scholarly journals Prediction of Unsaturated Relative Hydraulic Conductivity from Kosugi's Water Retention Function

2013 ◽  
Vol 19 ◽  
pp. 609-617 ◽  
Author(s):  
Paolo Nasta ◽  
Shmuel Assouline ◽  
John B. Gates ◽  
Jan W. Hopmans ◽  
Nunzio Romano
Keyword(s):  
Hydraulic Conductivity ◽  
Water Retention ◽  
Retention Function ◽  
Relative Hydraulic Conductivity

Enhanced Mualem-Van Genuchten Approach for Estimating Relative Soil Hydraulic Conductivity

2015 ◽  
Vol 725-726 ◽  
pp. 355-360 ◽  
Author(s):  
Vitaly Terleev ◽  
Vladimir Badenko ◽  
Inna Guseva ◽  
Wilfried Mirschel
Keyword(s):  
Hydraulic Conductivity ◽  
Water Retention ◽  
Soil Characteristics ◽  
Water Volume ◽  
Water Retention Capacity ◽  
Moisture Capacity ◽  
Theoretical Justification ◽  
Retention Capacity ◽  
Relative Water ◽  
Relative Hydraulic Conductivity

New theoretical justification for the function of soil differential moisture capacity (dependence of the relative water volume content on the capillary pressure) and its antiderivative is presented. New method is based on the concept of capillarity and the lognormal distribution of the effective radii of pores. Relative hydraulic conductivity of soil is calculated with usage of these functions and Mualem's approach. Hydrophysical parameters have been interpreted and evaluated on the base of some physical and statistical soil characteristics. Also the approximation for functions of water-retention capacity and relative hydraulic conductivity of soil has been proposed.

scholarly journals Soil-hydrophysical information support of precise irrigation farming

2021 ◽  
Vol 2(26) ◽  
pp. 244-260
Author(s):  
V.V. Terleev ◽  
◽  
Ie. A. Dunaieva ◽  
R.S. Ginevsky ◽  
V.A. Lazarev ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Water Retention ◽  
Mathematical Formulation ◽  
Soil Layer ◽  
Water Retention Capacity ◽  
Hysteresis Phenomenon ◽  
Retention Capacity ◽  
Irrigation Rate ◽  
Relative Hydraulic Conductivity

The relevance of the study is determined by the demand for a physically adequate mathematical description of the interactions of water in the soil to develop a model of soil moisture dynamics as the intellectual core of resource-saving technologies for precise irrigation farming. The aim of the work is theoretical substantiation and mathematical formulation of the hydrophysical functions of the soil, taking into account hysteresis. A description of three systems of soil hydrophysical functions is given. To verify and compare the systems, computational experiments were carried out using both the package of original software and “3305 Ida silt loam (> 15 cm)” soil data from the authoritative literary source – the Mualem catalogue. The parameters of the functions were identified by the method of point approximation of the experimental data on the main branches of the hysteretic water-retention capacity. Using these parameters, we calculated (i) predictive estimates for the values of the function of relative hydraulic conductivity; (ii) scanning branches of the hysteretic water-retention capacity; (iii) precise irrigation rate. The hysteresis phenomenon is not typical for the hydraulic conductivity as a function of the volumetric water content in the soil. The original functions of System 3 are recommended for use. The advantages of the proposed method for calculating the precise irrigation rate are shown. The benefit of each system is that the functions forming this system, namely the water-retention capacity and the relative hydraulic conductivity of the soil, have a common set of parameters. For the type of soil considered, in case of using the identical value of pre-irrigation soil moisture (179 [cm3 · cm-3]), both for calculating the precision irrigation rate and according to the “traditional” method, when moistening 50 cm soil layer, the total unproductive water consumption at irrigation rate 555 [m3 · ha-1] can reach 0.029 [cm3 · cm-3] or 140 [m3 · ha-1] in the calculated layer. At the same time, when applying precision standards, an excess of free moisture is not formed. It shows additional opportunities not only to save water during irrigation, especially in arid regions, but also to reduce the leaching of nutrients and agrochemicals outside the calculated soil layer and, accordingly, to reduce the additional environmental load on the surrounding area.

scholarly journals Modeling of Hydrophysical Properties of the Soil as Capillary-Porous Media and Improvement of Mualem-Van Genuchten Method as a Part of Foundation Arrangement Research

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Vitaly Terleev ◽  
Aleksandr Nikonorov ◽  
Vladimir Badenko ◽  
Inna Guseva ◽  
Yulia Volkova ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Water Retention ◽  
Water Retention Capacity ◽  
Filter Coefficient ◽  
Theoretical Justification ◽  
Retention Capacity ◽  
Soil Hydraulic Conductivity ◽  
Water Capacity ◽  
Conductivity Function ◽  
Relative Hydraulic Conductivity

Within the concepts about the capillarity and the lognormal distribution of effective pore radii, a theoretical justification for function of differential water capacity and its antiderivative (function of water-retention capacity in form of a dependence of the soil volumetric water content on capillary pressure of the soil moisture) is presented. Using these functions, the ratio of soil hydraulic conductivity function to the filter coefficient is calculated. Approximations to functions describing the water-retention capacity and relative hydraulic conductivity of the soil have been suggested. Parameters of these functions have been interpreted and estimated with applying the physical and statistical indices of the soil.

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