نتایج جستجو برای: source of irrigation water

تعداد نتایج: 21241901  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده علوم انسانی 1389

rivers and runoff have always been of interest to human beings. in order to make use of the proper water resources, human societies, industrial and agricultural centers, etc. have usually been established near rivers. as the time goes on, these societies developed, and therefore water resources were extracted more and more. consequently, conditions of water quality of the rivers experienced rap...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان 1390

during natural gas processing, water in natural gas may cause to hydrates formation in pipelines which may lead to serious damages to process equipments. given the problems raised by present of water in natural gas, glycol solvent uses to remove water.in contact of glycol with gas always an amount of btex and voc absorb along with water, which on glycol recovery process, these substances separa...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت معلم تهران - دانشکده علوم 1370

determination of uranium in natural water and complex solutions using ion exchange chromatography: a combined procedure using ion exchange chromatography and uv-vis spectrophotometry techniques has been developed to measure uranum in natural water and complex solutions. after conditicing , one hundred milli liters of sample solutions have been passed through an ion exchange column,pachked with ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی 1392

flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...

Journal: :پژوهش آب در کشاورزی 0
کوروش مجد سلیمی محقق بخش تحقیقات فنی و مهندسی مرکز تحقیقات چای کشور. ابراهیم امیری دانشیار گروه کشاورزی، دانشگاه آزاد اسلامی واحد لاهیجان. سید بابک صلواتیان محقق بخش تحقیقات فنی و مهندسی مرکز تحقیقات چای کشور.

sustainable economical production of tea depends on the proper use of water and fertilizer. for this purpose, the role of supplemental irrigation and nitrogen fertilizer on economical production of tea plantations was studied by assessment of yield, production function, water use efficiency, and benefit/cost ratio, and final return in a field experiment at feshalam tea research station in fouma...

2016
C. S. Kim Todd Guilfoos

Empirical studies suggest that cost-share programs are unlikely to reduce exploitation of ground water and nonpoint-source pollution. By introducing an induced irrigation technology in our model, we find theoretically that the optimal amount of irrigation water and nitrogen fertilizer increases (decreases) when the increased rate of the marginal net economic benefits from their use with an indu...

2005

COMMERCIAL APPLICATIONS From the dawn of civilization until slightly over a century ago, the sole form of irrigation was subsurface. Water was allowed to enter a planted field, and then drained. From Mesopotamia to the Nile Valley to the plains of India, food supplies were irrigated by drainage ditches and natural flooding. Surface water from accumulated rain or snow was the only water source. ...

Journal: :آب و توسعه پایدار 0
علیرضا کیانی فریبرز عباسی

the three practical steps that are need to be taken by government agencies in order to increase irrigation efficiency include economic motivation for optimization of water use, modification of existing irrigation systems in the short term and modernization of traditional methods in the long-term plan. the present research aims at identifying farmers' knowledge regarding irrigation and water iss...

Journal: :سنجش از دور و gis ایران 0
سیدجواد ساداتی نژاد دانشگاه تهران محمدرضا شکاری دانشگاه کاشان

the importance of groundwater as a source of water supply in arid, semi –arid areas in recent years due to the uncontrolled exploitation of groundwater have been doubled. uncontrolled exploitation has been caused a drop in the water table in many areas of the country, including this region. with replace methods of modern irrigation instead of traditional irrigation methods can prevent drop the ...

Journal: :Chemosphere 2007
A Chen C Lin W Lu Y Wu Y Ma J Li L Zhu

An investigation into well water quality was carried out in a rural area subject to irrigation with acidic mine water from the Guangdong Dabaoshan Mine, southern China. The results of water pH measurements from 112 wells in two different seasons suggest that the well water has been contaminated to varying degrees in the investigated Shangba floodplain (approximately 11km south of the Guangdong ...

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