Articles by Salvatore Piro

The site of Norba is located in the Latium Region, about 90 km S of Rome, Italy. The city is one of the best example of urban town planning, with a regular layout dating back to antiquity. Over the years, many studies and archaeological excavations have brought to light important remains of several buildings, which are still very well preserved. To enhance the knowledge of the unexcavated portions of the archaeological site and to locate the position of the unknown and hypothesized buried structures, extensive geophysical surveys employing the Ground Penetrating Radar (GPR) and Gradiometric methods were planned and conducted between 2017 and 2018. For the measurements, a GPR system SIR3000 (GSSI), equipped with a 400 MHz bistatic antenna with constant offset, was used to survey 27 different sectors close to few excavated areas. Taking into account the environmental conditions of the site and the nature of the buried structures, some areas were surveyed with a spacing interval between parallel profiles of 0.25 m while other areas were investigated with a spatial interval between closed parallel profiles of 0.50 m. Furthermore, fluxgate differential magnetic (Gradiometric) surveys were carried out using the geoscan FM256 in two areas, overlapping the GPR areas. In order to have a better understanding of the subsurface, methods of qualitative and quantitative integration of the results have been employed: maps overlays and RGB color composites (graphical integration), binary data analysis and cluster analysis (discrete data integration), and data sum, data product and principal component analysis (continuous data integration). The results obtained from the geophysical surveys were interpreted together with the archaeologists to define the meaning of the structures identified and to enhance the knowledge of the ancient town’s layout and mapping.

In general, a territory can be considered as the centre which contains all information related to different historical ages. The study of a portion of a given territory characterised by the presence of archaeological sites must be aimed at the complete and accurate acquisition of environmental data (e.g. topography, geo-morphology, litho-stratigraphy, land use, etc.), which will be used for an overall study of the site, the reconstruction of the man-environment interaction, and the evaluation of possible applications of geophysical prospecting methods. By interpreting different sets of remote-sensing data, studying existing geological and geo-morphological information and through systematic field work (e.g. archaeological survey, geophysical investigations, etc.), a wide spectrum of environmental data can be collected. The methodology of a complete analysis of the territory can be summarised as follows: analysis of remote-sensing data sets and their geo-referencing; DTM of the selected study area; morphological and geological definition of the selected study area; identification, location and geo-referencing of all archaeological sites in the territory; high-resolution integrated geophysical prospecting methods, to delineate the extension of the site and to locate the archaeological structures; a complete description of the site in its environmental context; definition of an integrated analysis method, based on the spatial correlation of the different data sets; study and design of a GIS for the management of all data sets which have been collected, elaborated and interpreted; definition of a model for the knowledge and protection of the historical and environmental aspects of the territory.