A Theoretical Approach to Near Surface Pedophysical Permittivity Models

As geophysical approaches to investigating the shallow near surface, e.g., for agricultural, environmental or cultural applications, are increasing, the need for robust interpretative frameworks that enable converting geophysical data to quantitative information on subsurface properties equally rises. Despite well-established insight into relationships between electrical conductivity (σ) or relative permittivity (εr) of rocks, ambiguity remains about how these relationships and insights can be transferred to soils (Romero-Ruiz et al., 2018; Wunderlich et al., 2013). For pedological applications, successful interpretation of geophysical data for soil property quantification hinges on correct use of available pedophysical models (extending on their petrophysical counterparts to increase validity in unconsolidated sediments), which often are limited in their predictive capacity. Note that such models differ from pedotransfer functions (PTFs), which target prediction of soil hydraulic properties, such as water retention characteristics, based on soil properties that can be described more easily (e.g., soil texture, organic carbon and bulk density (Vereecken et al. 1989)).