Determination of Hydraulic Conductivity of Undisturbed Soil Column: a Measurement Accomplished with the Gamma Ray Transmission Technique

Gamma ray transmission for hydraulic conductivity measurement of undisturbed soil columns

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132007000200017 ◽

2007 ◽

Vol 50 (2) ◽

pp. 321-328 ◽

Cited By ~ 4

Author(s):

Anderson Camargo Moreira ◽

Otávio Portezan Filho ◽

Fábio Henrique Moraes Cavalcante ◽

Melayne Martins Coimbra ◽

Carlos Roberto Appoloni

Keyword(s):

Hydraulic Conductivity ◽

Gamma Ray ◽

Conductivity Measurement ◽

Nondestructive Method ◽

Soil Density ◽

Soil Columns ◽

Undisturbed Soil ◽

Transmission Technique ◽

Homogeneous Soil

This work had the objective to determine the Hydraulic Conductivity K(theta) function for different depth levels z, of columns of undisturbed soil, using the gamma ray transmission technique applied to the Sisson method. The results indicated a growing behavior for K(theta) and a homogeneous soil density, both in relation to the increase of the depth. The methodology of gamma ray transmission showed satisfactory results on the determination of the hydraulic conductivity in columns of undisturbed soil, besides being very reliable and a nondestructive method.

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Effects of Temperature Change on the Soil Water Characteristic Curve and a Prediction Model for the Mu Us Bottomland, Northern China

Water ◽

10.3390/w11061235 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1235

Author(s):

Xiaoying Qiao ◽

Shaoyang Ma ◽

Guixing Pan ◽

Guanglu Liu

Keyword(s):

Hydraulic Conductivity ◽

Prediction Model ◽

Soil Water ◽

Direct Measurement ◽

Empirical Formula ◽

Characteristic Curve ◽

Soil Column ◽

Distribution Model ◽

Undisturbed Soil ◽

Soil Water Characteristic Curve

The soil-water characteristic curve (SWCC) is the basis for obtaining the hydraulic conductivity parameters of a soil as well as for using soil water and heat transport models. At present, the curve can be obtained by two methods: by direct measurement and by empirical formula. Direct measurement is both difficult and time-consuming. By contrast, fitting the SWCC with a suitable empirical formula is stable and convenient. The van Genuchten (VG) model has the advantage of universal applicability due to its use of a statistical aperture distribution model for estimating hydraulic conductivity. This study selected the Mu Us Bottomland as a study area. Data on the water content and water potential of undisturbed soil from this site were obtained with a Ku-pF instrument and a self-designed soil column experiment with temperature settings of 13 °C, 18 °C, 23 °C, 27 °C, and 30 °C. The variation of four main parameters in the VG model with temperature was analyzed based on thermodynamic theory and considering the effect of temperature on soil capillary pressure via its effects on surface tension and contact angle. A prediction model for the soil-water characteristic curve of the Mu Us Bottomland was then constructed, and its applicability was further analyzed. The temperature dependence of the SWCC demonstrated here provides an important scientific basis for agricultural production, farmland water conservancy, and the design of soil and water conservation engineering projects.

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Water Phase Inclination Theory for Hydraulic Conductivity Determination of Vadose Zones in Shallow Water Table Systems

Iraqi Geological Journal ◽

10.46717/igj.54.2b.8ms-2021-08-28 ◽

2021 ◽

Vol 54 (2B) ◽

pp. 85-100

Author(s):

Arkan Radi Ali

Keyword(s):

Hydraulic Conductivity ◽

Shallow Water ◽

Linear Relationship ◽

Water Table ◽

Correlation Factor ◽

Water Phase ◽

Shallow Water Table ◽

Allowable Limit ◽

Undisturbed Soil

Water Phase Inclination is an innovative theory for hydraulic conductivity and determination of vadose zone overlying shallow water table systems. It was originated and analytically derived from Darcy's Law and based on some physio-mechanical properties of soil. Al-Musayab area of 176 Km2 at Mesopotamian region, mid-Iraq was undertaken as a case study. It consists of unconsolidated quaternary deposits and is usually finer-grained than the underlying pebbly sandstone with Mediterranean weather. The Experimental part was divided into field tests which include double ring infiltrometer tests, water table depth measurements and sampling of 32 undisturbed soil samples of surface layers scattered over the study area Whereas lab tests include; the falling and constant head permeability, grain size distribution (sieve and hydrometer analysis), soil specific gravity, direct shear tests and the measuring of Water Phase Inclinations. Angle \emptyset a glassy infiltration box is an experimental device that was manufactured to measure the Water Phase Inclination angle and aquifer simulation. It is found a generalized linear relationship between  and the angle of internal friction which is valid for   23.37 with correlation factor R² = 0.99 and both angles depend on soil texture. The k values estimated by WPI theory and that measured by traditional techniques offer a linear relationship with acceptable Root Mean Square Error equals 0.0642 < 0.1 the max allowable limit and correlation factor R² = 0.96, pointing out to the reliability and stability of the Water Phase Inclination results.

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Determination of the hydraulic conductivity function of grey Vertosol with soil column test

Heliyon ◽

10.1016/j.heliyon.2020.e05399 ◽

2020 ◽

Vol 6 (11) ◽

pp. e05399

Author(s):

Rajitha Shehan Udukumburage ◽

Chaminda Gallage ◽

Les Dawes ◽

Yilin Gui

Keyword(s):

Hydraulic Conductivity ◽

Soil Column ◽

Column Test ◽

Conductivity Function

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An improved drip infiltrometer measuring the near-saturated hydraulic conductivity: Pedotransfer development and macropore transport

10.5194/egusphere-egu2020-22667 ◽

2020 ◽

Author(s):

Bo Vangsø Iversen ◽

Michael Koppelgaard ◽

Ali M. Kotlar

Keyword(s):

Hydraulic Conductivity ◽

Root Zone ◽

Soil Column ◽

Saturated Hydraulic Conductivity ◽

Pedotransfer Functions ◽

Ceramic Plate ◽

Undisturbed Soil ◽

Flow Rates ◽

Spatially Distributed ◽

High Level

<p>The near-saturated hydraulic conductivity is an important parameter in relation to the analysis of heterogeneous transport in the soil macropore system. To a high degree, leaching of phosphorus out of the root zone takes place in the macropores either in a dissolved form or as phosphorus bound to colloids. In this work, a newly constructed and improved drip infiltrometer (DIM) is presented being able to measure the unsaturated hydraulic conductivity in the near-saturated range (i.e. in the range of matric potentials between -0.1 and 3 -kPa) on undisturbed soil columns (20 cm by 20 cm). The DIM is a modified version of the classical multistep system establishing gravity flow at decreasing flow rates. The procedure is that the soil column is placed on top of a ceramic plate. Five tensiometers measure the change in the matric potential a different flow rates applied by a drip-irrigation device mounted on the top of the column. By applying a certain inflow at the top and suction at the bottom of the sample, a steady state flow is established based on tensiometer readings showing a constant gradient along the soil sample. This allows the determination of the near-saturated hydraulic conductivity by applying Darcy&#8217;s equation. Compared to an earlier version of the infiltrometer, the instrument has been improved in several ways. This involves a high level of automation of the computer program controlling the analysis making it possible to setup a number of settings and constrains in order to optimize the analysis. Examples are given for newly developed pedotransfer functions predicting the saturated and near-saturated hydraulic conductivity. Results were used to model water transport in the vadose zone spatially distributed over Denmark using variation in the hydraulic properties as well as spatially distributed metrological data. Models results ended up with a map pointing out risk areas of macropore transport in relation to the leaching of phosphorus.</p>

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