نتایج جستجو برای: the reconnaissance drought index in 6

تعداد نتایج: 21360044  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده مهندسی علوم آب 1393

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1390

any change in the refractive index of a laser active medium can lead to serious degradation of beam quality, laser beam modes, laser performance and variation in the intensity distribution. alteration in the refractive index of laser active medium is especially notable in high power lasers. it is clear that in the laser beam production, the pumping agent induces a great amount of heat which...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه زنجان - دانشکده ادبیات و علوم انسانی 1392

abstract the present study investigated the effects of task types and involvement load hypothesis on incidental learning of 10 target words (tws) in junior high schools (jhss) in givi, ardabil. the tasks deployed in this study were two input-based tasks (reading plus dictionary use with an involvement index of 3, and reading plus gap-fill task with an involvement index of 2), and one output-ba...

2013
Ravi Shah V. L. Manekar R. A. Christian N. J. Mistry

There are two types of drought as conceptual drought and operational drought. The three parameters as the beginning, the end and the degree of severity of the drought can be identifying in operational drought by average precipitation in the whole region. One of the methods classified to measure drought is Reconnaissance Drought Index (RDI). Evapotranspiration is calculated using Penman-Monteith...

Journal: :تحقیقات آب و خاک ایران 0
حسین دهبان دانشجوی کارشناسی ارشد مهندسی منابع آب دانشگاه تهران کیومرث ابراهیمی دانشیار گروه مهندسی آبیاری و آبادانی دانشگاه تهران شهاب عراقی نژاد استادیار گروه مهندسی آبیاری و آبادانی دانشگاه تهران

in order to avoid drought effects, it is essential to detect and monitor the spatial andtemporal changes of the phenomenon. in general, drought indices are made use of toachieve the goals. the main aim followed in this paper is to introduce and assess a newdrought index termed mrdi. mrdi (modified reconnaissance drought index) is thencompared with modified standardized precipitation index (mspi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد - دانشکده منابع طبیعی 1392

خشکسالی به عنوان بلای طبیعی و پدیده ای اجتناب‏ناپذیر در مناطق خشک و نیمه خشک که مسائل مدیریت منابع آب امری ضروری است، وقوع می یابد. در دهه های اخیر بین حوادث طبیعی که جمعیت های انسانی را تحت تاثیر قرار داده است، پدیده خشکسالی از نظر فراوانی، شدت، مدت، فضای تحت پوشش، تلفات جانی، خسارت های اقتصادی و اثر های اجتماعی دراز مدت در جامعه، بیشتر از سایر بلایای طبیعی بوده است. بررسی روند شدت خشکسالی در ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ولی عصر (عج) - رفسنجان - دانشکده ریاضی 1389

in this thesis, first the notion of weak mutual associativity (w.m.a.) and the necessary and sufficient condition for a $(l,gamma)$-associated hypersemigroup $(h, ast)$ derived from some family of $lesssim$-preordered semigroups to be a hypergroup, are given. second, by proving the fact that the concrete categories, semihypergroups and hypergroups have not free objects we will introduce t...

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. ...

ژورنال: علوم آب و خاک 2019

Droughts are natural events and could lead to declining surface water quality of regional basin. Understanding the complex impacts of drought may help authorities to monitor changes in different regional basin and to make appropriate decision on development of a river basin management plan. In this study 20 years annual precipitation time series from 1994-2013 from 7 synoptic weather stations l...

ژورنال: علوم آب و خاک 2019

In this study, drought characteristics of Arak, Bandar Anzali, Tabriz, Tehran, Rasht, Zahedan, Shiraz and Kerman stations during the statistical period of 1956 to 2015 were studied by Reconnaissance Drought Index (RDI) and Standardized Precipitation Index. Precipitation and temperature data were needed to calculate RDI. Precipitation data was also required to estimate SPI. In this study, Drinc ...

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