Saturated hydraulic conductivity estimation of layered soil in 1D from Beerkan Experiment

In the last decade, the development of methodologies based on Beerkan infiltration (ring or disk infiltrometry technique with null constant water head) analysis allows today to estimate the hydraulic properties of surface soils with increasing accuracy. In particular, the 3D model of Haverkamp et al. (1994) and its two-term (BEST methods) and four-term (4T) expansions (Moret-Fernández et al., 2020) have demonstrated their robustness. The analysis of the transient part of cumulative Beerkan infiltration allows the simultaneous estimation of the sorptivity S and the hydraulic conductivity at saturation Ks. Very recently presented, the sequential analysis (SAI) of Beerkan data (Moret and Fernandez et al., 2021) applied to stratified soils columns allows delimiting the part of the Beerkan infiltration curve governed by the upper layer and estimating its thickness. This approach opens new perspectives for using Beerkan water infiltration, especially for estimating the conductivity of the underlying porous medium. Numerical Beerkan infiltration of layered soils combination in 1D were produced using van Genuchten-Mualem model and Hydrus 1D software.  Numerical curves were subject to SAI method to estimate the upper horizon soil hydraulic properties and the regime state of the infiltration flow allowed the estimation. Therefore, it is possible under certain assumptions to estimate the hydraulic conductivity of the underlying soil in 1D. This is the first step towards the determination of stratified soils hydraulic properties. This approach will allow new theoretical development for the extension to three-dimensional water infiltration into layered soils and relative hydraulic characterization of soil layering.

Moret-Fernández, D., Latorre, B., López, M.V., Pueyo, Y., Lassabatere, Angulo-Jaramillo, R., Rahmati,M., Tormo, J., Nicolu, J.M. (2020). Three- and four-term approximate expansions of the Haverkamp formulation to estimate soil hydraulic properties from disc infiltrometer measurements. Hydrological Processes, 34 (26), 5543-5556.  

Haverkamp, R., Ross, P. J., Smettem, K. R. J., & Parlange, J. Y. (1994). Three‐dimensional analysis of infiltration from the disc infiltrometer: 2. Physically based infiltration equation. Water Resources Research, 30(11), 2931-2935.

Moret-Fernández, D., Latorre, B., Lassabatere, L., Di Prima, S., Castellini, M., Yilmaz, D., & Angulo-Jaramilo, R. (2021). Sequential infiltration analysis of infiltration curves measured with disc infiltrometer in layered soils. Journal of Hydrology, 126542.