نتایج جستجو برای: hydraulic conductivity function

تعداد نتایج: 1282700  

ژورنال: علوم آب و خاک 2013
بیژن نظری, , حامد ابراهیمیان, , محمود اکبری, , مسعود پارسی نژاد , ,

This study was conducted on subsurface drainage network under operation in Behshahr. DRAINMOD model was used to simulate drainage system using measured data in 2006. The model was evaluated to estimate soil hydraulic conductivity by comparing the measured and predicted values of water table depth and drain discharge for different values of hydraulic conductivity. The results of this method were...

2017
Yu-Pin Lin Yu-Wen Chen Liang-Cheng Chang Ming-Sheng Yeh Guo-Hao Huang Joy R. Petway

This study presents an approach for obtaining limited sets of realizations of hydraulic conductivity (K) of multiple aquifers using simulated annealing (SA) simulation and spatial correlations among aquifers to simulate realizations of hydraulic heads and quantify their uncertainty in the Pingtung Plain, Taiwan. The proposed approach used the SA algorithm to generate large sets of natural logar...

2011
S. Straface E. Rizzo F. Chidichimo

The characterization of a heterogeneous aquifer involves a wide spectrum of high resolution direct measurements of the characteristic parameters, defined in itinere according to the various approaches used. This information is usually obtained from the pumping tests and the relative measurements of the drawdown induced. Unfortunately, these methods are intrusive and the hydrological system is p...

2011
Thomas Wöhling Jasper A. Vrugt

[1] In the past two decades significant progress has been made toward the application of inverse modeling to estimate the water retention and hydraulic conductivity functions of the vadose zone at different spatial scales. Many of these contributions have focused on estimating only a few soil hydraulic parameters, without recourse to appropriately capturing and addressing spatial variability. T...

Journal: :Tree physiology 1992
M T Tyree J Alexander J L Machado

Despite many studies of the percent loss of hydraulic conductivity in excised branches, there is doubt as to whether cutting stems in air introduces unnatural embolism into the xylem at the cut surface. To address this question, hydraulic conductivity was measured in seedlings of northern red oak (Quercus rubra L.) and rooted scions of eastern cottonwood (Populus deltoides Bartr. ex Marsh.) tha...

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...

2003
T. Vogel H. H. Gerke R. Zhang M.Th. Van Genuchten

Most field soils exhibit soil spatial variability as well as soil structure. The challenge is to account adequately for both types of spatial heterogeneity in simulation models. A numerical finite element code was used to compare singleand dual-permeability approaches for modeling variably saturated flow and transport in two-dimensional heterogeneous soil systems. The code was based on the Rich...

Journal: :Tree physiology 2013
Xiang-Wen Fang Neil C Turner Dang-Hui Xu Yi Jin Jin He Feng-Min Li

Predawn leaf water potential (LWP), the LWP between 09:00 and 10:30 h (termed minimum LWP), stem xylem hydraulic conductivity, foliar nitrogen, leaf gas exchange and leaf traits were measured on the same days in adults and 1-year-old to 7-year-old resprouts that had regrown after removing all the aboveground shoots. Height growth and accumulation of aboveground biomass quickly decreased with re...

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: :Journal of environmental quality 2010
Rafael Muñoz-Carpena Garey A Fox George J Sabbagh

Vegetative filter strips (VFS) are an environmental management tool used to reduce sediment and pesticide transport from surface runoff. Numerical models of VFS such as the Vegetative Filter Strip Modeling System (VFSMOD-W) are capable of predicting runoff, sediment, and pesticide reduction and can be useful tools to understand the effectiveness of VFS and environmental conditions under which t...

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