نتایج جستجو برای: hydraulic conductivity function

تعداد نتایج: 1282700  

2005
Scott Purdy

Accurately measuring the in situ hydraulic conductivity (permeability) of a clay liner is a major factor in the construction of landfill containment systems. Laboratory and large-scale field test methods are often utilized on test pads constructed prior to placement of the production liner to determine the hydraulic conductivity of the clay. While these test methods provide reliable results, th...

2007
Zhiming Lu Dongxiao Zhang Bruce A. Robinson

[1] In this study, we directly derive first-order analytical solutions to the pressure head moments (mean and variance) for one-dimensional steady state unsaturated flow in randomly heterogeneous layered soil columns under various random boundary conditions. We assume that the constitutive relation between the unsaturated hydraulic conductivity and the pressure head follows an exponential model...

2005
M. M. VILLAGRA P. MICHIELS R. HARTMANN

Experimentally determined values of unsaturated soil hydraulic conductivity are presented for an Alfisol of the county of Piracicaba, S.P., Brazil. Simultaneous measurements of soil water content and pressure head are made along a 125 m transect within an irrigated field during the internal drainage process. Calculations of the soil hydraulic conductivity were made using the instantaneous profi...

Journal: :Computers & Geosciences 2010
Haiyan Zhou Liangping Li J. Jaime Gómez-Hernández

The main point of this paper is to propose a non-local three-dimensional hydraulic conductivity full tensor upscaling algorithm and code. The algorithm is capable of transforming very refined cell conductivity models into coarse block conductivity models for quick and accurate solution of the groundwater flow equation. Flow rate and hydraulic head gradient are the variables used to relate the o...

Abbas Maleki Ali Mokhtaran Mohammad Salakhpoor,

In studies of irrigation and drainage projects for drainage, it is necessary to extend the data from the sampling point to the network. Therefore, based on available data from observational wells, estimating the state of hydraulic conductivity (K) in the surrounding area. The estimation process values for locations where there is no information for them based on viewing areas called wells spati...

Journal: :The New phytologist 2013
Stefano Manzoni Giulia Vico Gabriel Katul Sari Palmroth Robert B Jackson Amilcare Porporato

Soil and plant hydraulics constrain ecosystem productivity by setting physical limits to water transport and hence carbon uptake by leaves. While more negative xylem water potentials provide a larger driving force for water transport, they also cause cavitation that limits hydraulic conductivity. An optimum balance between driving force and cavitation occurs at intermediate water potentials, th...

Elahe Pormand Sepideh Bagheri Shayan Shariati,

Sodic soil is one of the most common problems of limiting agricultural production that related on irrigation. Saturated hydraulic conductivity is one of hydrodynamic characteristics in evaluating transmission flow through underground levels. To investigate the role of increment of exchangeable sodium in hydraulic conductivity changes (as characterized by the mobility of water in soil) an experi...

2016
Uwe Schindler Lothar Müller Chalermchai Wongs-Aree Sirichai Kanlayanarat Douglas D. Archbold

Abstract: Horticultural substrates, also referred to as growing media, potting soils and gardening or soilless substrates, are widely used as a basis for vegetable and flower production in horticulture. They are created as a composition of different ingredients (bog peat, organic residuals, coir, perlite and other components). Hydraulic properties such as water storage capacity, air capacity, s...

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