EGU21-8126
https://doi.org/10.5194/egusphere-egu21-8126
EGU General Assembly 2021
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Root bio-hydro-mechanical reinforcement of unsaturated vegetated soil: experiments and modelling

Anthony Leung1, Davide Boldrin2,3, Ali Akbar Karimzadeh1, Zhaoyi Wu1, and Suriya Ganesan1
Anthony Leung et al.
  • 1Hong Kong University of Science and Technology, Civil and Environmental Engineering, Hong Kong (ceanthony@ust.hk)
  • 2James Hutton Institute, Dundee, U. K.
  • 3School of Science and Engineering, University of Dundee, Dundee, U. K.

Plant roots affect soil water regime through root-water uptake upon transpiration. This process induces soil matric suction, which affects soil hydraulic conductivity, soil shear strength and hence shallow soil stability. This is referred to as plant hydrological reinforcement in the soil bioengineering application. Recent experimental evidence put forward by the authors has demonstrated that plant hydrological reinforcement should not be exclusively limited to the effects of root-water uptake and plant transpiration. The presentation will provide some new evidence of other potential aspects of plant hydrological reinforcement, namely (1) root-induced changes in soil hydraulic properties, (2) root water-dependent bio-hydro-mechanical properties. In aspect (1), laboratory test results on how root growth dynamic alter the soil pore size distribution and hence affect both the soil water retention curve and hydraulic conductivity will be presented. To highlight the effects of these root-induced changes in soil properties on slope water regime and slope stability, numerical simulation employing a dual-permeability water transport model in unsaturated rooted soil will be discussed. In aspect (2), a new concept, hysteretic root water retention curve (relationship between root water content and root water potential), will be introduced with support of some preliminary data. How root water retention affects the root biomechanical properties including not only tensile strength and Young’s modulus that have received wide attention in the soil bioengineering literature but also breakage strain will be presented. New data will be provided in order to attempt to use root water content to explain the large variability of biomechanical properties observed in the literature.

How to cite: Leung, A., Boldrin, D., Karimzadeh, A. A., Wu, Z., and Ganesan, S.: Root bio-hydro-mechanical reinforcement of unsaturated vegetated soil: experiments and modelling, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8126, https://doi.org/10.5194/egusphere-egu21-8126, 2021.

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