نتایج جستجو برای: increasing trend of dust phenomena

تعداد نتایج: 21188010  

Journal: :تحقیقات جغرافیایی 0
اکبر زهرائی گروه جغرافیای طبیعی دانشگاه سیستان و بلوچستان تقی طاوسی گروه جغرافیای طبیعی دانشگاه سیستان و بلوچستان

abstract: the dust is one of the weather phenomena that have negative environmental effects and consequences. the central city of ahvaz in khuzestan province is one of cities that in every year witnessed the dust in its environment. in this study, after determining that the dust phenomena data are abnormal, using the sen's nonparametric model been proceed to modeling of changes and survey ...

Dust is referred to sediments of less than 100 microns in size which are transmitted as suspended particles. Dust storms are events which naturally occur in arid and semi-arid areas, especially in subtropical latitudes. One of the most known sources of dust is the west of Asia, including Arabian Peninsula, Syria, Iraq, and Iran, especially Khuzestan Province. The purpose of this study is to inv...

Introduction: The occurrence of dust storms in deserts or arid regions increases the suspended dust particles to more than the allowed threshold, and this has negative effects on atmospheric conditions, human health and agricultural production. Positioning of Iran in the world arid and semi-arid belt is exposed to various types of dust storm systems. Occurrence of severe dust storms in most par...

ژورنال: علوم آب و خاک 2020

The occurrence of wind erosion and the spread of dust particles can be regarded as one of the most important and threatening environmental factors. Climate change and the frequency of droughts have played an important role in exacerbating or weakening these events. The primary objective of the present study was to investigate the trend of changes in four important climatic elements (precipitati...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده کشاورزی 1390

abstract previous researches have shown success of growth hormones usage on flower production increase, pod and prevention of abscission of them in some of the pulses. two tests were done, in order to find out the effects of growth hormones to on flower production increase, pod and chick pea yield composites in farmer conditions (2010-11) and green house conditions as factorial on the proje...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید باهنر کرمان - دانشکده ریاضی و کامپیوتر 1389

the concepts of similarity and dissimilarity have been the interest of many researchers. basically, in the studies the similarity between two objects or phenomena, has been discussed. in this thesis, we consider the case when the resemblance or similarity among three objects or phenomena of a set, 3-similarity in our terminology, is desired. later we will extend our definitions and propos...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده ادبیات و علوم انسانی 1390

abstract birbery and corruption and other criminal and as such is one of social phenomena , and i can firmly say that society is protected and safe from harm , this is criminal . eache community is familiar with these crimes and the crime associated ( direct or indirect ) with the political economic , social , and cultural beliefs and religious issues , especially with the community . admitted...

Journal: :محیط شناسی 0
عباسعلی ولی استادیار بیابان زدایی، گروه علوم مهندسی بیابان، دانشکدۀ منابع طبیعی و علوم زمین، دانشگاه کاشان، کاشان، ایران سجاد خاموشی کارشناسی ارشد بیابان زدایی، گروه علوم مهندسی بیابان، دانشکدۀ منابع طبیعی و علوم زمین، دانشگاه کاشان، سید حجت موسوی استادیار ژئومورفولوژی، گروه جغرافیا و اکوتوریسم، دانشکدۀ منابع طبیعی و علوم زمین، دانشگاه کاشان، کاشان، ایران فاطمه پناهی استادیار بیابان زدایی، گروه علوم مهندسی بیابان، دانشکدۀ منابع طبیعی و علوم زمین، دانشگاه کاشان، کاشان، ایران احسان تمسکی کارشناسی ارشد بیابان زدایی، دانشگاه هرمزگان، بندرعباس، ایران

introduction dust storms, one type of dust event, are in most cases the result of turbulent winds, including convective haboobs, which raise large quantities of dust from desert surfaces and reduce visibility to less than 1 km. this dust reaches concentrations in excess of 6000 mg m3 in severe events. the major dust source regions are areas of arid and hyper-arid, with mean annual rainfalls of ...

2009
Mingyuan DU Seiichiro YONEMURA Hiroyuki DEN Zhibao SHEN Yanbo SHEN

Monthly mean air temperature and precipitation data, monthly dust storm frequencies (times of dust storm occurrences) of 107 stations in North China were analyzed to clarify the relationship between the climate change and dust storm occurrence. Arid regions of North China were divided into five and trends of dust storm occurrence and climate changes showed different patterns for these regions, ...

ژورنال: علوم آب و خاک 2022

Dust storms in arid and semi-arid regions have harmful impacts on the environment, the economy, and the health of local and global communities. In this study, the frequency of annual dust events in twenty-five stations and five climatic variables including rainfall, maximum annual wind speed, average annual wind speed, maximum annual temperature, and average annual temperature in arid regions o...

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