Reconstruction and Simulation

The archaeologist strives to fully understand the type of society that once inhabited a particular site. As the environment plays a large role in any culture, archaeologists try to fully understand the surrounding environment of an archaeological site as it once was. Archaeologists try to figure out the type of surroundings that the ancient inhabitants faced every day. Landscapes tend to change over time. This is especially true where there is water. Coastlines can easily change over the years due to silting. Consequently, the modern landscape may not necessarily be the same one that the ancients faced. In order to understand the ancient life more, archaeologists try to reconstruct the ancient landscape. GIS can be used to reconstruct natural features such as shorelines and coastlines. (15) Archaeologists try to define site catchment zones in order to understand the type of resources and landscapes available to the society. (16) A site catchment zone is the total area used by a past society surrounding the site.

If details of landscape are known and entered in a database, GIS can use 3-D Analyst and Spatial Analyst (extensions of ArcView) to create simulations of what the environment would actually look like. Two applications of this are commonly used. They are line of sight and viewshed analysis. Using this technology, an archaeologist can actually "see" what the surrounding area must of looked like from the site. Line of sight analysis is self descriptive as it shows "what is visible on a surface, looking in a certain direction from a single point." (17) Viewshed analysis is more useful than line of sight when dealing with archaeology, as viewshed analysis can show all other archaeological sites that can be seen from the observation point. This analysis is important when looking at the relationships between sites in a common region. Simulation of the ancient landscape can help the archaeologist understand why a site was chosen were it was. The figure on the right demonstrates viewshed analysis of a site in Arizona. The larger box shows the map of the area while the inset box demonstrates what the landscape really looks like. Viewshed analysis helps to put archaeological sites in their original context. If there were a highly fortified site atop of a hill, one could use viewshed analysis to make the observation point from the top of the hill and see what defenders of the site would have faced with an attacking army.

From the website of the Institute for Cultural Landscape Studies of the Arnold Arboretum (http://www.icls.harvard.edu), © The President and Fellows of Harvard College.