GIS Software or “Geographic Information System” software is mapping software that links information as to where things are, with information about what the things are like.
As on the paper map, a digital map created by GIS will have dots, or points, that represent features on the map such as cities; lines that represent features such as roads; and small areas that represent features such as lakes. The difference is that this information comes from a database and is shown only if the user chooses to show it.
Each piece of information in the map sits on a layer, and the users turn on or off the layers according to their needs. One layer could be made up of all the roads in an area. Another could represent all the lakes in the same area. Yet another could represent all the cities.
When excavating a shipwreck using archaeological excavation methods, each item recovered is part of a layer within the shipwreck site. As artifacts are recovered, and their associated data is entered into the GIS, a series of layers are constructed that allow each item recovered to be associated with every other item.
GIS also provides a capability known as spatial analysis. This capability will allow relative distances between artifacts to be stored and interpolated as a means of interpreting archaeological information.
A GIS, properly implemented, coupled with sound excavation and documentation procedures, provides archaeologists with an especially powerful tool for effective study and management of archaeological excavations.
The images on the following page are samples of what can be done with GIS software. These images were provided by 3H Consulting Ltd., and were produced by their software package Site Recorder.