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
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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
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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.
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Subject: Vadose Zone Hydrology | Techniques and Approaches: Theory development
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Yonggang Yang and Bojie Fu
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M. Levent Kavvas, Ali Ercan, and James Polsinelli
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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
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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
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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...
