Enhancing Time-Lapse Geoelectrical Models of Soil Moisture Dynamics with a-priori X-Ray CT Derived Information
M. Cimpoiasu, O. Kuras, T. Pridmore and S. Mooney
Event name: 25th European Meeting of Environmental and Engineering Geophysics
Session: Integrated Studies I
Publication date: 10 September 2019
Info: Extended abstract, PDF ( 746.99Kb )
Price: € 20
Developing a better understanding of soil hydraulic properties is of significant importance for such diverse fields as agriculture, soil and ecosystems management, civil engineering and geotechnics. Electrical Resistivity Tomography (ERT) and X-ray Computed Tomography (CT) are two state-of-the-art methodologies with great potential for applications in soil science. ERT allows time-lapse monitoring of solute transport. X-ray CT is sensitive to bulk density changes at high resolution. We monitored the infiltration of a KCl solution through a partly deionized water saturated undisturbed cylindrical soil column using ERT. Prior the infiltration, we scanned our sample and segmented the pore architecture out of the resulting X-ray radiograms. Based on pore characteristics such as size and connectivity, we split the pore volume into two distinct zones, percolating and non-percolating pores. Afterwards, we reconstructed non-percolating pore features within the ERT model mesh. By comparing the ERT inversion result, with or without the pore architectural information, we noticed a sensible improvement in how the electrical model is able to represent the fluid flow path. This result sets the scene for a new joint methodology, which constrains the geoelectrical interpretation of the subsoil moisture with soil structural information and its contribution to solution infiltration.