Articles | Volume 18, issue 19
https://doi.org/10.5194/gmd-18-6921-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gmd-18-6921-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Fitting the junction model and other parameterizations for the unsaturated soil hydraulic conductivity curve: KRIAfitter version 1.0
Gerrit Huibert de Rooij
CORRESPONDING AUTHOR
Dept. Soil System Science, Helmholtz Centre for Environmental Research – UFZ, 06120 Halle, Germany
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The way infiltrating water moves in soil affects vegetation as well as groundwater recharge. This flow of soil water is captured by a mathematical function that covers all water contents from very dry to water-saturated. We tested several such functions for different soils and climates to see how model-calculated water fluxes are affected. Luckily, the effects of weather and the soil are much more important than the choice of the mathematical function.
Gerrit Huibert de Rooij
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The way soils capture infiltrating water affects crops and natural vegetation as well as groundwater recharge. This retention of soil water is captured by a mathematical function that covers all water contents from very dry to water-saturated. Unfortunately, data in the dry range are often absent or unreliable. I modified an earlier function to be more robust in the absence of dry-range data, and present a computer program to estimate the parameters of the new function.
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Export of dissolved organic carbon (DOC) from riparian zones (RZs) is an important yet poorly understood component of the catchment carbon budget. This study chemically and spatially classifies DOC source zones within a RZ of a small catchment to assess DOC export patterns. Results highlight that DOC export from only a small fraction of the RZ with distinct DOC composition dominates overall DOC export. The application of a spatial, topographic proxy can be used to improve DOC export models.
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The way soils capture infiltrating water affects crops and natural vegetation and groundwater recharge. This retention of soil water is described by a mathematical function that covers all water contents from very dry to water saturated. We combined two existing lines of research to improve the behaviour of a popular function for very dry and very wet conditions. Our new function could handle a wider range of conditions than earlier curves. We provide fits to a wide range of soils.
Asha Nambiar and Gerrit Huibert de Rooij
EGUsphere, https://doi.org/10.5194/egusphere-2025-412, https://doi.org/10.5194/egusphere-2025-412, 2025
Short summary
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The way infiltrating water moves in soil affects vegetation as well as groundwater recharge. This flow of soil water is captured by a mathematical function that covers all water contents from very dry to water-saturated. We tested several such functions for different soils and climates to see how model-calculated water fluxes are affected. Luckily, the effects of weather and the soil are much more important than the choice of the mathematical function.
Gerrit Huibert de Rooij
Hydrol. Earth Syst. Sci., 26, 5849–5858, https://doi.org/10.5194/hess-26-5849-2022, https://doi.org/10.5194/hess-26-5849-2022, 2022
Short summary
Short summary
The way soils capture infiltrating water affects crops and natural vegetation as well as groundwater recharge. This retention of soil water is captured by a mathematical function that covers all water contents from very dry to water-saturated. Unfortunately, data in the dry range are often absent or unreliable. I modified an earlier function to be more robust in the absence of dry-range data, and present a computer program to estimate the parameters of the new function.
Benedikt J. Werner, Oliver J. Lechtenfeld, Andreas Musolff, Gerrit H. de Rooij, Jie Yang, Ralf Gründling, Ulrike Werban, and Jan H. Fleckenstein
Hydrol. Earth Syst. Sci., 25, 6067–6086, https://doi.org/10.5194/hess-25-6067-2021, https://doi.org/10.5194/hess-25-6067-2021, 2021
Short summary
Short summary
Export of dissolved organic carbon (DOC) from riparian zones (RZs) is an important yet poorly understood component of the catchment carbon budget. This study chemically and spatially classifies DOC source zones within a RZ of a small catchment to assess DOC export patterns. Results highlight that DOC export from only a small fraction of the RZ with distinct DOC composition dominates overall DOC export. The application of a spatial, topographic proxy can be used to improve DOC export models.
Gerrit Huibert de Rooij, Juliane Mai, and Raneem Madi
Hydrol. Earth Syst. Sci., 25, 983–1007, https://doi.org/10.5194/hess-25-983-2021, https://doi.org/10.5194/hess-25-983-2021, 2021
Short summary
Short summary
The way soils capture infiltrating water affects crops and natural vegetation and groundwater recharge. This retention of soil water is described by a mathematical function that covers all water contents from very dry to water saturated. We combined two existing lines of research to improve the behaviour of a popular function for very dry and very wet conditions. Our new function could handle a wider range of conditions than earlier curves. We provide fits to a wide range of soils.
Cited articles
Abramowitz, M. and Stegun, I. A.: Handbook of mathematical functions. With formulas, graphs, and mathematical tables, National Bureau of Standards, Dover edition, New York, USA, ISBN-10 0486612724, ISBN-13 9780486612720, 1964.
Assouline, S.: A model for soil relative hydraulic conductivity based on the water retention characteristic curve, Water Resour. Res., 37, 265–271, https://doi.org/10.1029/2000WR900254, 2001.
Bittelli, M. and Flury, M.: Errors in water retention curves determined with pressure plates, Soil Sci. Soc. Am. J., 73, 1453–1460, https://doi.org/10.2136/sssaj2008.0082, 2009.
Brooks, R. H. and Corey, A. T.: Hydraulic properties of porous media, Colorado State Univ., Hydrology Paper No. 3, 27 pp., 1964.
Brutsaert, W.: Hydrology. An introduction, Cambridge University Press, Cambridge, UK, ISBN-10 0521824796, ISBN-13 978-0521824798, 2005.
Dane, J. H. and Hopmans, J. W.: Pressure plate extractor, in: Methods of soil analysis. Part 4. Physical methods, edited by: Dane, J. H. and Topp, G. C., Soil Science Society of America, Madison, Wisconsin, USA, 688-690, https://doi.org/10.2136/SSSAbookser5.4, 2002.
de Jong van Lier, Q., Abreu de Melo, M. L., and Rodrigues Pinheiro, E. A.: Stochastic analysis of plant available water estimates and soil water balance components simulated by a hydrological model, Vadose Zone J., 23e20306, https://doi.org/10.1002/vzj2.20306, 2024.
de Rooij, G.: Fitting the junction model and other models for the unsaturated hydraulic conductivity curve: KRIAfitter, Zenodo [code], https://doi.org/10.5281/zenodo.14047941, 2024b.
de Rooij, G.: Fitting the parameters of the RIA parameterization of the soil water retention curve (2.0), Zenodo [code], https://doi.org/10.5281/zenodo.6491978, 2024c.
de Rooij, G.: Observed soil water retention and soil hydraulic conductivity data and fits to those data by RIAfitter and KRIAfitter, Zenodo [data], https://doi.org/10.5281/zenodo.14051087, 2024d.
de Rooij, G. H.: Technical note: A sigmoidal soil water retention curve without asymptote that is robust when dry-range data are unreliable, Hydrol. Earth Syst. Sci., 26, 5849–5858, https://doi.org/10.5194/hess-26-5849-2022, 2022.
de Rooij, G. H.: Averaging or adding domain conductivities to calculate the unsaturated soil hydraulic conductivity, Vadose Zone J., e20329, https://doi.org/10.1002/vzj2.20329, 2024a.
de Rooij, G. H., Mai, J., and Madi, R.: Sigmoidal water retention function with improved behaviour in dry and wet soils, Hydrol. Earth Syst. Sci., 25, 983–1007, https://doi.org/10.5194/hess-25-983-2021, 2021.
Dorsey, N. E.: Properties of ordinary water-substance, Reinhold Publishing, OCLC Number/Unique Identifier: 1081744493, 1940.
Duan, Q., Sorooshian, S., and Gupta, V.: Effective and efficient global optimization for conceptual rainfall-runoff models, Water Resour. Res., 28, 1015–1031, https://doi.org/10.1029/91WR02985, 1992.
Duan, Q., Sorooshian, S., and Gupta, V.: Optimal use of the SCE-UA global optimization method for calibrating watershed models, J. Hydrol., 158, 265–284, https://doi.org/10.1016/0022-1694(94)90057-4, 1994.
Duan, Q. Y., Gupta, V. K., and Sorooshian, S.: Shuffled complex evolution approach for effective and efficient global minimization, J. Optimization Theory and Applications, 76, 501–521, https://doi.org/10.1007/BF00939380, 1993.
Hurvich, C. M. and Tsai, C.-L.: Regression and time series model selection in small samples, Biometrika, 76, 297–307, https://doi.org/10.1093/biomet/76.2.297, 1989.
Ippisch, O., Vogel, H.-J., and Bastian, P.: Validity limits for the van Genuchten-Mualem model and implications for parameter estimation and numerical simulation, Adv. Water Resources, 29, 1780–1789, https://doi.org/10.1016/j.advwatres.2005.12.011, 2006.
Kosugi, K.: General model for unsaturated hydraulic conductivity for soils with lognormal pore-size distribution, Soil Sci. Soc. Am. J., 63, 270–277, https://doi.org/10.2136/sssaj1999.03615995006300020003x, 1999.
Madi, R., de Rooij, G. H., Mielenz, H., and Mai, J.: Parametric soil water retention models: a critical evaluation of expressions for the full moisture range, Hydrol. Earth Syst. Sci., 22, 1193–1219, https://doi.org/10.5194/hess-22-1193-2018, 2018.
Mualem, Y.: A new model for predicting the hydraulic conductivity of unsaturated porous media, Water Resour. Res., 12, 513–521, https://doi.org/10.1029/WR012i003p00513, 1976.
Or, D. and Tuller, M.: Flow in unsaturated fractured porous media: Hydraulic conductivity of rough surfaces, Water Resour Res., 36, 1165–1177, https://doi.org/10.1029/2000WR900020, 2000.
Peters, A.: Simple consistent models for water retention and hydraulic conductivity in the complete moisture range, Water Resour. Res., 49, 6765–6780, https://doi.org/10.1002/wrcr.20548, 2013.
Peters, A.: Reply to comment by S. Iden and W. Durner on `Simple consistent models for water retention and hydraulic conductivity in the complete moisture range', Water Resour. Res., 50, 7535–7539, https://doi.org/10.1002/2014WR016107, 2014.
Peters, A. and Durner, W.: A simple model for describing hydraulic conductivity in unsaturated porous media accounting for film and capillary flow, Water Resour. Res., 44, W11417, https://doi.org/10.1029/2008WR007136, 2008.
Peters, A., Durner, W., and Wessolek, G.: Consistent parameter constraints for soil hydraulic functions, Advances in Water Resources, 34, 1352–1365, https://doi.org/10.1016/j.advwatres.2011.07.006, 2011.
Rossi, C. and Nimmo, J. R.: Modeling of soil water retention from saturation to oven dryness, Water Resour. Res., 30, 701–708, https://doi.org/10.1029/93WR03238, 1994.
Schneider, M. and Goss, K.-U.: Prediction of the water sorption term in air dry soils, Geoderma, 170, 64–69, https://doi.org/10.1016/j.geoderma.2011.10.008, 2012.
Timlin, D. J., Ahuja, L. R., Pachepsky, Ya., Williams, R. D:, Gimenez, D., and Rawls, W.: Use of Brooks-Corey parameters to improve estimates of saturated conductivity from effective porosity, Soil Sci. Soc. Am. J., 63, 1086–1092, https://doi.org/10.2136/sssaj1999.6351086x, 1999.
van Genuchten, M. Th.: A closed-form equation for predicting the hydraulic conductivity for unsaturated soils, Soil Sci. Soc. Am. J., 44, 892–898, https://doi.org/10.2136/sssaj1980.03615995004400050002x, 1980.
Weber, T. K. D., Durner, W., Streck, T., and Diamantopoulos, E.: A modular framework for modeling unsaturated soil hydraulic properties over the full moisture range, Water Resour. Res., 55, 4994–5011, https://doi.org/10.1029/2018WR024584, 2019.
Short summary
Water flows ever more slowly in soil when the soil dries out. This can be described by the conductivity curve that accounts for water filling up small spaces, sticking to grains in films, and water vapour diffusion. This paper introduces a relatively simple model for this curve that needs one fewer parameter than most others. It works well for most soils, but some need the extra parameter. The paper also presents a computer program to determine the parameter values of this and other models.
Water flows ever more slowly in soil when the soil dries out. This can be described by the...