نتایج جستجو برای: soil drainage 0028

تعداد نتایج: 219466  

2016
Dian-yuan Ding Ying Zhao Hao Feng Bing-cheng Si Robert Lee Hill

The primary objective of this study was to evaluate a range of calculation points on water retention curves (WRC) instead of the singularity point at air-entry suction in the pore-solid fractal (PSF) model, which additionally considered the hysteresis effect based on the PSF theory. The modified pore-solid fractal (M-PSF) model was tested using 26 soil samples from Yangling on the Loess Plateau...

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...

Journal: :تحقیقات آب و خاک ایران 0
حمیدرضا اولیائی ابراهیم ادهمی عبدالکریم اجرائی مهدی نجفی قیری مجید رجائی

soil drainage conditions significantly affect the chemical properties of soil, particularly type and the extent of iron oxides. soil magnetic susceptibility (?) has a close relationship with drainage conditions. eight soil profiles, in four regions of fars province, with aquic and non-aquic soil moisture regimes were studied to determine the effect of drainage conditions on ? and on chemical fo...

1998
Lowell E. Gentry Mark B. David Karen M. Smith David A. Kovacic

Ž . y Nitrogen N in surface waters has been linked to agricultural crop production, and more specifically, to NO exported 3 Ž by tile drainage. The objective of this study was to evaluate agricultural N pools and fluxes in a seed cornrsoybean Zea . Ž . y maize L.rGlycine max L. watershed 40 ha to relate soil inorganic N pools with annual losses of NO in drainage tiles. 3 During a 2-year period ...

Journal: :Radiotherapy and Oncology 2013

ژورنال: علوم آب و خاک 2008
نادری خوراسگانی, مهدی , کریمی, احمد ,

  This research was carried out to study the impacts of geomorphologic characteristics of claypan on land use and land degradation. Databank of the study area was constructed and digital terrain model of claypan was prepared. By using GIS techniques spatial distributions of the subsurface drainage network, sediment transportation index and wetness index were calculated. The results indicate tha...

2010
Xiaobing Lu Xuhui Zhang Shuyun Wang

Despite some studies on bearing capacity have been studied, the detail responses of the suction bucket foundations under dynamic loads have remained unknown [3]. The dynamic load condition is significant when suction buckets are used as the foundation of an offshore structure. Wave load, ice-induced or wind-induced load cause the foundation to be subjected to cyclic loads [4]. The dynamic load ...

Journal: :مدیریت آب و آبیاری 0
حسین مولوی دانشجوی کارشناسی ارشد گروه مهندسی آبیاری و آبادانی، دانشکده علوم آب و خاک، پردیس کشاورزی و منابع طبیعی، دانشگاه تهران مسعود پارسی نژاد دانشیار گروه مهندسی آبیاری و آبادانی، دانشکده علوم آب و خاک، پردیس کشاورزی و منابع طبیعی، دانشگاه تهران عبدالمجید لیاقت استاد گروه مهندسی آبیاری و آبادانی، دانشکده علوم آب و خاک، پردیس کشاورزی و منابع طبیعی، دانشگاه تهران

controlled drainage is one of the strategies to reduce negative environmental effects in conventional drainage systems. this study examines the effect of controlled drainage on quality and quantity of drainage water, specifically amounts of salt and nitrate in drainage water, and nitrate uptake by maize (sc 704) with sandy loam soil texture in karaj. the experiment was performed as a randomized...

Journal: :Journal of environmental quality 2014
Carolin Schweiker Anne Wagner Andre Peters Wolf-Anno Bischoff Martin Kaupenjohann

The leaching of trace metals from anthropogenically contaminated sites poses the risk of groundwater pollution. Biochar has recently been proposed as a soil additive to reduce trace-metal concentrations in the soil solution and to increase water retention, thus reducing drainage. However, field studies on the effects of biochar addition on trace-metal leaching are scarce. Therefore, we added 0,...

2012

Subsurface drainage involves both intensity and capacity attributes. Intensity of subsurface drainage refers to how rapidly a root zone drains. Capacity, on the other hand, refers to the extent of excess (gravitational) water removal from the root zone. Consequently, discussions of putting green drainage often become confused since the expression improved drainage can imply improved drainage ca...

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