نتایج جستجو برای: soil unsaturated hydraulic conductivity

تعداد نتایج: 265684  

2014
J. HEPPELL

Management and irrigation of plants increasingly relies on accurate mathematical models for the movement of water within unsaturated soils. Current models often use values for water content and soil parameters that are averaged over the soil profile. However, many applications require models to more accurately represent the soil–plant–atmosphere continuum, in particular, water movement and satu...

2003
Guo-Yue Niu Zong-Liang Yang

Three different schemes of topography-based runoff production [versatile integrator of surface atmospheric processes (VISA)-TOP1, VISA-TOP2, and VISA-TOP3] are described for a land-surface model (LSM) developed for use with a general circulation model (GCM). The schemes’ sensitivities to some key parameters are assessed for two catchments using data sets developed for the Project for Intercompa...

2014
Jonathan Istok

approved: ______________________________________________________ Jonathan Istok Estimating the hydraulic conductivity of earth materials is important for many water resource modeling efforts, including predicting the transport of pollutants in ground water, computing surface runoff for flood control, and computing water budgets. This research implicitly used topography, soil, and climate data t...

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: :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...

A. R. Sepaskhah M. Fooladi Dorhani

ABSTRACT-Application of models for simulation of solute and pollutants transport in soil can reduce time and costs for remediation process. HYDRUS-1D model was developed to simulate the one–dimensional flow of soil water, heat, solute and viruses in variably saturated–unsaturated porous media. The objective of this investigation is to determine the solute transport parameters in disturbed soil ...

2004
Dale F. Rucker

ity and the van Genuchten . In this study, we apply this approach to measurements of wetting front advance Inverse methods to obtain soil hydraulic parameters are becoming made under simulated field conditions. increasingly popular, due to their more rapid, complete, and robust estimations of hydraulic parameters compared with traditional direct Standard methods typically determine the hydrauli...

ژورنال: علوم آب و خاک 2014
امیری, الهام , شیرانی, حسین , محبوبی, علی اکبر , مصدقی, محمد رضا ,

In this study, the effect of soil structure under saturated and unsaturated flow conditions on nonreactive bromide (BR) transport was investigated. The soil structure treatments consisted of undisturbed columns (prismatic and granular structures), and disturbed columns (single- grain structure). A constant concentration (C0= 0.005 M) of bromide was supplied on the surface of the columns in a st...

2004
Masaki Hayashi William L. Quinton

Hayashi, M. and Quinton, W. L. 2004. A constant-head well permeameter method for measuring field-saturated hydraulic conductivity above an impermeable layer. Can. J. Soil Sci. 84: 255–264. Hydrologic understanding of mountainous and northern regions of Canada is poor owing to the lack of critical field data such as hydraulic conductivity. A portable field instrument, the Guelph permeameter (GP)...

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