Lassabatere L. auteur aut IRD Peyneau P.E. auteur aut IRD Yilmaz D. auteur aut IRD Pollacco J. auteur aut IRD Fernández-Gálvez J. auteur aut IRD Latorre B. auteur aut IRD Moret-Fernández D. auteur aut IRD Di Prima S. auteur aut IRD Rahmati M. auteur aut IRD Stewart R.D. auteur aut IRD Abou Najm M. auteur aut IRD Hammecker Claude auteur aut IRD Angulo-Jaramillo R. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Sorptivity is a parameter of primary importance in the study of unsaturated flow in soils. This hydraulic parameter is required to model water infiltration into vertical soil profiles. Sorptivity can be directly estimated from the soil hydraulic functions (water retention and hydraulic conductivity curves), using the integral formulation of Parlange (1975). However, calculating sorptivity in this manner requires the prior determination of the soil hydraulic diffusivity and its numerical integration between initial and final saturation degrees, which may be difficult in some situations (e.g., coarse soil with diffusivity functions that are quasi-infinite close to saturation). In this paper, we present a procedure to compute sorptivity using a scaling parameter, cp, that corresponds to the sorptivity of a unit soil (i.e., unit values for all parameters and zero residual water content) that is utterly dry at the initial state and saturated at the final state. The cp parameter was computed numerically and analytically for five hydraulic models: delta (i.e., Green and Ampt), Brooks and Corey, van Genuchten-Mualem, van Genuchten-Burdine, and Kosugi. Based on the results, we proposed brand new analytical expressions for some of the models and validated previous formulations for the other models. We also tabulated the output values so that they can easily be used to determine the actual sorptivity value for any case. At the same time, our numerical results showed that the relation between cp and the hydraulic shape parameters strongly depends on the chosen model. These results highlight the need for careful selection of the proper model for the description of the water retention and hydraulic conductivity functions when estimating sorptivity. specialized 062 068 020 25 9 5083-5104 2021 1607-7938 https://www.documentation.ird.fr/hor/fdi:010083758 10.5194/hess-25-5083-2021 1607-7938 [F B010083758] https://www.documentation.ird.fr/hor/fdi:010083758 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2022-12/010083758.pdf IRD - Base Horizon / Pleins textes 2022-03-28 2025-02-24 fdi:010083758 fre