نتایج جستجو برای: effective hydraulic conductivity

تعداد نتایج: 754031  

2000
V. Comegna P. Damiani A. Sommella

With the aim of setting up a simpli®ed method to measure hydraulic conductivity of structured soils at saturation, a method reported by Ahuja et al. (Soil Sci. Soc. Amer. J. 48 (1984) 699±702; Soil Sci. 148 (1989) 404±411), which also refers to the generalised equation of Kozeny±Carman and the scaling theory, is tested in this paper. Data were elaborated from hydraulic conductivity measurements...

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...

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...

2008
Bradford Ramsay Joseph M. Sussman William Bradford Ramsay Patricia J. Culligan-Hensley John T. Germaine

The Wells G and H Superfund site, located in the Aberjona watershed in Woburn, Massachusetts, has been studied by a number of MIT research groups since 1987. Initial research conducted to characterize the hydraulic properties of the wetland deposits, did not indicate the classical trend linking changes in hydraulic conductivity to changes in total porosity. It was hypothesized, therefore, that ...

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...

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...

2011
Yiwei Cheng Marc Stieglitz Greg Turk Victor Engel

[1] Wetland ecosystems are often characterized by distinct vegetation patterns. Various mechanisms have been proposed to explain the formation of these patterns; including spatially variable peat accumulation and water ponding. Recently, short‐range facilitation and long‐range competition for resources (a.k.a scale dependent feedback) has been proposed as a possible mechanism for pattern format...

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...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید