نتایج جستجو برای: hydraulic conductivity

تعداد نتایج: 75578  

Journal: :Ground water 2015
Jianying Jiao Ye Zhang

A physically based inverse method is developed using hybrid formulation and coordinate transform to simultaneously estimate hydraulic conductivity tensors, steady-state flow field, and boundary conditions for a confined aquifer under ambient flow or pumping condition. Unlike existing indirect inversion techniques, the physically based method does not require forward simulations to assess model-...

Journal: :journal of agricultural science and technology 2010
a. keyhani d. wulfsohn

a pressure-based coupled heat and mass transfer model was used to simulate temperature and soil suction in a drying process within a clay soil column. closed form functions were used for all parameters needed in the governing equations. model predictions were compared with experimental data using the mean relative percentage deviation method. thermocouples and mini-gypsum blocks were used t...

Journal: :آب و خاک 0
رضا لاله زاری سعید برومند نسب هادی معاضد علی حقیقی

introduction: groundwater is the largest resource of water supplement and shortages of surface water supplies in drought conditions that requires an increase in groundwater discharge. groundwater flow dependson the subsurface properties such as hydraulic gradient (water table gradient or head loss in artesian condition) and hydrodynamic coefficients. the flow treatment is analyzed with an accur...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2015
Robert Paul Skelton Adam G West Todd E Dawson

Attempts to understand mechanisms underlying plant mortality during drought have led to the emergence of a hydraulic framework describing distinct hydraulic strategies among coexisting species. This framework distinguishes species that rapidly decrease stomatal conductance (gs), thereby maintaining high water potential (Px; isohydric), from those species that maintain relatively high gs at low ...

Journal: :Water research 2006
C D Beal E A Gardner G Kirchhof N W Menzies

Soil absorption systems (SAS) are used commonly to treat and disperse septic tank effluent (STE). SAS can hydraulically fail as a result of the low permeable biomat zone that develops on the infiltrative surface. The objectives of this experiment were to compare the hydraulic properties of biomats grown in soils of different textures, to investigate the long-term acceptance rates (LTAR) from pr...

Journal: :تحقیقات آب و خاک ایران 0
مهسا جمشیدی دانشجوی کارشناسی ارشد دانشگاه بین المللی امام خمینی (ره) پیمان دانش کار آراسته استادیار دانشگاه بین المللی امام خمینی) ره) عباس ستوده نیا استادیار دانشگاه بین المللی امام خمینی) ره)

application of outflow water from treatment plants for irrigation as a non-usual water resource is being developed due to the lack of usual water resources in iran. activated carbon as a conditioner in water treatment procedures causes undesired changes in hydraulic properties of porous media and soil degradation. in this paper, the effects of activated carbon concentration on hydrodynamic prop...

Journal: :Tree physiology 2011
Da-Yong Fan Sheng-Lin Jie Chang-Cheng Liu Xiang-Ying Zhang Xin-Wu Xu Shou-Ren Zhang Zong-Qiang Xie

Karst topography is a special landscape shaped by the dissolution of one or more layers of soluble bedrock, usually carbonate rock such as limestone or dolomite. Due to subterranean drainage, overland flow, extraction of water by plants and evapotranspiration, there may be very limited surface water. The hydraulic architecture that plants use to adapt to karst topography is very interesting, bu...

2016
Usman Anwar Randall K. Kolka John Tyndall Randall Kolka

Predicting the hydrologic consequences of biomass cropping systems requires an understanding of how different crops and management practices affect soil hydraulic properties across space and time. To inform such predictions, I investigated the impacts of five biomass cropping systems on the hydraulic properties of soils across a landscape gradient in wet, dry, and average rainfall years. I used...

Journal: :American journal of botany 2011
Katherine A McCulloh Daniel M Johnson Frederick C Meinzer Barbara Lachenbruch

PREMISE OF THE STUDY The Pacific Northwest of North America experiences relatively mild winters and dry summers. For the tall coniferous trees that grow in this region, we predicted that loss in the hydraulic conductivity of uppermost branches would be avoided because of difficulty reversing accumulated emboli in xylem that is always under negative pressure. METHODS To test this hypothesis, w...

2005
Marcel G. Schaap

The unsaturated soil hydraulic properties are often described using Mualem–van Genuchten (MVG) type analytical functions. Recent studies suggest several shortcomings of these functions near saturation, notably the lack of second-order continuity of the soil water retention function at saturation and the inability of the hydraulic conductivity function to account for macroporosity. We present a ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید