نتایج جستجو برای: three precipitation indices coefficient of variation

تعداد نتایج: 21244399  

Journal: :journal of agricultural science and technology 2011
m. jafari a. hemmat m. sadeghi

external fluted feed rolls are commonly used in grain drills. the fluted feed roll meters a volume of seeds and does not singulate the seeds as do the precision planters; therefore, there will be inherent variation in the number of seeds delivered per unit of time. this research was conducted to investigate the effect of seed meter drive shaft and ground speeds and outlet positions in a grain d...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - پژوهشکده مهندسی فرایند 1395

abstract: mineral scaling in oil and gas production equipment is one of the most important problem that occurs while water injection and it has been recognized to be a major operational problem. the incompatibility between injected and formation waters may result in inorganic scale precipitation in the equipment and reservoir and then reduction of oil production rate and water injection rate. ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سمنان 1392

in the area of vocabulary teaching and learning although much research has been done, only some of it has led to effective techniques of vocabulary teaching and many language learners still have problem learning vocabulary. the urge behind this study was to investigate three methods of teaching words. the first one was teaching words in context based on a traditional method of teaching that is,...

A.A Gholami GH.R Hadarbadi H Ebrahimi H Ghasemi

Of the many climatic events that influence the Earth’s environment, drought is perhaps the one that is most linked with desertification. Drought is the consequence of a natural reduction in the amount of precipitation received over an extended period, usually a season or more in length. Drought monitoring is an essential component of drought risk management. It is normally performed using vario...

Journal: :desert 2014
behnaz asefjah faezeh fanian zahra feizi azam abolhasanizarjo hadi paktinat

drought detecting is a necessary aspect of drought risk management. it is generally performed usingdifferent drought indices that are effectively continuous functions of rainfall and other hydro- meteorologicalvariables. a number of drought indices have been introduced and used in various countries to date. in thecurrent research, four meteorological drought indices including the standardized p...

Journal: Desert 2014

Drought detecting is a necessary aspect of drought risk management. It is generally performed usingdifferent drought indices that are effectively continuous functions of rainfall and other hydro- meteorologicalvariables. A number of drought indices have been introduced and used in various countries to date. In thecurrent research, four meteorological drought indices including the standardized p...

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده ادبیات و علوم انسانی 1390

abstract the variables affecting the nature of reading comprehension can be classified into two general categories: reader’s variables, and text variables (alderson, 2000). despite the wave of research on vocabulary knowledge as reader’s variable, the role of this knowledge in c-test as a text-dependent test and its interaction with lexical cohesion of the test as a text feature has remained a...

امین, پیمان, ملکی نژاد, حسین,

In this study, to evaluate and comparing of drought and wet occurrences, Annual rainfall data related to a 60-year period were used for Kermanshah, Kordestan, Kerman and Yazd provinces. Among the different drought indices, the precipitation-based indices such as, Standardized Precipitation Index (SPI), Percent of Normal Precipitation Index (PNPI), Z-Score Index (ZSI) and Nitzche model were used...

Investigating the variability of the spatial-temporal pattern of rainfall, which can lead to climate change, due to its strong impact, is of interest to various scientists. For this purpose, after receiving the daily precipitation data of 27 stations for the period of 60 years (2010-1951), its quality and the total monthly precipitation and statistics necessary for the continuation of the resea...

    Rainfall prognosis plays an important role in drought management and planning of drinking water and agricultural water resources. Also, Future policies can be tailored to optimize spending and maximum productivity. In this study, the effect of large-scale climatic signals on rainfall in Mazandaran province was investigated. The first, the effect of climatic signals on precipitation simultan...

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