نتایج جستجو برای: reference evapotranspiration is an important parameter in irrigation systems

تعداد نتایج: 18288037  

2017
Diofantos G. Hadjimitsis Giorgos Papadavid

Evapotranspiration (ETc) is the mean for exploiting irrigation water and constitutes a major component of the hydrological cycle (Telis et al., 2007; Papadavid, 2011). The ETc is a basic and crucial parameter for climate studies, weather forecasts and weather modeling, hydro‐ logical surveys, ecological monitoring and water resource management (Hoedjes et al., 2008). In the past decades, the es...

2007
S. MOHAN N. ARUMUGAM N. Arumugam

Abstract Evapotranspiration (ET) is an important process in the hydrological cycle and needs to be accurately quantified for proper irrigation scheduling and optimal water resources systems operation. The time variant characteristics of ET necessitate the need for forecasting ET. In this paper, two techniques, namely a seasonal ARIMA model and Winter's exponential smoothing model, have been inv...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بیرجند 1388

a significant problem in multicarrier communication systems is the necessity to reduce the value of papr (peak-to-average power ratio) of transmitting signal. in this thesis we study the effect of the system parameters such as coding and modulation types on papr and ultimate ber in a mc-cdma system. in this study we consider fading channel as well as the nonlinearity of transmitter’s amplifier ...

Journal: :مدیریت آب و آبیاری 0
امیر احمد دهقانی استادیار گروه مهندسی آب، دانشگاه علوم کشاورزی و منابع طبیعی گرگان محمد قبائی سوق دانشجوی کارشناسی ارشد مهندسی منابع آب، گروه مهندسی آب، دانشگاه علوم کشاورزی و منابع طبیعی گرگان حسین شریفان استادیار گروه مهندسی آب، گروه مهندسی آب، دانشگاه علوم کشاورزی و منابع طبیعی گرگان نوید دهقانی دانشجوی کارشناسی ارشد مهندسی آبخیزداری، گروه مهندسی آبخیزداری، دانشکده منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرس

accurate estimation of reference evapotranspiration plays a key role in water resources management and irrigation scheduling. the fao penman-monteith (f-p-m) is a reference method for calculation of evapotranspiration that needs temperature, humidity, wind speed and solar radiation. in many stations, it is not an easy task to measure the whole weather variables. thus, in this situation, one mus...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی خواجه نصیرالدین طوسی - دانشکده مهندسی برق و کامپیوتر 1391

many mobile and off-grid devices include electronics and other electrical consumers like servo drives, which need a quite low supply power. since the price for photovoltaic modules drops continuously, photovoltaic power supply is interesting in more and more applications. in solar powered systems, a battery is needed to store energy for the night and cloudy periods. the power electronics of suc...

Journal: :آب و خاک 0
شریفان شریفان علیزاده علیزاده

abstract in order to estimate the reference evapotranspiration different equation is used. validity of each methods depends upon the climate and the parameters which are used in these equations. therefore it is necessary to calibrate these methods for any specific area and for any desired frequency. in this study common temperature and radiation based methods were used for calculating crop evap...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ارومیه 1377

fuzzy logic has been developed over the past three decades into a widely applied techinque in classification and control engineering. today fuzzy logic control is one of the most important applications of fuzzy set theory and specially fuzzy logic. there are two general approachs for using of fuzzy control, software and hardware. integrated circuits as a solution for hardware realization are us...

Journal: :دانش آب و خاک 0
داود زارع حقی استادیار گروه علوم و مهندسی خاک، دانشگاه تبریز محمدرضا نیشابوری استاد گروه علوم و مهندسی خاک، دانشگاه تبریز ابوالفضل مجنونی هریس استادیار گروه مهندسی آب، دانشگاه تبریز رضا حسن پور دانشجوی دکترای گروه علوم و مهندسی خاک، دانشگاه تبریز شیوا میرزائی دانش آموخته کارشناسی ارشد گروه علوم و مهندسی خاک، دانشگاه تبریز

for estimating plants water requirement at the different stages of plant growth, determination of crop coefficient is very important. therefore, this study was conducted to determine the crop coefficient of borage in research lands of faculty of agriculture at the university of tabriz in 2013. for this purpose, drainage lysimeter with diameter of 1.5 meter and depth of 1.7 meter was used for de...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده فنی مهندسی 1385

acknowledge the importance of e-commerce to their countries and to survival of their businesses and in creating and encouraging an atmosphere for the wide adoption and success of e-commerce in the long term. the investment for implementing e-commerce in the public sector is one of the areas which is focused in government‘s action plan for cross-disciplinary it development and e-readiness in go...

Abiose M. Oguntuase Ayorinde A. Olufayo Johnson T. Fasinmirin, Philip G. Oguntunde,

Amaranthus cruentus, an annual vegetable crop, is known to be highly productive under rain-fed conditions and during the dry season when supplied with water. However, for good water management, there is need to accurately quantify the water consumed by the crop. This paper investigates the water use and biomass yield of differentially irrigated Amaranthus cruentus at different developmental sta...

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