نتایج جستجو برای: irrigation channel embankment and hydraulic conductivity coefficient

تعداد نتایج: 16898008  

H Es-haghi Sharabiani M Gharavi

Hydraulic conductivity variations around the boreholes in uniformly graded sands for cyclic water injection pressure have been evaluated by laboratory tests. Prototype laboratory devices have been designed and constructed for this research. The cell has a capability to model the well, the boundary condition and to measure the hydraulic conductivity. While increasing water injection pressure, hy...

Journal: :آب و خاک 0
رسول قبادیان کامران محمدی

abstract information on spatial and temporal variations of soil hydraulic conductivity (k) is essential to improve soil and water management. however several techniques have been proposed for measuring of soil hydraulic conductivity above water surface table, but reliability and easy use of these methods in various conditions were always concern for engineers. the purposes of this study are mea...

Journal: :Journal of contaminant hydrology 2005
Xianda Zhao Roger B Wallace David W Hyndman Michael J Dybas Thomas C Voice

Hydraulic conductivity and sorption coefficients for chlorinated hydrocarbons (chloroform, carbon tetrachloride and tetrachloroethylene) were evaluated for 216 sediment samples collected across a 15 m transect and a 21 m depth interval in a contaminated aquifer near Schoolcraft, Michigan. Relationships between hydraulic conductivity, linear sorption partition coefficients, grain size classes, a...

An increase in the flow velocity in flowthrough large porous media and deflection of flow regime from Darcy law causes a nonlinear relationship between hydraulic gradient and pore velocity of media. So many investigations have done previously in such Medias. One of the most important subjects in flowthrough large porous media is relationship between friction coefficient and flow characteristics...

2010
Pierre-Olivier MALATERRE David C. ROGERS

Irrigation is well known for being the largest water user, responsible for about 70% of the total amount of fresh water withdrawals. At the same time, this irrigation contributes for about 40% of the total food production and is vital for many regions of the world such as Western USA, Australia, Southern Europe, and many countries in Asia and Africa. Recent FAO figures indicate that, by the yea...

2001
Jan W. Hopmans

In order to better manage and monitor fluid flow and migration of chemicals in gas and liquid phases, a fundamental understanding and knowledge of the saturation dependency of permeability, diffusion and electrical conductivity in a porous medium is required. The initial fundamental formulations and recent research for characterization of transport properties in porous media are discussed. To i...

Journal: :The Journal of General Physiology 1971
C. M. Gary-Bobo A. K. Solomon

Studies have been made on the temperature dependence of both the hydraulic conductivity, L(p), and the THO diffusion coefficient, omega, for a series of cellulose acetate membranes (CA) of varying porosity. A similar study was also made of a much less polar cellulose triacetate membrane (CTA). The apparent activation energies, E(a), for diffusion across CA membranes vary with porosity, being 7....

2005
Hubert Chanson

Forensic studies of past hydraulic structure failures are rare despite their critical relevance to modern hydraulic design, and the writers (Dai et al., 2005) must be congratulated for their outstanding study. Herein the discussion is focused on two aspects of the conclusion. It is believed that dam overtopping was the primary cause of the Dadu river landslide dam failure, although aftershocks ...

ژورنال: علوم آب و خاک 2012
بیژن خلیل‌مقدم, , جهانگرد محمدی, , حبیب خداوردی‌لو, , سیروس دهقانی بانیانی, , شجاع قربانی دشتکی, ,

Saturated hydraulic conductivity (Kfs) and macroscopic capillary length of soil pores are important hydraulic properties for water flow and solute transport modeling. Measuring these parameters is tedious, time consuming and expensive. One way is using indirect methods such as Pedotransfer functions (PTFs). The objective of this research was to develop some PTFs for estimating saturated hydraul...

محمدرضا نیشابوری, , حسین رضائی, , علیرضا سپاسخواه, ,

Hydraulic coefficients of a porous media such as hydraulic conductivity K(θ) and diffusivity D(θ) have a controlling role in the evaluation of groundwater flow and pollutant transport behavior. Therefore, successful porous media flow evaluation depends on the accurate determination of its hydraulic coefficients. But it is hard and time consuming to measure. Values for these coefficients accurat...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید