scholarly journals Water Retention Curve, Water Diffusivity and Water Movement of Compacted Bentonite

1995 ◽  
Vol 35 (3) ◽  
pp. 129-137 ◽  
Author(s):  
Shinji Takeuchi ◽  
Keiji Hara ◽  
Masashi Nakano
Keyword(s):  
Water Retention ◽  
Water Movement ◽  
Water Retention Curve ◽  
Retention Curve ◽  
Compacted Bentonite ◽  
Water Diffusivity

Determination of soil water hydraulic parameters from infiltration data

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yan Gao ◽  
Kai Chang ◽  
Xuguang Xing ◽  
Jiaping Liang ◽  
Nian He ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Test Method ◽  
Water Retention Curve ◽  
Absorption Method ◽  
Retention Curve ◽  
Content Type ◽  
One Dimensional ◽  
Water Diffusivity

PurposeTraditional laboratory measurements of soil water diffusivity (D) and soil water retention curve (SWRC) are always time-consuming and labor-intensive. Therefore, this paper aims to present a simple and robust test method for determining D and SWRC without reducing accuracy.Design/methodology/approachIn this study, a D model of unsaturated soil was established based on Gardner–Russo model and then a combination of Gardner–Russo model with one-dimensional horizontal absorption method to obtain n and a parameters of Gardner–Russo model. One-dimensional horizontal absorption experiments on loam, silt loam and sandy clay loam were conducted to obtain the relationships between measured infiltration rate and cumulative infiltration with wetting front distance. Based on the obtained relationships, the measured infiltration data from the one-dimensional horizontal absorption tests were used to calculate n and a parameters and further constructing D and SWRC.FindingsBoth the calculated D and SWRC inversed from the infiltration data were in good agreement with the measured ones that obtained from the traditional horizontal absorption method and the centrifuge method, respectively. Error analysis indicated that only the infiltration data are enough to reliably synchronously determine D and SWRC.Originality/valueA simple and robust method is proposed for synchronous determination of soil water diffusivity and water retention curve.

scholarly journals Relating Hydraulic Conductivity Curve to Soil-Water Retention Curve Using a Fractal Model

Mathematics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 2201
Author(s):  
Carlos Fuentes ◽  
Carlos Chávez ◽  
Fernando Brambila
Keyword(s):  
Hydraulic Conductivity ◽  
Fractal Geometry ◽  
Water Retention ◽  
Water Movement ◽  
Darcy Law ◽  
Water Retention Curve ◽  
Hydrodynamic Characteristics ◽  
Soil Pressure ◽  
Retention Curve ◽  
Conductivity Curve

In the study of water transference in soil according to Darcy law, the knowledge of hydrodynamic characteristics, formed by the water retention curve θ(ψ), and the hydraulic conductivity curve K(ψ) are of great importance. The first one relates the water volumetric content (θ) with the water-soil pressure (ψ); the second one, the hydraulic conductivity (K) with the water-soil pressure. The objective of this work is to establish relationships between both curves using concepts of probability theory and fractal geometry in order to reduce the number of unknown functions. The introduction of four definitions used at the literature of the pore effective radius that is involve in the general model has permitted to establish four new specials models to predict the relative hydraulic conductivity. Some additional considerations related to the definitions of flow effective area and the tortuosity factor have allow us to deduce four classical models that are extensively used in different studies. In particular, we have given some interpretations of its empirical parameters in the fractal geometry context. The resulting functions for hydrodynamic characteristics can be utilized in many studies of water movement in the soil.

scholarly journals Dependence of the water retention curve of snow on snow characteristics

2012 ◽  
Vol 53 (61) ◽  
pp. 6-12 ◽  
Author(s):  
Satoru Yamaguchi ◽  
Kunio Watanabe ◽  
Takafumi Katsushima ◽  
Atsushi Sato ◽  
Toshiro Kumakura
Keyword(s):  
Grain Size ◽  
Snow Cover ◽  
Water Retention ◽  
Water Movement ◽  
Column Experiment ◽  
Water Retention Curve ◽  
Dry Density ◽  
Soil Physics ◽  
Retention Curve ◽  
Physics Model

AbstractThe water retention curve (WRC), which shows the relationship between the volumetric liquid water content,θv, and suction,h, is a fundamental part of the characterization of hydraulic properties. Therefore, the formulation of the WRC as a function of snow characteristics is essential for establishing a model of water movement through the snow cover. In this study, we measured the WRC of several snow samples, which had different characteristics (grain size, bulk dry density and grain type), using a gravity drainage column experiment and then analysed these data using the Van Genuchten soil physics model (VG model). The shape of the WRC depended strongly on both the sample grain size,d, and bulk dry density,ρ. Therefore, we introduced the parameterρ/dto model the WRC of snow. The relationships between the parametersαandnof the VG model andρ/dchange with grain type. For melt forms,α, which is related to the inverse value of the air-entry suction, increases quickly asρ/ddecreases, whereasn, which is related to the gradient ofθvvsh, increases withρ/d. Conversely, neither of these parameters of the VG model for rounded grains showed obvious dependence onρ/d. These results suggest that water movement through snow cover can be modelled using grain size, bulk dry density and grain type based on the soil physics model.

INFLUENCE OF SOIL MATRIX ON SOIL-WATER RETENTION CURVE AND HYDRAULIC CHARACTERISTICS

2017 ◽  
Vol 16 (4) ◽  
pp. 869-877
Author(s):  
Vasile Lucian Pavel ◽  
Florian Statescu ◽  
Dorin Cotiu.ca-Zauca ◽  
Gabriela Biali ◽  
Paula Cojocaru
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Water Retention Curve ◽  
Hydraulic Characteristics ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Soil Matrix ◽  
Retention Curve
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