Geophysical Imaging Used to Appraise Subsidence Modelling - The Case of Valtonera (Amyntaion, NW Greece)

In this work we demonstrate the combined use of ERT and seismic methods as a tool to assess geotechnical models used to evaluate subsidence due to ground water level drop at the area of Valtonera in (NW Greece). The simulations were applied on certain geotechnical models corresponding to the studied geophysical lines which were measured over existing fissures. The geotechnical model parameters were based on the corresponding seismic data as well as on previous geotechnical studies carried out in the same region. Furthermore, the detailed structural information which was retrieved by the ERT sections was introduced directly into the geotechnical model and provided a more realistic basis for calculations as opposed to the oversimplified lithological models that are typically used when structural geological information is missing. Such geotechnical modelling resulted from the integration of the geophysical information of the investigated area, correlates well with the subsidence observed in the field. Hence, the proposed approach can be used to provide more realistic localized displacement measures at specific localities.