نتایج جستجو برای: soil unsaturated hydraulic conductivity

تعداد نتایج: 265684  

Journal: : 2023

A simple technique is proposed in this paper for estimating the coefficient of permeability an unsaturated soil based on physical properties soils that include grain size analysis, degree saturation or water content, and porosity soil. The method requires soil-water characteristic curve prediction as most conventional methods. procedure to define hydraulic conductivity function from which measu...

2007
Stewart Wuest

The assumption that seeds imbibe most of the water required for germination as liquid through seed-to-soil contact has been a dominant theme in germination research and seeding technology. Under most conditions, seeds are also exposed to water vapour during imbibition, but the relative contributions of liquid and vapour are difficult to assess. In water uptake models that include vapour, proced...

2000
T. Vogel

Relatively small changes in the shape of the soil water retention curve near saturation can signi®cantly a€ect the results of numerical simulations of variably saturated ̄ow, including the performance of the numerical scheme itself in terms of stability and rate of convergence. In this paper, we use a modi®ed form of the van Genuchten±Mualem (VGM) soil hydraulic functions to account for a very ...

2015
A. Farid Elisa H. Barney Smith

Hydraulic conductivity is a measure of the rate at which water flows through porous media. Because of the dipole properties of water molecules, any electric field can affect hydraulic conductivity. In this study, the effect of radio-frequency (RF) waves on hydraulic conductivity is investigated. This is important both for the geophysical measurement of hydraulic conductivity as well as remediat...

2015
Atena Najafi Sahba Azad Arvin Farid Jim Browning Elisa Barney Smith

Hydraulic conductivity is a measure of the rate at which water flows through porous media. Because of the dipole properties of water molecules, electric field can affect hydraulic conductivity. In this study, the effect of radio-frequency (RF) waves on hydraulic conductivity is investigated. This is important both for the geophysical measurement of hydraulic conductivity as well as remediation ...

2009
C. M. Rubio R. Josa R. Poyatos P. Llorens F. Gallart J. Latron F. Ferrer

The main goal of this work is to determine and to evaluate the saturated hydraulic conductivity for a silt loam soil in field and laboratory conditions. The experimental area was located in the Vallcebre research catchments, in headwaters of the Llobregat River (NE Spain). Hydraulic conductivity was measured in the field using the Guelph permeameter and field saturated hydraulic conductivity (K...

2010
Robert A. Brown

Bioretention cells are incorporated as part of low impact development LID because of their ability to release influent runoff as exfiltration to the soil or evapotranspiration to the atmosphere. However, little care is taken as to the techniques used to excavate bioretention cells, and there is little concern as to the soil-moisture condition during excavation. Certain excavation techniques and...

ژورنال: علوم آب و خاک 2014
امیری, وهاب, نخعی, محمد,

Modeling of flow and transport processes in variably saturated porous media requires detailed knowledge of the soil hydraulic properties. The hydraulic properties to be determined by the inverse problem solution are the unsaturated hydraulic conductivity K(h) and the water retention curve θ(h). The inverse modeling approach assumes that both θ(h) and K(h) as well as transport parame...

Journal: :Journal of experimental botany 2001
J Nijsse G W van der Heijden W van Ieperen C J Keijzer U van Meeteren

The stem xylem conduit dimensions and hydraulic conductivity of chrysanthemum plants (Dendranthema x grandiflorum Tzvelev cv. Cassa) were analysed and quantified. Simple exponential relations describe conduit length distribution, height dependency of conduit length distribution, and height dependency of stem hydraulic conductivity. These mathematical descriptions can be used to model the xylem ...

1999
M. L. Serre G. Christakos

Classical Geostatistics methods have been designed to use mainly statistical knowledge about natural variables and they lack the ability to incorporate important forms of knowledge like physical laws and scientific theories into the mapping process. On the other hand, the powerful and versatile Bayesian maximum entropy (BME) method of Modern Geostatistics can accomplish such a task, rigorously ...

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