نتایج جستجو برای: hydraulic conductivity function

تعداد نتایج: 1282700  

Journal: :تحقیقات آب و خاک ایران 0
کامی کابوسی عبدالمجید لیاقت حسن رحیمی

regarding the role and importance of subsurface drainage in water table control, many studies have been made throughout the world to find out new techniques and more economical solutions, especially as related to different pipe envelope material and their installations. this research was conducted to investigate the use of rice husk, as drain envelope material, in drainage installations. in add...

2013
Jianye Wang Kaixuan Zhu Gang Zhao Jian Ren Cui Yue Dayong Gao

The Sf21 cell line is extensively used for virus research and producing heterologous recombinant proteins. To develop optimal strategies for minimizing cell injury due to intracellular ice formation and excessive volume shrinkage during cryopreservation, the fundamental transport properties including the osmotic inactive volume (Vb ), the hydraulic conductivity (Lp ), and the glycerol permeabil...

1999
Anthony T. Cahill Fabrizio Ungaro Marc B. Parlange Michael Mata Donald R. Nielsen

A method for determining optimal parameters for a field-scale hydraulic conductivity function is presented and tested on soil moisture and matric potential data measured at several locations in a field drainage experiment. The change in moisture content over time at the individual locations is modeled using Richards’ equation, and an optimization for the hydraulic conductivity parameters is per...

2010
Andrew S. Gregory Nigel R.A. Bird W. Richard Whalley Peter Matthews

To understand the hydraulic properties of soils, accurate prediction of unsaturated hydraulic conductivity is needed which is commonly derived from the soil water release characteristic. In fine-textured soils the modified Mualem-van Genuchten (MMVG) function has been used extensively to predict the change in relative conductivity with changes in matric potential, but this assumes that the soil...

Journal: :Tree physiology 2017
José M Olano Noelia González-Muñoz Alberto Arzac Vicente Rozas Georg von Arx Sylvain Delzon Ana I García-Cervigón

Increased drought frequency and severity may reshape tree species distribution in arid environments. Dioecious tree species may be more sensitive to climate warming if sex-related vulnerability to drought occurs, since lower performance of one sex may drive differential stress tolerance, sex-related mortality rates and biased sex ratios. We explored the effect of sex and environment on branch h...

2014
Evan Earnest David Boutt

Fractured-rock aquifers display spatially and temporally variable hydraulic conductivity generally attributed to variable fracture intensity and connectivity. Empirical evidence suggests fracture aperture and hydraulic conductivity are sensitive to in situ stress. This study investigates the sensitivity of fractured-rock hydraulic conductivity, groundwater flow paths, and advectiondominated tra...

2007
J. Eggleston

Hydraulic conductivity is commonly estimated from grain size characteristics of unconsolidated sediments. We present an extensive set of air-permeability and grain size measurements from a heterogeneous aquifer. These data are unique in that the hydraulic conductivity measurements are made on undisturbed in-situ sediment and, like the grain size measurements, have a small sample volume size (<1...

2003
Kai Schwaerzel Heiko P. Bohl

A simple method for the installation of groundwater lysimeters in peat soils was developed which reduces both time and financial effort significantly. The method was applied on several sites in the Rhinluch, a fen peat land 60 km northwest of Berlin, Germany. Over a two-year period, upward capillary flow and evapotranspiration rates under grassland with different groundwater levels were measure...

Saturated hydraulic conductivity of soil is an important physical property of soil that affects water movement in soil, Since the measurement of saturated hydraulic conductivity by direct methods in the field or in the laboratory is hard, time-consuming and costly, the indirect methods are being used.The aim of this study is to estimate the saturated hydraulic conductivity from other soil prope...

1999
Alex S. Mayer Changlin Huang

The coupled ̄ow-mass transport inverse problem is formulated using the maximum likelihood estimation concept. An evolutionary computational algorithm, the genetic algorithm, is applied to search for a global or near-global solution. The resulting inverse model allows for ̄ow and transport parameter estimation, based on inversion of spatial and temporal distributions of head and concentration meas...

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