Articles | Volume 25, issue 2
https://doi.org/10.5194/hess-25-1097-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/hess-25-1097-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Opinion article
| 
02 Mar 2021
Opinion article |
| 02 Mar 2021
| 02 Mar 2021
HESS Opinions: Unsaturated infiltration – the need for a reconsideration of historical misconceptions
Peter F. Germann
CORRESPONDING AUTHOR
Department of Geography, University of Bern, Bern, Switzerland
deceased, 6 December 2020
Editorial note to close the review process of the article “Unsaturated infiltration: from unproven capillary flow to viscous flow" by Peter F. Germann.
Peter Germann submitted the first version of this opinion paper on 26 October 2020 to HESS. Together with two other scientists, John R. Nimmo kindly accepted to review this work in early November. Shortly after, I was shocked and deeply saddened to learn that Peter Germann had passed away rather suddenly on 6 December 2020 in Bern. While I succeeded in informing two reviewers, I did not manage to reach John Nimmo because he had retired in the meantime, and his official email account was switched off. As a result, John Nimmo reviewed the manuscript without knowing about Peter Germann’s death and submitted his comment on 19 January 2021.
I am very grateful to Keith Beven, who kindly offered to address John Nimmo’s insightful comments in the revised and consequently accepted manuscript and to add a preface in memoriam of Peter Germann’s life and scientific legacy.
Erwin Zehe, Executive Editor of HESS
Related authors
Massimiliano Schwarz, Filippo Giadrossich, Peter Lüscher, and Peter F. Germann
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2017-761, https://doi.org/10.5194/hess-2017-761, 2018
Preprint withdrawn
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Vegetation strongly influences the hydrology of hillslopes that are important for the mitigation of flood risks. In this work we present a new conceptual model that aims to link the effect of tree roots combined to the preferential flow of water. We use data from field experiments, coupled to tree position and dimension for the quantification of water preferential flow patches of a vegetated hillslope, considering topography and soil profile characteristics.
Massimiliano Schwarz, Filippo Giadrossich, Peter Lüscher, and Peter F. Germann
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2017-761, https://doi.org/10.5194/hess-2017-761, 2018
Preprint withdrawn
Short summary
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Vegetation strongly influences the hydrology of hillslopes that are important for the mitigation of flood risks. In this work we present a new conceptual model that aims to link the effect of tree roots combined to the preferential flow of water. We use data from field experiments, coupled to tree position and dimension for the quantification of water preferential flow patches of a vegetated hillslope, considering topography and soil profile characteristics.
Related subject area
Subject: Vadose Zone Hydrology | Techniques and Approaches: Theory development
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Hydro-pedotransfer functions: A roadmap for future development
Prediction of the absolute hydraulic conductivity function from soil water retention data
Mixed formulation for an easy and robust numerical computation of sorptivity
Signal contribution of distant areas to cosmic-ray neutron sensors – implications for footprint and sensitivity
Technical note: A sigmoidal soil water retention curve without asymptote that is robust when dry-range data are unreliable
Compaction effects on evaporation and salt precipitation in drying porous media
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Hysteresis in soil hydraulic conductivity as driven by salinity and sodicity – a modeling framework
Sigmoidal water retention function with improved behaviour in dry and wet soils
The challenges of an in situ validation of a nonequilibrium model of soil heat and moisture dynamics during fires
Anatomy of the 2018 agricultural drought in the Netherlands using in situ soil moisture and satellite vegetation indices
Beyond Perrault's experiments: repeatability, didactics and complexity
Mechanisms of consistently disjunct soil water pools over (pore) space and time
Energy states of soil water – a thermodynamic perspective on soil water dynamics and storage-controlled streamflow generation in different landscapes
Hydrological characterization of cave drip waters in a porous limestone: Golgotha Cave, Western Australia
Soil water stable isotopes reveal evaporation dynamics at the soil–plant–atmosphere interface of the critical zone
Soil water migration in the unsaturated zone of semiarid region in China from isotope evidence
Governing equations of transient soil water flow and soil water flux in multi-dimensional fractional anisotropic media and fractional time
A thermodynamic formulation of root water uptake
Soil–aquifer phenomena affecting groundwater under vertisols: a review
How effective is river restoration in re-establishing groundwater–surface water interactions? – A case study
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Relations between macropore network characteristics and the degree of preferential solute transport
Impacts of conservation tillage on the hydrological and agronomic performance of Fanya juus in the upper Blue Nile (Abbay) river basin
Averaged water potentials in soil water and groundwater, and their connection to menisci in soil pores, field-scale flow phenomena, and simple groundwater flows
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Hydrol. Earth Syst. Sci., 28, 1897–1914, https://doi.org/10.5194/hess-28-1897-2024, https://doi.org/10.5194/hess-28-1897-2024, 2024
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Andre Peters, Sascha C. Iden, and Wolfgang Durner
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While various expressions for the water retention curve are commonly compared, the capillary conductivity model proposed by Mualem is widely used but seldom compared to alternatives. We compare four different capillary bundle models in terms of their ability to fully predict the hydraulic conductivity. The Mualem model outperformed the three other models in terms of predictive accuracy. Our findings suggest that the widespread use of the Mualem model is justified.
Tobias Karl David Weber, Lutz Weihermüller, Attila Nemes, Michel Bechtold, Aurore Degré, Efstathios Diamantopoulos, Simone Fatichi, Vilim Filipović, Surya Gupta, Tobias L. Hohenbrink, Daniel R. Hirmas, Conrad Jackisch, Quirijn de Jong van Lier, John Koestel, Peter Lehmann, Toby R. Marthews, Budiman Minasny, Holger Pagel, Martine van der Ploeg, Simon Fiil Svane, Brigitta Szabó, Harry Vereecken, Anne Verhoef, Michael Young, Yijian Zeng, Yonggen Zhang, and Sara Bonetti
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Pedotransfer functions (PTFs) are used to predicts parameters of models describing the hydraulic properties of soils. The appropriateness of these predictions critically rely on the nature of the datasets for training the PTFs as well the physical comprehensiveness of the models. This roadmap papers is addressed at PTF developers and users, and critically reflects the utility and future of PTFs. To this end, we present a manifesto aiming at a paradigm shift in PTFs research.
Andre Peters, Tobias L. Hohenbrink, Sascha C. Iden, Martinus Th. van Genuchten, and Wolfgang Durner
Hydrol. Earth Syst. Sci., 27, 1565–1582, https://doi.org/10.5194/hess-27-1565-2023, https://doi.org/10.5194/hess-27-1565-2023, 2023
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Hydrol. Earth Syst. Sci., 27, 895–915, https://doi.org/10.5194/hess-27-895-2023, https://doi.org/10.5194/hess-27-895-2023, 2023
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Sorptivity is one of the most important parameters for quantifying water infiltration into soils. In this study, we propose a mixed formulation that avoids numerical issues and allows for the computation of sorptivity for all types of models chosen for describing the soil hydraulic functions and all initial and final conditions. We show the benefits of using the mixed formulation with regard to modeling water infiltration into soils.
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Gerrit Huibert de Rooij
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William J. Massman
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Stefano Barontini and Matteo Settura
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Erwin Zehe, Ralf Loritz, Conrad Jackisch, Martijn Westhoff, Axel Kleidon, Theresa Blume, Sibylle K. Hassler, and Hubert H. Savenije
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Hydrol. Earth Syst. Sci., 22, 977–988, https://doi.org/10.5194/hess-22-977-2018, https://doi.org/10.5194/hess-22-977-2018, 2018
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Matthias Sprenger, Doerthe Tetzlaff, and Chris Soulsby
Hydrol. Earth Syst. Sci., 21, 3839–3858, https://doi.org/10.5194/hess-21-3839-2017, https://doi.org/10.5194/hess-21-3839-2017, 2017
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We sampled the isotopic composition in the top 20 cm at four different sites in the Scottish Highlands at 5 cm intervals over 1 year. The relationship between the soil water isotopic fractionation and evapotranspiration showed a hysteresis pattern due to a lag response to onset and offset of the evaporative losses. The isotope data revealed that vegetation had a significant influence on the soil evaporation with evaporation being double from soils beneath Scots pine compared to heather.
Yonggang Yang and Bojie Fu
Hydrol. Earth Syst. Sci., 21, 1757–1767, https://doi.org/10.5194/hess-21-1757-2017, https://doi.org/10.5194/hess-21-1757-2017, 2017
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M. Levent Kavvas, Ali Ercan, and James Polsinelli
Hydrol. Earth Syst. Sci., 21, 1547–1557, https://doi.org/10.5194/hess-21-1547-2017, https://doi.org/10.5194/hess-21-1547-2017, 2017
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In this study dimensionally consistent governing equations of continuity and motion for transient soil water flow and water flux in fractional time and in fractional multiple space dimensions in anisotropic media are developed. By the introduction of the Brooks–Corey constitutive relationships, an explicit form of the equations is obtained. The developed governing equations, in their fractional time but integer space forms, show behavior consistent with the previous experimental observations.
Anke Hildebrandt, Axel Kleidon, and Marcel Bechmann
Hydrol. Earth Syst. Sci., 20, 3441–3454, https://doi.org/10.5194/hess-20-3441-2016, https://doi.org/10.5194/hess-20-3441-2016, 2016
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This theoretical paper describes the energy fluxes and dissipation along the flow paths involved in root water uptake, an approach that is rarely taken. We show that this provides useful additional insights for understanding the biotic and abiotic impediments to root water uptake. This approach shall be applied to explore efficient water uptake strategies and help locate the limiting processes in the complex soil–plant–atmosphere system.
D. Kurtzman, S. Baram, and O. Dahan
Hydrol. Earth Syst. Sci., 20, 1–12, https://doi.org/10.5194/hess-20-1-2016, https://doi.org/10.5194/hess-20-1-2016, 2016
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Vertisols are cracking clayey, arable soils that often overlay groundwater reservoirs. The soil cracks enable flow that bypasses soil blocks, which results in both relatively fresh recharge of the underlying groundwater and contamination with reactive contaminants. These special phenomena, as well as unique mechanism of salinization after cultivation and relative resilience to contamination by nitrate typical to groundwater under vertisols, are reviewed in this study.
A.-M. Kurth, C. Weber, and M. Schirmer
Hydrol. Earth Syst. Sci., 19, 2663–2672, https://doi.org/10.5194/hess-19-2663-2015, https://doi.org/10.5194/hess-19-2663-2015, 2015
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This study investigates the effects of river restoration on groundwater–surface water interactions in a losing urban stream. Investigations were performed using Distributed Temperature Sensing (DTS). The results indicate that the highest surface water downwelling occurred at the tip of a gravel island newly installed during river restoration, leading to the conclusion that in this specific setting, river restoration was effective in locally enhancing groundwater–surface water interactions.
F. Ries, J. Lange, S. Schmidt, H. Puhlmann, and M. Sauter
Hydrol. Earth Syst. Sci., 19, 1439–1456, https://doi.org/10.5194/hess-19-1439-2015, https://doi.org/10.5194/hess-19-1439-2015, 2015
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Soil moisture was observed along a strong semi-arid climatic gradient in a Mediterranean karst area. Soil moisture data and soil hydraulic modelling with Hydrus-1D revealed a strong dependency of percolation fluxes with rainfall amounts and intensity during heavy rainfall events. Spatial and temporal extrapolation of the model illustrated the high variability of seasonal percolation amounts among single years and showed strong correlations between soil depth and potential groundwater recharge.
M. Larsbo, J. Koestel, and N. Jarvis
Hydrol. Earth Syst. Sci., 18, 5255–5269, https://doi.org/10.5194/hess-18-5255-2014, https://doi.org/10.5194/hess-18-5255-2014, 2014
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The characteristics of the macropore network determine the potential for fast transport of solutes through soil. Such characteristics computed from 3-dimensional X-ray tomography images were combined with measured solute breakthrough curves and near-saturated hydraulic conductivities. At a given flow rate, smaller macroporosities, poorer local connectivity of the macropore network and smaller near-saturated hydraulic conductivities resulted in a greater degree of preferential transport.
M. Temesgen, S. Uhlenbrook, B. Simane, P. van der Zaag, Y. Mohamed, J. Wenninger, and H. H. G. Savenije
Hydrol. Earth Syst. Sci., 16, 4725–4735, https://doi.org/10.5194/hess-16-4725-2012, https://doi.org/10.5194/hess-16-4725-2012, 2012
G. H. de Rooij
Hydrol. Earth Syst. Sci., 15, 1601–1614, https://doi.org/10.5194/hess-15-1601-2011, https://doi.org/10.5194/hess-15-1601-2011, 2011
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This is the last paper submitted by Peter Germann before he died in December 2020. Peter reviews the development of capillary flow theory since the work of Briggs (1897) and Richards (1931), who raised capillary flow to a soil hydrological dogma. Attempts to correct the dogma led to concepts of non-equilibrium flow, macropore flow, and preferential flow during infiltration. Viscous film flow is proposed as an alternative approach to capillarity-driven flow during unsaturated infiltration.
This is the last paper submitted by Peter Germann before he died in December 2020. Peter reviews...
