نتایج جستجو برای: saturated hydraulic conductivity

تعداد نتایج: 107910  

2010
Valentijn R. N. Pauwels Peter A. Troch

[1] The estimation of catchment-averaged aquifer hydraulic conductivity values is usually performed through a base flow recession analysis. Relationships between the first time derivatives of the base flow and the base flow values themselves, derived for small and large values of time, are used for this purpose. However, in the derivation of the short-time equations, an initially fully saturate...

2005
C. Fallico

Papers published in Hydrology and Earth System Sciences Discussions are under open-access review for the journal Hydrology and Earth System Sciences Abstract In the context of studies aiming at the estimation of effective parameters for unsaturated zone modelling, this work tackles the problem of experimental data quality, considering the large collection of data gathered at an experimental sit...

ژورنال: علوم آب و خاک 2012
روح اله رضایی ارشد, , علیرضا جعفرنژادی, , غلامعباس صیاد, , مسعود مظلوم, , مهدی شرفا, ,

Direct measurement of soil hydraulic characteristics is costly and time-consuming. Also, the method is partly unreliable due to soil heterogeneity and laboratory errors. Instead, soil hydraulic characteristics can be predicted using readily available data such as soil texture and bulk density using pedotransfer functions (PTFs). Artificial neural networks (ANNs) and statistical regression are t...

2004
Jozsef Szilagyi

Aquifer drainage was numerically simulated by a coupled, unsaturated-saturated flow equation. The effect of the vadose zone on aquifer parameter predictions of classical hydraulic theory was investigated. Saturated-zone hydraulic theory was shown to be fairly robust in estimating the saturated hydraulic conductivity but less so in estimating drainable porosity, mainly because of the much tighte...

Journal: :تحقیقات آب و خاک ایران 0
حجت احمدی استادیار گروه آب دانشگاه ارومیه حسین رضایی دانشیار گروه آب دانشگاه ارومیه کامران زینالزاده استادیار گروه آب دانشگاه ارومیه

seepage analysis through earth dams is employed to determine the water loss. moreover, as the magnitude of pore pressure in dam body is calculated using seepage analysis, this analysis plays an important role on the stability analysis in these types of structures. as the hydraulic conductivity of the earth dam materials, is considered as one of the effective parameters on the magnitude of seepa...

2013
Paolo Nasta Nunzio Romano Shmuel Assouline Jasper A. Vrugt Jan W. Hopmans

[1] Simultaneous scaling of soil water retention and hydraulic conductivity functions provides an effective means to characterize the heterogeneity and spatial variability of soil hydraulic properties in a given study area. The statistical significance of this approach largely depends on the number of soil samples collected. Unfortunately, direct measurement of the soil hydraulic functions is t...

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...

Journal: :آب و خاک 0
متقیان متقیان محمّدی محمّدی

abstract the effect of land use type on soil functioning within an ecosystem can be assessed and monitored using soil quality attributes. such studies, which are carried out to create a balance between the biological production and the maintenance and improvement of land resource quality, provide a framework for land degradation control and also for identification of sustainable management. in ...

2008
M. Berli A. Carminati T. A. Ghezzehei

[1] Prediction of water flow and transport processes in soils susceptible to structural alteration such as compaction of tilled agricultural lands or newly constructed landfills rely on accurate description of changes in soil unsaturated hydraulic conductivity. Recent studies have documented the critical impact of aggregate contact characteristics on water flow rates and pathways in unsaturated...

R. Sedghi S. Bairami Y. Hoseini

ABSTRACT-Determining hydraulic conductivity of soil is difficult, expensive, and time-consuming. In this study, Algorithm Genetic and geostatistical analysis and Neural Networks method are used to estimate soil saturated hydraulic conductivity using the properties of particle size distribution. The data were gathered from 134soil profiles from soil and lander form studies of the Ardabil Agricul...

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