2012/02/01 by Damien Jougnot, Niklas Linde, A. Revil +1 · 116 citations
Chemistry · Earth and Planetary Sciences · Engineering · Environmental Science · Mathematics · Physics and Astronomy · #Characterisation of pore space in soil #Chemistry #Electrical resistivity and conductivity #Environmental science #Geophysical and Geoelectrical Methods #Hydraulic conductivity #Loam #Mathematics #Permeability (electromagnetism) #Physics #Porosity #Porous medium #Relative permeability #Saturation (graph theory) #Soil Moisture and Remote Sensing #Soil and Unsaturated Flow #Soil science #Soil water #Streaming current #Water retention #physics.geo-ph
paper · pdf · doi:10.2136/vzj2011.0086
published in Vadose Zone Journal 11(1) (Soil Science Society of America)
openalex publication_date 2012/02/01 · arxiv created 2012/09/27 · arxiv updated 2012/09/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Water movement in unsaturated soils gives rise to measurable electrical potential differences that are related to the flow direction and volumetric fluxes, as well as to the soil properties themselves. Laboratory and field data suggest that these so‐called streaming potentials may be several orders of magnitudes larger than theoretical predictions that only consider the influence of the relative permeability and electrical conductivity on the self potential (SP) data. Recent work has improved predictions somewhat by considering how the volumetric excess charge in the pore space scales with the inverse of water saturation. We present a new theoretical approach that uses the flux‐averaged excess charge, not the volumetric excess charge, to predict streaming potentials. We present relationships for how this effective excess charge varies with water saturation for typical soil properties using either the water retention or the relative permeability function. We find large differences between soil types and the predictions based on the relative permeability function display the best agreement with field data. The new relationships better explain laboratory data than previous work and allow us to predict the recorded magnitudes of the streaming potentials following a rainfall event in sandy loam, whereas previous models predict values that are three orders of magnitude too small. We suggest that the strong signals in unsaturated media can be used to gain information about fluxes (including very small ones related to film flow), but also to constrain the relative permeability function, the water retention curve, and the relative electrical conductivity function.