نتایج جستجو برای: soil hydraulic parameters

تعداد نتایج: 769656  

2007
L. Ma P. Heilman L. R. Ahuja T. Meade R. S. Kanwar

Process-based agricultural system models require detailed description of soil hydraulic properties that are usually not available. The objectives of this study were to evaluate the sensitivity of model simulation results to variability in measured soil hydraulic properties and to compare simulation results using measured and default soil parameters. To do so, we measured soil water retention cu...

ژورنال: علوم آب و خاک 2014

In order to assess hydraulics of LNAPLs in soil, the soil retention curves of petroleum and water were both determined through hanging column method. And, the hydraulic conductivity of petroleum and water were determined by steady head method. The water and petroleum hydraulic conductivities were 7.27 and 57.84 cm.day-1, respectively. The soil retention parameters were obtained based on van Gen...

2013
Garey A. Fox Derek M. Heeren Glenn V. Wilson Eddy J. Langendoen Amanda K. Fox Maria L. Chu Maria L. Chu-Agor

Keywords: Groundwater seepage Pedotransfer function ROSETTA Seepage erosion Uncertainty analysis s u m m a r y Research has suggested that streambank seepage can be an important mechanism of bank instability; however, limited information is available on the level of soil characterization necessary to accurately predict seepage gradient forces and erosion. The objective of this research was to q...

2017
Matthew B. Thomas Payton Gardner Marco Maneta

Thomas, Matthew, B.S., May 2017 Geosciences Using Thermal Infrared Imaging to Estimate Soil Hydraulic Parameters: A Novel Approach Faculty Mentor: W. Payton Gardner, Marco Maneta In this study, skin temperature measured with a thermal infrared (TIR) camera was used to estimate soil hydraulic parameters. These physical properties that control how soils transport and retain water are notoriously ...

2012
Zilong Wang Qiuxiang Jiang Qiang Fu Tianxiao Li

The identification of freezing-thawing soil hydraulic properties is the basis and key problem of studying soil water movement. Current identifying methods of the properties have many limitations, such as big error, high uncertainty and low operability. Thus, the identifying method of freezingthawing soil hydraulic properties was researched in the research. The estimating parameters of soil free...

2002
Budiman Minasny

be described adequately by a soil hydraulic model that is a closed-form equation with a certain number of paramParametric pedotransfer functions (PTFs), which predict parameeters, e.g., Brooks and Corey or van Genuchten equation. ters of a model from basic soil properties are useful in deriving continuous functions of soil properties, such as water retention curves. The A parametric approach is...

2000
M. Inoue S. Shiozawa J. W. Hopmans

Estimation of soil hydraulic and solute transport parameters is important to provide input parameters for numerical models simulating transient water ̄ow and solute transport in the vadose zone. The Levenberg±Marquardt optimization algorithm in combination with the HYDRUS-1D numerical code was used to inversely estimate unsaturated soil-hydraulic and solute transport parameters from transient m...

ژورنال: علوم آب و خاک 2018

In this study, the values of moisture and soil temperature were estimated at different depths and times under unsteady conditions by solving the Richards’ equation in an explicit finite difference method provided in Visual Studio C#. For the estimation of soil hydraulic parameters, including av and nv (coefficients of van Genuchten’s equation) and Ks (saturated hydraulic conductivit...

2013
Marcel Bawindsom Kébré Fabien Cherblanc François Ouédraogo Jean-Claude Bénet François Zougmoré

The unsaturated soil hydraulic properties (the soil water characteristic and relative permeability curves) are key hydrodynamic parameters in the fields of soil science and civil engineering. Because of the strong dependency of these properties on water content, their determination is subject to considerable experimental and numerical problems. Difficulties increase when the soil approaches ove...

2009
Navin K. C. Twarakavi Jirka Šimůnek M. G. Schaap

[1] In the past, texture-based classification of soils has been used for grouping soils in variably saturated water flow and solute transport studies. Classification of soils becomes especially important for large-scale studies where the spatial and temporal variability in the hydraulic properties of soils exceeds the field sampling capabilities. Although soiltexture-based classification has be...

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