Non - invasive methods for the identification of multistratified medieval urban structures: integration between GPR and ERT surveys

Project leaders

Salvatore Piro, Andrzej Buko

Agreement

POLONIA - PAS (NUOVO ACCORDO) - Polish Academy of Sciences/Polska Akademia Nauk

Call

CNR-PAN 2017-2019

Department

Social sciences and humanities, cultural heritage

Thematic area

Social sciences and humanities, cultural heritage

Status of the project

New

Research proposal

Referring to the knowledge and safeguard of the archaeological sites and their historical buildings, in particular when these sites are located inside an urban area as the case of medieval structures, the questions about the application of the non-invasive surveying methods are the following:

a) the definition of the high-resolution acquisition techniques for the Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) methods in the urban contest;
b) the development of the specific high-resolution processing techniques;
c) the definition of the quantitative integration technique for different geophysical methods;
d) the development of the 2-D and 3-D representation and visualisation techniques.

The Ground Remote Sensing Lab (GRS_Lab) of ITABC, on the base of its experiences made during the last twenty years, will develop the integrated geophysical prospecting method, with the aim to reconstruct the location, the extension, the shape, the depth and the spatial correlation of the archaeological structures in two selected archaeological sites. The main aim of the present project is the development of the integrated geophysical approach to investigate the medieval archaeological sites in urban and suburban area in Poland and Italy, comparing the enhancement of the knowledge about two selected sites.
For the field application, two particular sites, Sandomierz (Poland) and Semifonte (Italy) have been selected. These sites are characterised by different hypothesised archaeological structures and different soil conditions.
Sandomierz is a medieval town, characterised by loess soil in the ground and the polish team suggest to investigate the following churches:
o San Giacomo Church (XIII s.), survey to locate the crypt below the actual church, to verify the presence of remains of the pre-dominican church and to reconstruct the ancient topography of the religious building.
o San Giovanni Church (XI s.), survey to identify the remains of the hypothesised building.
o Vergine Maria cathedral (XII s), survey to reconstruct the ancient topography of the hill.
o Sant' Adalberto Church (XI s), survey to locate the remains of the church.
Semifonte was a medieval town in Valdelsa (Tuscany region, Italy), completely destroyed by Florence in 1202 and represents, from the historical point of view, an interesting case study. Nowadays only the toponym of the site still remains, without any structures of the medieval buildings. The location of the structures of Semifonte represents an important aspect for the identity of the people leaving in this site.
In particular Semifonte site represnts an extraordinary example of the foundation of Conti Alberti's town, successively destroyed by Florence. The site is characterise by high potential archaeological stratigraphy that can be investigated firstly employing non-direct survey methods, as geophysical prospections, jointly with high resolution topographical 3D surveys and remote sensing acquisition with drone. In this case the main objective of the study is to identify and reconstructe the archaeological thickness (overlapping of remains of structures), also in the case where the buildings have been destroyed. Semifonte site will be studied and surveyed in collaboration with Prof. Guido Vannini (Medieval Archaeology) of Florence University (Italy) and his team. The geophysical surveys will be made through the agreement with the local Soprintendenza Archeologica della Toscana (public istitution of the Cultural Heritage Ministery).

In the project multi-methodological surveys will be carried out for detecting superficial urban remains employing: the Ground Penetrating Radar (GPR) and the Electrical Resistivity Tomography (ERT) methods with an integrated approach. For the topographical survey the employment of the Total station and D-GPS (differential Global Position System) with high-accuracy and kinematics acquisition technology, together with remote sensing acquisition by drone, allows us a high-resolution analysis of the investigated environment.

L'ITABC will support the project with the GPR system, equipped with different antenna (different frequencies), the multielectrode resistivity system for the geophysical surveys and the total station and D-GPS for the topographical surveys.

The benefit to both sides from this collaboration are the following:
o the enhancement of the scientific collaboration, between two teams, about the employment of non-invasive techniques;
o the exchange of experiences about the employment of GPR method equipped with different antenna and ERT in the case of medieval archaeological site;
o the aim to publish the results of this project with ISI international journals;
o the possibility to show the obtained results in the international conference;
o the feedback of the results with the direct archaeological investigations.

The two groups agree to publish the results of the project in national and ISI international journals and proceedings of conferences.
This project represents the new continuation of previous collaboration between CNR (ITABC) and IAE (dating from 1970) based on the first employment of the geophysical techniques (resistivity method) to investigate archaeological sites. In that period, through this collaboration, new acquisition techniques and new instruments have been developed, obtaining positive results helping polish team to employ and develope these kind of researchs.

Research goals

Definition of the high-resolution acquisition and elaboration techniques to express the integration of the selected methods. Geophysical surveys for all selected areas.
Definition of the high-resolution acquisition and elaboration techniques to identify as structures or discontinuities inside the historical buildings as the variations on the fabric of the ancient walls and cavities.
Extensive geophysical surveys for all selected areas.
Comparison between the obtained integrated results and the direct archaeological excavations.
Diffusion of the results through papers in ISI scientific journals, presentation in international conferences and dissemination through dedicated web-sites.

Last update: 27/04/2024