- 1Laboratoire de Géologie, Ecole Normale Supérieure, CNRS UMR 8538, Institut Pierre-Simon Laplace, PSL Research University, Paris, France
- 2Earth Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- 3Amsterdam Institute for Life and Environment (A-LIFE), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
Soil structure is nearly as important as soil texture in determining the soil hydraulic properties at the core scale. Soil structure was also shown to significantly affect runoff and drainage at ecosystem scale (Fatichi et al., 2020; Bonetti et al., 2021). However, its effect on vadose zone hydrology at 100 km scale — at which climate and land surface models are often run — remains unclear. Seminal works (Fatichi et al., 2020; Bonetti et al., 2021) found a small effect of soil structure at these large scales, but this has been linked to the nature of the subgrid parametrization of precipitation (or of soil hydraulic conductivity) in the employed models. Here, we evaluate the effect of soil structure on vadose zone hydrology in the ORCHIDEE land surface model, which models infiltration using a unique subgrid parametrization of soil hydraulic conductivity (Vereecken et al., 2019). In ORCHIDEE, we find a larger effect of soil structure on the water cycle than reported for OLAM (Fatichi et al., 2020). We link this to the subgrid variability of hydraulic conductivity in ORCHIDEE, which ensures that the structural modifications of soil hydraulic properties are activated at all rainfall rates. Finally, we discuss the perspectives for parametrizing the structural modifications of soil hydraulic properties at large scales using soil moisture observations.
Bonetti, S., Wei, Z., & Or, D. (2021). A framework for quantifying hydrologic effects of soil structure across scales. Communications Earth & Environment, 2 (1), 1–10. https://doi.org/10.1038/s43247-021-00180-0
Fatichi, S., Or, D., Walko, R., Vereecken, H., Young, M. H., Ghezzehei, T. A., Hengl, T., Kollet, S., Agam, N., & Avissar, R. (2020). Soil structure is an important omission in Earth System Models. Nature Communications, 11 (1), 522. https://doi.org/10.1038/s41467-020-14411-z
Vereecken, H., Weihermüller, L., Assouline, S., Šimůnek, J., Verhoef, A., Herbst, M., Archer, N., Mohanty, B., Montzka, C., Vanderborght, J., Balsamo, G., Bechtold, M., Boone, A., Chadburn, S., Cuntz, M., Decharme, B., Ducharne, A., Ek, M., Garrigues, S., … Xue, Y. (2019). Infiltration from the Pedon to Global Grid Scales: An Overview and Outlook for Land Surface Modeling. Vadose Zone Journal, 18 (1), 180191. https://doi.org/10.2136/vzj2018.10.0191
How to cite: Kiałka, F., Flores, O., Naudts, K., Luyssaert, S., and Guenet, B.: Effect of soil structure on vadose zone hydrology in the ORCHIDEE land surface model, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19175, https://doi.org/10.5194/egusphere-egu25-19175, 2025.
