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Understanding an Ancient Roman City in Tunisia
By M. Carmen Locci, Archaeologist and GIS Manager, Cagliari University, Italy

Editor's note: In Tunisia, the ruins of the ancient Roman city of Uthina (in an area now known as Oudna) lie 31 miles (50 kilometers) from Carthage. Ten archaeological projects carried out in the central portion of the city between 1995 and 2002 have uncovered ruins including finds related to a hydraulic system that supplied water to the northwestern side of the city. This excavation is currently being carried out through a cooperative agreement between the Institut National du Patrimoine of Tunis and the University of Cagliari, Italy. A multidisciplinary team is using CAD for surveying structures and layers and storing the data gathered in a multimedia relational database that is accessed through a GIS-based map interface.

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This map illustrates that the shape area of blocks is homogeneous for Roman walls but irregular for more recent structures. The location of each mortar sample shown on the map is hyperlinked to a table containing the results of archaeometrical analysis.

The ancient Roman city of Uthina—with its ruins; an amphitheater; public baths; and great civic temple; the Capitolium—will be a wonderful destination for cultural tourists. The Archaeological Mission of Cagliari University (Italy) and Institut National du Patrimoine (I.N.P.) of Tunis are working together on a project excavating an urban area on the northeastern side of the hill from which Capitolium rises. Huge cisterns that stored the city's water supply from aqueducts are also located at this site.

Although it is well established that this splendid city of the Imperial Roman Age became a smaller Islamic town in the Middle Ages, little is known about either the types of buildings or the methods employed in their construction. An extensive and expensive archaeological excavation of the site was not feasible. However several scientific investigations are being carried out at the site including the excavation of a 425-square-meter trench that will be studied to better understand the city's hydrologic system.

Three departments at Cagliari University and the Italian National Research Council (CNR) have collaborated on this project. The Department of Architecture is supplying three-dimensional modeling. The Department of Chemical Engineering and Materials and the Institute of Environmental Engineering and Geoengineering at CNR will carry out chemical, mineralogical, and petrographical analysis of both finds and buildings. The Department of Archaeological Sciences will handle stratigraphic excavations and the classification of finds.

Data obtained from excavation describes the structures located, archaeological layers identified, and archaeological finds—in particular, pottery and fragments of marble decorations. Archaeometerists [scientists who analyze archaeological finds using modern instrumental techniques adapted from physics, chemistry, geology, and biology] not only wrote papers dealing with the analysis of glazed earthenware, coarse ware, and pottery technology but also produced surveys yielding CAD drawings and data sheets containing x,y coordinates. This information was stored in a relational database. The pictures and images were compiled into a digital archive.

Researchers used GIS to enable all the project's researchers to share information, generating a beneficial synergy. Map-based analyses performed in ArcGIS allowed for the immediate visualization of data so that hypotheses regarding a large structure of sandstone blocks and opus caementicium [i.e., a Roman construction technique that used cement mixed with fragments of brick and stone] could be created and tested.

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The distribution of Islamic pottery shows a localized concentration because shards of broken vessels, rubbish, and other debris were put in pits. The attribute information for pottery shards was made available from tables that were joined to shard locations.

In summer 2002, a GIS application was developed for the project. The application works on an Intel Pentium 4 computer with a 2 GHz processor and 256 MB of RAM running Microsoft Windows XP. It was created in ArcGIS 8.2 and uses the ArcGIS 3D Analyst extension. The stratigraphic unit (SU), the smallest unit recognizable during archaeological excavations, serves as the key for topographic data acquisitions and the relational database. Each SU has a numeric keycode that addresses the analytical data or classification.

The interpretation of the architectural structures has proved very interesting. The ability to map various combinations of raw building materials and mortars simplifies the process of distinguishing between more contemporary structures and the earlier, homogeneous Imperial Roman buildings and their hydrologic works. Examining the distribution of artifacts using GIS indicates that a lively, though smaller, community existed during the Middle Ages.

The interaction between GIS management and automatic drawing operations has led to more rigorous and formalized graphic conventions and has constituted the first step in understanding excavation results. As a result of a year devoted to normalization and organization of the data and its integration, all data maintained in tables is related to maps and the data flow for the project has been simplified. Although the archaeological dataset is now considered complete, it will be updated with the results of future research.

The application of the GIS to the urban settlement should improve the interpretation of the town planning and produce results superior to those obtained previously using conventional tools. The GIS will also be expanded with planning and environmental management applications aimed at developing cultural tourism.

For more information, contact

M. Carmen Locci, Archaeologist and GIS Manager
Department Scienze Archeologiche
Cagliari University, Italy
Antonio Corda, Mission Chief
Department Scienze Archeologiche
Cagliari University, Italy

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