Geophysical Constraints to Reconstructing the Geometry of a Shallow Groundwater Body in Caronia (Sicily)

Abstract

The characterization of a groundwater body involves the construction of a conceptual model that constitutes the base knowledge for monitoring programs, hydrogeological risk assessment, and correct management of water resources. In particular, a detailed geological and geophysical approach was applied to define the alluvial Caronia Groundwater Body (CGWB) and to reconstruct a hydrogeological flow model. The analysis of the CGWB, located in north-eastern Sicily, was initially approached through a reanalysis of previous stratigraphic (boreholes) and geophysical (vertical electrical soundings and seismic refraction profiles) data, subsequently integrated by new seismic acquisitions, such as Multichannel Analysis of Surface Waves (MASW) and horizontal-to-vertical seismic ratio (HVSR). The analysis and reinterpretation of geoelectrical data allowed the construction of a preliminary 3D resistivity model. This initial modeling was subsequently integrated by a geophysical data campaign in order to define the depth of the bottom of the shallow CGWB and the thickness of alluvial deposits. Finally, a preliminary mathematical model flow was generated in order to reconstruct the dynamics of underground water. The results show that integration of multidisciplinary data represent an indispensable tool for the characterization of complex physical systems.

Coastal Groundwater Bodies Modelling Using Geophysical Surveys: The Reconstruction of the Geometry of Alluvial Plains in the North-Eastern Sicily (Italy)

“…The shallower layers, characterized by an average value of 350 m/s and thickness varying from 5 to 30 m, should represent the alluvial and coastal deposits that predominantly outcrop along the plain. Several previous studies [19,81,82] attributed these velocities to sediments from coarse-to fine-size that usually fill the alluvial plains. The layers, with an average value of 600 m/s, correspond to the intermediate portions of the Vs-profiles.…”

“…The lithology and stratigraphic setting of the sedimentary infill directly influence the groundwater circulation and its storage in the SCGWB and BMGWB. The Potential Infiltration Coefficient (CIP [19,58,59]) can be considered as the parameter through which the permeability of rocks and sedimentary deposits is quantified. As regards the Groundwater Bodies characterising the Sant'Agata-Capo d'Orlando and Barcellona-Milazzo coastal plains and related rivers and all tributaries, the CIP reaches the highest values (0.8-0.9%) estimated in the PC [33].…”

“…In these studies, acquired geophysical data constrained by the information derived from direct investigation provide a fundamental tool for the integration and definition of subsurface models. Even hydrogeology research exploits this workflow for numerous purposes: the description of groundwater depth and thickness [17][18][19], definition of the physical-chemical characteristics of an aquifer [20][21][22], assessment of marine ingression in coastal areas [23][24][25] and evaluation of water quality and degree of pollution [26][27][28].…”

Enhanced Groundwater Protection and Management Using Gravity and Geoelectrical Data (Valls Basin, Spain)

“…Direct current electrical methods, and, in particular, the technique known as vertical electrical sounding (VES), have been widely used due to the high electrical conductivity and contrast of geological and hydrogeological units [38][39][40][41]. This technique consists of injecting an electric current into the ground through two electrodes (current electrodes also noted as A and B) and measuring the voltage difference through two other electrodes (potential electrodes).…”