A GIS-based Study of Attica
|January 3, 2012||Posted by Sylvian Fachard under Art/Archaeology, Blog, History|
A GIS (Geographical Information System) is currently being built up for the landscape study of Attica’s borderland. GIS offers a convenient and powerful tool for adding geographical, geological and historical maps, processing archaeological data and analyzing the geomorphology and the land-use of a historical landscape. GIS is a unique tool for integrating a variety of complex data, including Attica’s immense archaeological heritage. By bringing together different sources of information, the technology can help us rebuild the historical landscape of Athens’ chora by analyzing, for example, the distribution of archaeological sites of a given period on a digital elevation model (DEM), and then linking them with the different types of soils and modern land-use categories (non-irrigated arable land, forest/maquis, pasture, etc.). Such an analysis helps us understand settlement choices, the agricultural potential of the different microregions that compose Attica and the evolution of settlement patterns through time. I believe it is a powerful tool for mapping and studying Attica’s borders. To my knowledge, this is the first GIS-based study of northern and western Attica.
I’m currently working on the database integrating the archaeological data. Based on the information provided by published material (monographs, excavation reports and site by site reports from various sources), each archaeological site known between Athens, Thebes and Megarais inserted into the database. Basic information is provided for each site, including name, geographical coordinates, chronology, nature of the site (grave, settlement, isolated wall, surface pottery, etc.), bibliography and context of discovery (chance find, rescue excavation, surface survey, etc.). The display of the site-database as a “table” in the GIS software allows a quick visualization of the distribution of archaeological sites in northernAttica. By selecting all the sites known for a given period, it becomes convenient to draw maps showing the different sites known for each period and, for example, showing the drop of known sites north and south of the Parnes mountain range between the Late Helladic IIIB and IIIC.
DEM of northern and western Attica displayed on QuantumGIS (MG/SF2011).
Adding layers of information
More information can be added to the GIS by creating different layers. For example, I started adding older maps, such as Curtius and Kaupert’s Karten von Attika, in order to digitize the precious (and often lost) information they contain, from old Turkish khans to ancient remains. I’m progressively adding thematic and human-related information layers such as the ancient road-system, the springs, the most productive agricultural soils, the Attic demes, the main settlements, the sanctuaries and the Boeotian poleis. The combination and the visual display of these different sources of information offer powerful tools for studying the rural settlement patterns. But can they help us to localize the border zones between the Megarid, Boeotia and Attica?
GIS is more than a mapping tool. It allows conducting different analyses, such as a “nearest neighbor analysis”, Thiessen polygons, “walking-distance” and “shortest path” analyses. These are helpful for recreating ancient roads, mapping economic surfaces used by communities and settlements, or for measuring the sizes of ancient deme territories. In the case of border studies, I believe that different analyses can help us to localize them on the ground. For example, basing myself on the assumption that an important portion of Attica’s borders was situated in mountainous regions and that most of the border landscape was lightly inhabited in comparison with the plains, GIS can be used for highlighting the zones with the steepest slopes and the lowest site-density per period. The resulting map should be used as hypothesis as well as a guide for further reconnaissance and survey on the ground. This is an obvious application, but new analyses will be developed as new questions and hypotheses emerge.
GIS-based studies are interdisciplinary. In order to bring together layers of information derived from different disciplines such as geology and geomorphology, an archaeological GIS requires the participation of specialists working in other fields. The present GIS is being built with my colleague Dr Matthieu Ghilardi, chargé de recherches at the French CNRS (UMR 6635 CEREGE). Dr. Ghilardi is responsible for providing the different landscape datasets. Our collaboration includes future developments, such as the drilling of cores in some marshy lowlands in order to recreate the evolution of the landscape of selected microregions and to study the erosion history of some Attic plains situated in the borderland. As an active platform for collaboration, our GIS should include the collaboration of different specialists in the future.
 Such a study has been achieved for Boeotia, see E. Farinetti, Boeotian Landscapes. A GIS-based study for the reconstruction and interpretation of the archaeological datasets of ancient Boeotia; Bar International Series 2195 (2011).