A GIS approach to the study of megalithic tombs

We know over 200 Sardinian dolmens of various types. The rise of the phenomenon seems possible to ascribe during the culture of San Michele of Ozieri (Late Neolithic, 4000 – 3300 BC). However, the Sardinian dolmens had the widest possible dissemination during the Chalcolithic. The Sardinian phenomenon shows a close relationship with dolmens of Catalonia, Pyrenees, non-coastal departments of French-midi, Corse and Puglia. In the study of megalithic tombs, the analysis of the relationship with the surrounding territory can be an important aid. In this work, we place dolmens and landscape in connection. To understand this relationship, we used the tools offered by GIS. This approach – based on geo-referenced data and a three-dimensional representation of landscape features – can assist the archaeologist in interpreting the ancient landscape. Among the potential of GIS, the possibility to evaluate – with the creation of a model of the costs of travel – the main trends relating to the movement in relation to the geomorphological characteristics of the territory is particularly interesting. To test the possibilities offered by this type of analysis, a sample area in north-east of the island of Sardinia (Italy) was chosen. The results of cost distance and visibility analyses showed locations in areas that would enhance the function of spatial markers linked to transit or contact areas, for most of the analysed samples. These were probably in connection with pathways functional to internal trade between islander groups. Furthermore, these are probably related to short or long processes of transhumance.