نتایج جستجو برای: Saturated hydraulic conductivity

تعداد نتایج: 107910  

2013
A. I. Ekhmaj A. M. Abdulaziz

The saturated hydraulic conductivity of soil is needed for deteriming the agricultural and hydrological processes. The measurement techniques used to estimate such property remain hampered by extensive labor and time constraints. Both emitter discharge rate and steady saturated radius emerged from point source trickle irrigation on the soil surface were used to determine the saturated hydraulic...

Journal: :تحقیقات مهندسی کشاورزی 0
بهزاد قنبریان علویجه دانشجوی دکتری دانشکده آب و خاک پردیس کشاورزی و منابع طبیعی دانشگاه تهران عبدالمجید لیاقت دانشیار گروه آبیاری و آبادانی دانشکده آب و خاک پردیس کشاورزی و منابع طبیعی دانشگاه تهران سمانه سهرابی دانشجوی کارشناسی ارشد گروه مهندسی آب دانشکده کشاورزی دانشگاه تبریز

soil hydraulic properties such as saturated and unsaturated hydraulic conductivity play an important role in environmental research. since direct measurement of these soil hydraulic properties is time-consuming and costly, indirect methods such as pedotransfer functions and artificial neural networks (ann) were developed based on readily available parameters. in this study, the use of ann to pr...

ژورنال: علوم آب و خاک 2017

Treated wastewater may influence soil structure, porosity and as a consequence, soil saturated hydraulic conductivity. This study aims to assess the effect of wastewater on saturated hydraulic conductivity; and to determine the suitable soil solids fractal dimension to incorporate into the pedotransfer function by Rawls et al (1993) for estimation of saturated hydraulic conductivity (Ks). Soi...

Journal: :iran agricultural research 2012
b. ghahraman s. omidi a. khoshnood yazdi

measurement of soil saturated hydraulic conductivity, ks, is normally affected by flow patterns such as macro pore; however, most current techniques do  not differentiate flow types, causing major problems in describing water and chemical flows within the soil matrix. this study compares eight models for scaling ks and predicted matrix and macro pore ks, using a database composed of 50 datasets...

Journal: :desert 2008
h. motaghian j. mohammadi a. karimi

soil hydrau-physical data are important for many hydrological modelings. they are the main variables controllingthe key processes such as water and chemicals movement and transport in the soil profiles. this study was conductedin order to analyze the spatial distribution of selected soil hydrau-physcial characteristics including infiltration rate(ir), saturated hydraulic conductivity (ks), bulk...

Journal: :آب و خاک 0
عقیل یاری عبداله درزی مجتبی شقاقی روح اله یاری

abstract the temperature of water entering the soil or variation in soil temperature has a direct impact on soil hydraulic conductivity via the effect on water viscosity. in this research, the time variability of soil saturated hydraulic conductivity (ks) was studied. the relation between soil temperature and fluid viscosity with hydraulic conductivity were also studied. the necessary experimen...

Journal: :آب و خاک 0
فاطمه مسکینی ویشکائی محمود شعبانپور شهرستانی ناصر دوات گر

abstract the saturated hydraulic conductivity (ks) is an important physical property of soil. the direct measurement of this property in soils is a difficult and time consuming process. pedotransfer functions (ptfs) provide an alternative by estimating soil parameters from more readily available soil data. the objective of this study is to determine effective factors on soil hydraulic conductiv...

Journal: :کشاورزی (منتشر نمی شود) 0
بهروز مصطفی زاده استادیار، دانشکده کشاورزی دانشگاه صنعتی اصفهان سید فرهاد موسوی دانشیار، دانشکده کشاورزی دانشگاه صنعتی اصفهان

to design subsurface drainage systems, it is necessary to determine the saturated hydraulic conductivity of the soil. one of the most common methods for field measurement of this parameter is the shallow well pump-in test method. another method which has recently been introduced for the above measurement is the guelph permeameter method. both methods are used to measure the soil saturated hydra...

Journal: :آب و خاک 0
وحیدرضا جلالی مهدی همایی

abstract saturated hydraulic conductivity (ks) is needed for many studies related to water and solute transport, but often cannot be measured because of practical and/or cost-related reasons. nonparametric approaches are being used in various fields to estimate continuous variables. one type of the nonparametric lazy learning algorithms, a k-nearest neighbor (k-nn) algorithm, was introduced and...

2013
Paolo Nasta Jasper A. Vrugt Nunzio Romano

[1] Prediction of flow through variably saturated porous media requires accurate knowledge of the soil hydraulic properties, namely the water retention function (WRF) and the hydraulic conductivity function (HCF). Unfortunately, direct measurement of the HCF is time consuming and expensive. In this study, we derive a simple closed-form equation that predicts the saturated hydraulic conductivity...

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