help learn about the site and one of the most important tools for accomplishing this is GIS.

GIS is an acronym for "geographic information system", which is a computer-derived collection of different kinds of spatial data. Basically, it is a map mixed with a database so that any information that is added to it is linked to a coordinate. Most importantly, the data can easily be queried, analyzed, and displayed automatically.

How exactly does GIS help archaeologists? Archaeologists try to reconstruct past behavior and understand how this behavior changes over both time and space. The only clues are the items left behind from the activities of the past and how these are patterned. GIS software includes techniques that allow the patterns in large volumes of information to be easily analyzed and, in some cases, allows relationships to be recognized that might otherwise not be. Once these relationships are discovered, GIS can be used to create a map so that the data is easier to understand.

When you only have three days on a site, like Time Team America, GIS is even more of a necessity. For example, if an anomaly is located in the geophysical data, GIS can be used to determine exactly where the excavation should be placed to investigate it. Accomplishing this by hand would greatly cut into our time on site.

Even before they arrive on site, GIS can be used to give the archaeologists a head start. Coordinates can be added to existing types of data, such as historic diagrams, excavation plans, and aerial photographs. These can also provide valuable information in planning excavations and in understanding what is encountered during excavations.

GIS can also be used on a regional scale to better understand how sites are distributed across the landscape. Most states now maintain a GIS of sites in order to manage their archaeological resources. In some cases, GIS can even be used to predict the location of unknown sites.

Over the last ten years, advances in the speed and storage capacity of computers have enabled GIS to be used to present the data in new and exciting ways. Archaeological sites can now be rendered in three dimensions to allow the viewer an experience that is closer to the real world.