نتایج جستجو برای: soil parameter

تعداد نتایج: 392761  

2015
Brecht Martens Hans Lievens Andreas Colliander

Despite the continuing efforts to improve existing soil moisture retrieval algorithms, the ability to estimate soil moisture from passive microwave observations is still hampered by problems in accurately modelling the observed microwave signal. Due to the significant influence of both soil roughness and vegetation on the measured brightness temperatures, the parameterisation of these variables...

Journal: :تحقیقات آب و خاک ایران 0
پریسا مشایخی دانشجوی دکتری/دانشگاه شهرکرد شجاع قربانی دشتکی هیئت علمی محمدرضا مصدقی هیات علمی/دانشگاه صنعتی اصفهان حسین شیرانی هیات علمی/دانشگاه حضرت ولی عصر رفسنجان مهدی پناهی هیات علمی/موسسه تحقیقات خاک و آب کرج محمدرضا نوری هیات علمی/دانشگاه شهرکرد

in this study, hydrus2d/3d software was used to estimate the hydraulic parameters of van genuchten-mualem model via inverse modeling using double-ring infiltrometers data in 3 different soil textures. nine scenarios of inverse modeling (divided in three groups) were considered with different number (5, 4 and 3) of fitted hydraulic parameters for optimization. in the first group, simulation was ...

ژورنال: علوم آب و خاک 2014
حسام آریان‌پور, , مهدی شرفا, ,

Soil tillage changes chemical and physical properties which can change the soil available water capacity. For understanding the effect of soil disturbance in cultivated soil on available water, parameter pedotransfer functions of these soils created and their results were compared with measured available water by moisture release curves. For this purpose 54 soil samples were taken from cultiva...

2009
V. K. Gupta Raj Rishi

Dielectric constant values of the samples of soil of Alwar (at various moist states) have been calculated using wave guide cell method at a single microwave frequency 9.78 GHz at 33C. The Backscattering coefficients for rough and bare soil surfaces 0 soil σ are calculated by Small Perturbation Model (SPM). Fresnal reflectivity of the soil surfaces which is an input parameter for SPM is calculat...

2002
C. W. Rose

*C.W. Rose, Faculty of Environmental Sciences, Griffith University, Queensland 4111, Australia. *Corresponding author: [email protected] ABSTRACT A catena of modeling approaches are briefly reviewed including dynamic stochastic and deterministic approaches. It is shown that a dynamic stochastic description of soil erosion, with appropriate parameter identification, can be identified with...

ژورنال: علوم آب و خاک 2018

In this study, the values of moisture and soil temperature were estimated at different depths and times under unsteady conditions by solving the Richards’ equation in an explicit finite difference method provided in Visual Studio C#. For the estimation of soil hydraulic parameters, including av and nv (coefficients of van Genuchten’s equation) and Ks (saturated hydraulic conductivit...

2008
C. Albergel C. Rüdiger T. Pellarin J.-C. Calvet N. Fritz F. Froissard

A long term data acquisition effort of profile soil moisture is under way in southwestern France at 13 automated weather stations. This ground network was developed in order to validate remote sensing and model soil moisture estimates. In this paper, both those in situ observations and a synthetic data set covering continental France are used to test a simple method to retrieve root zone soil m...

ژورنال: علوم آب و خاک 2014
اسلامیان, سید سعید, عابدی کوپایی, جهانگیر , ملکیان, راحله ,

In this study, the effect of clinoptilolite zeolite, as a soil amendment, on the parameters related to water and nitrogen movement in soil was investigated. Parameter and uncertainty estimation in the unamended (control) and amended soil (Z), was performed using the sequential uncertainty fitting algorithm (SUFI-2) which is linked to LEACHN (in the LEACHN-CUP software). The goodness of predic...

Journal: :Environmental Modelling and Software 2015
Magdalena Necpálová Robert P. Anex Michael N. Fienen Stephen J. Del Grosso Michael J. Castellano John E. Sawyer Javed Iqbal José L. Pantoja Daniel W. Barker

The ability of biogeochemical ecosystem models to represent agro-ecosystems depends on their correct integration with field observations. We report simultaneous calibration of 67 DayCent model parameters using multiple observation types through inverse modeling using the PEST parameter estimation software. Parameter estimation reduced the total sum of weighted squared residuals by 56% and impro...

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