نتایج جستجو برای: drought indices are commonly used to quantify and assess drought characteristics. the standardized precipitation index (spi)

تعداد نتایج: 22076607  

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 ...

Journal: :فیزیک زمین و فضا 0
رئوف مصطفی زاده استادیار گروه مرتع و آبخیزداری، دانشکده کشاورزی و منابع طبیعی، دانشگاه محقق اردبیلی محسن ذبیحی دانشجوی دکتری علوم و مهندسی آبخیزداری، عضو باشگاه پژوهشگران جوان و نخبگان، دانشگاه آزاد اسلامی واحد بجنورد

drought indices are commonly used to quantify and assess drought characteristics. the standardized precipitation index (spi), and recently introduced standardized precipitation-evapotranspiration index (spei) are considered as universal meteorological drought indices which allow comparisons of drought conditions across different climate regions. the spi captures anomalies in precipitation, wher...

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...

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...

اصغری سراسکانرود, صیاد, زینالی, بتول, صفریان زنگیر, وحید,

Drought is a concept that is generally understood on a basic level, but is difficult to quantify. Palmer defined a drought as a meteorological phenomenon that is characterized by ‘‘prolonged and abnormal moisture deficiency. A drought can alternatively be broadly defined as a temporary, recurring reduction in the precipitation in an area. Aridity and drought are not synonymous. A...

Journal: :آب و خاک 0
خلیل قربانی علی خلیلی سیدکاظم علوی نژاد غلامرضا نخعی زاده

abstract precipitation is an important variable which is used in definition of drought. based on precipitation amounts, some indices are devised for drought monitoring including, the standardized precipitation index (spi) and the standard index of annual precipitation (siap). each of these drought indices are classified into some classes so that each class descripts a given severity of drought....

2014
ZENGCHAO HAO AMIR AGHAKOUCHAK

Accurate and reliable drought monitoring is essential to drought mitigation efforts and reduction of social vulnerability. A variety of indices, such as the standardized precipitation index (SPI), are used for drought monitoring based on different indicator variables. Because of the complexity of drought phenomena in their causation and impact, droughtmonitoring based on a single variable may b...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده مهندسی 1387

abstract this paper discusses several commonly used models for strategic marketing¹ including market environmental analysis methods (i.e. swot and pest analysis) and strategic marketing tools and techniques (i.e. boston matrix and shell directional policy matrix)and shows how these models may help a firm to achieve its strategic goals. at first, the main reason for doing this research is de...

Journal: :natural environment change 0
khadijeh javan professor, climatology, urmia university, iran mohammad reza azizzadeh lecturer, department of geography, payame noor university, po box 3697-19395, tehran, iran saadi yousefi m.a in physical geography, payame noor university. urmia, iran

drought is one of the most important weather-induced phenomena which may have severe impacts on different areas such as agriculture, economy, energy production, and society. a number of drought indices have been introduced and used in various countries to date. in the current study, four meteorological drought indices including percent of normal precipitation index (pnpi), standard index of ann...

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