A note on the methods for determining soil water diffusivity

Soil Research ◽  
1982 ◽  
Vol 20 (1) ◽  
pp. 61
Author(s):  
HS Acharya
Keyword(s):  
Quadratic Programming ◽  
Soil Water ◽  
Water Distribution ◽  
Soil Column ◽  
Experimental Methods ◽  
Soil Columns ◽  
Method Of Calculation ◽  
Water Diffusivity ◽  
Horizontal Infiltration

In experimental methods for determination of soil water diffusivity using the water distribution from horizontal infiltration into a soil column, hand smoothing of the experimentally obtained distribution introduces uncertainties in the calculations. A method of calculation involving techniques of quadratic programming has been used to minimize the possible errors caused by inhomogeneous packing of the horizontal soil columns. Examples are given to illustrate the method of calculations.

Development of a soil water dispersion index (SOWADIN) for testing the effectiveness of soil-wetting agents

Soil Research ◽  
1989 ◽  
Vol 27 (1) ◽  
pp. 17 ◽  
Author(s):  
Y Sawada ◽  
LAG Aylmore ◽  
JM Hainsworth
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Water Distribution ◽  
Soil Column ◽  
Water Repellent ◽  
Computer Assisted ◽  
Dispersion Index ◽  
Soil Columns ◽  
Water Dispersion ◽  
Soil Wetting

Computer-assisted tomography (CAT) applied to gamma-ray attenuation measurements has been used to develop an index termed the soil water dispersion index (SOWADIN), which describes quantitatively the amount and distribution of water in soil columns. The index, which is determined by classifying pixels in a scanned slice into three categories according to their attenuation coefficients, contains two numerical values. The first value corresponds to the water content of the scanned slice and the second value is a measure of the dispersion of the water throughout the slice. Artificially wetted zones were created in soil columns to give one-third of the scanned layer wetted with various patterns of wetted-area distribution. The SOWADIN values obtained accurately reflected the differences in water distribution associated with the different patterns. Application of SOWADIN to columns of a water-repellent sand before and after treatment with a soil-wetting agent clearly illustrates both the increase in water content and improvement in water distribution in the soil column following treatment.

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.

Uptake of water from a Kandosol subsoil: I. Determination of soil water diffusivity

2012 ◽  
Vol 368 (1-2) ◽  
pp. 483-492 ◽  
Author(s):  
David M. Deery ◽  
John B. Passioura ◽  
Jason R. Condon ◽  
Asitha Katupitiya
Keyword(s):  
Soil Water ◽  
Water Diffusivity

Mobility of a Polyether Trisiloxane Surfactant in Soil: Soil/Water Distribution Coefficients and Leaching in a Soil Column

2016 ◽  
Vol 227 (2) ◽  
Author(s):  
Amandine Michel ◽  
Conrad Dietschweiler ◽  
Martina Böni ◽  
Michael Burkhardt ◽  
Heinz-Jürgen Brauch ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Distribution ◽  
Soil Column ◽  
Distribution Coefficients ◽  
Soil Water Distribution

Capillary Conductivity and Soil Water Diffusivity Values from Vertical Soil Columns 1

1968 ◽  
Vol 60 (6) ◽  
pp. 605-610 ◽  
Author(s):  
W. J. Flocker ◽  
M. Yamaguchi ◽  
D. R. Nielsen
Keyword(s):  
Soil Water ◽  
Soil Columns ◽  
Water Diffusivity

Influence of soil bulk density on horizontal water infiltration

Soil Research ◽  
1977 ◽  
Vol 15 (1) ◽  
pp. 83 ◽  
Author(s):  
AK Sharda
Keyword(s):  
Bulk Density ◽  
Soil Water ◽  
Soil Bulk Density ◽  
Water Infiltration ◽  
Silty Clay ◽  
Soil Columns ◽  
Silty Clay Loam ◽  
Infiltration Rates ◽  
Water Diffusivity ◽  
Relative Water

Studies were conducted on soil columns of a silty clay loam packed at bulk densities of 1200, 1300 and 1400 kg/m3 to evaluate the influence of soil bulk density on water infiltration in the horizontal direction. Soil water diffusivity values were obtained by reversing the iterative procedure of Philip. A reduction to less than 25% in soil water diffusivity occurred near saturation with the increase in soil bulk density, but the influence of soil bulk density decreased with the decrease in relative water content. Lengths of infiltration, cumulative influx and infiltration rates also reduced markedly with the increase in soil bulk density from 1200 kg/m to 1400 kg/m3.

Soil Water Diffusivity from Horizontal Infiltration

1968 ◽  
Vol 32 (1) ◽  
pp. 6-11 ◽  
Author(s):  
F. D. Whisler ◽  
A. Klute ◽  
D. B. Peters
Keyword(s):  
Soil Water ◽  
Water Diffusivity ◽  
Horizontal Infiltration

Determination of Technetium and Selenium Transport Properties in Laboratory Soil Columns

1988 ◽  
Vol 127 ◽  
Author(s):  
J. A. Del Debbio ◽  
T. R. Thomas
Keyword(s):  
Transport Properties ◽  
Soil Column ◽  
Retardation Factor ◽  
Soil Columns ◽  
Water Contact ◽  
Near Surface ◽  
One Dimensional ◽  
High Level ◽  
Water Saturated

ABSTRACTLaboratory studies are being conducted to measure the transport properties of various radionuclide species through soil columns. The studies are being conducted to support evaluations for potential near-surface disposal of high-level radioactive waste (HLW) calcine stored at the Idaho National Engineering Laboratory. The data will be used to model radionuclide transport through the vadose (unsaturated) zone of the site under various water-contact scenarios. Retardation factors and dispersion coefficients for technetium and selenium species have been measured in water-saturated soil columns made up of sediments taken from 12 and 35 meters below the surface. A one-dimensional, convective-dispersive, solute-transport equation was fitted to column effluent data by optimizing three parameters (retardation factor, dispersion coefficient and pulse time) using a non-linear, least-squares fitting routine. The data indicated no retardation of the pertechnetate ion (TcO4-)and selenate ion (SeO4-) and a large retardation of the selenite ion (SeO3-) relative to water transport through the soil column.

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