نتایج جستجو برای: dust storms are destructive climate phenomenon which damage farm

تعداد نتایج: 6678340  

   Dust phenomenon is a natural occurrence that occurs widespread in arid and semi-arid regions of the world, especially in the sub-equatorial latitudes. This phenomenon is among the greatest environmental problems in the world. The release of this destructive climatic phenomenon in a scattered manner in the atmosphere varies in size, time and concentration. Since this phenomenon is influenced...

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...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1392

abstract in aggregate, active forms of reactive silica with mineral names are sometimes associated with sand and gravel in concrete mixture. alkali hydroxides originated from alkalis in the cement or other resources form an alkaline silica gel with this reactive silica which becomes swallowed and expanded during time causing damage to concrete. there have been growing researches on alkaline r...

خوش کیش, اسدالله, نصیری, بهروز, نیکبخت, حاتم, یاراحمدی, داریوش,

Abstract Climate change has become a widespread and relatively dominant phenomenon at present. It has affected many atmospheric processes such as rainfall, dust storms, temperature increasing and so for. These changes are very important for the living environment and thus needed to study and understand. Therefore the main objective of this study is to investigate the temporal and spatial variat...

جعفری, سجّـاد , مفیدی, عبّـاس ,

1- Introduction In middle and lower troposphere, the main control factor of weather and climate over the Middle East is a local to regional scale thermal forcing including forcing from high mountains. In this regard, regional scale atmospheric circulation associated with surface forcing has an important role in the occurrence of summer dust storms over the area. Southwest of Iran experiences a...

Journal: :جغرافیا و مخاطرات محیطی 0
فهیمه محمدی سمیه کمالی مریم اسکندری

1. introduction dust phenomenon which occurs in arid and semiarid lands of the world is closely related to climatic characteristics of the region. according to the world meteorological organization (wmo), whenever wind speed exceeds 15 meter per second and horizontal visibility reduces to less than 1 km in a station, dust storm is reported (goudie & mideleton, 2006). great storms are created wh...

Extended Abstract Introduction: Dust storm is a major weather event that plays an important role in the Earth’s atmosphere and ocean surfaces. Dust storms affect marine phytoplankton, soil physical and chemical characteristics in entrainment and deposition areas, climate and radiative forcing, economic loss, and human health. They mostly originate from Introduction: Dust storm is a major weath...

ژورنال: علوم آب و خاک 2015
جعفری, رضا, سلطانی, سعید, مهرابی, شهباز,

Since climate has a major impact on dust generation, it is essential to identify the climatic parameters affecting this phenomenon. In this study, climatic parameters including temperature, relative humidity, rainfall, maximum wind speed and direction were selected and their relationship with visibility data and also dust storm days (recorded at meteorological stations) was analyzed on monthly ...

Journal: :جغرافیا و مخاطرات محیطی 0
محمدرضا محمدپور پنچاه محمدحسین معماریان سید مجید میررکنی

introduction one of the factors that affect the climate of arid and semi-arid areas is dust storm. numerical models are new methods for evaluation of dust storms which can also be used for forecasting dust storms. weather patterns that lead to dust outbreaks can be simulated using computer models that support a wide range of simulations related to the long-range transport, dispersion, and depos...

Introduction: In recent years, frequency and intensity of dust storms have been increased because of human destructive activities and caused significant loss in different aspects of hygienic and health, environmental and socio-economic sections. Therefore, detection and trace of dust storms in shortest time is the first effective step in preparation and implementation of strategic and operation...

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