The impact of geo-hydrological hazards on cultural heritages represents a multi-disciplinary theme, which requires several different approaches.

A joint project among three different departments of the University of Florence, lead to a new investigation campaign on this tumulus. Four radial 2D- electrical resistivity tomography (ERT) were carried out. The main aims were to verify the structures conservation state and to identify the ancient tomb access. The results of the preliminary analysis of the influence of GPS error on the apparent resistivity data suggest that, in case of consistent GPS uncertainty, caused by physical and atmospheric conditions, the shallow apparent resistivity is strongly influenced by a wrong deployment of electrodes. Therefore, in case of archaeological application, where the investigation depth is limited to the first meters below the ground surface, the measurement campaign should be rescheduled in a different period, when different conditions will occur. This leads to an improvement of ERT data quality and, consequently, to a better accuracy in the localization of the archaeological target, with a minimization of the excavation cost.