CHARACTERIZATION OF THE SUBSURFACE THROUGH JOINT HYDROGEOLOGICAL AND GEOPHYSICAL INVERSION

Characterization of the subsurface heterogeneity, monitoring groundwater dynamics, modelling flow and transport in the subsoil are of paramount importance for protection of groundwater quality, design of remediation plans, control of restoration activities. One of the key physical parameters that control groundwater flow and solute transport is hydraulic conductivity. Both hydraulic conductivity and electrical resistivity depend on porosity, water content and textural properties. Moreover, the difficulties of directly and effectively measure hydraulic conductivity makes the possibility of predicting it from geophysical measurements very attractive. Hydrogeophysics provides useful complementary techniques, both for hydrostratigraphic and hydrogeological characterization and for monitoring. It provides a minimally invasive approach to obtaining spatially-continuous data-sets, at a relatively high temporal and spatial sampling density. The general-purpose objective of this work is the development of a modelling tool for the subsurface characterization, in order to improve studies on groundwater flow and contaminant transport, with the specific goal of obtaining a spatial 3D parameter distribution of hydraulic conductivity and electrical resistivity. Such a tool profits from DC geoelectrical and hydraulic collected data, which are used in a joint geophysical and hydrological data inversion, with an approach similar to the Ensemble Kalman Filter.