نتایج جستجو برای: which causes severe land degradation in arid and semi

تعداد نتایج: 21824699  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده علوم انسانی و اجتماعی 1389

today the image of a permanent skeletal space of cities affected by some forces or mechanisms is put in time with social-economic development and while imposes a new face and perspective to physical anatomy of cities, and prepares field to changes in content and social- economic structures of cities too. simultaneously with quitting villages in order to settle in cities by villagers, the phen...

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشگاه مواد و انرژی - پژوهشکده سرامیک 1392

thermal barrier coatings (tbcs) are used to provide thermal insulation to the hot section components of gas turbines in order to enhance the operating temperature and turbine efficiency. hot corrosion and thermal shocks are the main destructive factors in tbcs which comes as a result of oxygen and molten salt diffusion into the coating. in this thesis atmospheric plasma spraying was used to dep...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ارومیه 1377

the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...

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

the west of esfahan province, iran, is one of the most important agricultural areas throughout the country due to the climate variability and life-giving water of zayanderood river. rice is one of the major and economic crops in this area. the most important climatic elements in agricultural activities which should be considered include temperature, relative humidity, precipitation and wind. so...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده ادبیات 1390

in the name of allah , the compassionate the merciful abstract shath ( blasphemic utterace made during spiritual ) is a complicated concept that deserves reflection in gnosticism and sufism ( mysticism ) and estem and westem scholars have alwaya paid attention to it. although principal essence of gnostic belief is the holy divine law ,gnosticism has pure and unique thoughts . by glancing at t...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده فنی مهندسی 1389

the poor orientation of the restaurants toward the information technology has yet many unsolved issues in regards to the customers. one of these problems which lead the appeal list of later, and have a negative impact on the prestige of the restaurant is the case when the later does not respond on time to the customers’ needs, and which causes their dissatisfaction. this issue is really sensiti...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اصفهان - دانشکده زبانهای خارجی 1390

apart from other aspects, desert is a natural environment and is one of the appealing terrestrial elements. putting its symbolic and fictional senses aside, the term “desert” bears mystic sense more than material sense. in addition to the worlds materialistic experiences, desert has attracted the attention of writers because it creates a kind of inner experience, which returns the individual in...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده زیست شناسی 1388

126 abstract: in this research we studied the effects of cyclic hydration and dehydration of cysts of artemia urmiana and artemia parthenogenetica on the hatching percentage, survival and growth. the experiment was carried out in 3 treatments (1-3 hydration/dehydration cycles) with 3 replicates for each treatment. later effects of cold preservation at -20°c during three time periods were ...

Journal: :اکو هیدرولوژی 0
ناصر طهماسبی پور استادیار گروه مرتع و آبخیزداری، دانشکدۀ کشاورزی، دانشگاه لرستان، خرم‏آباد امید رحمتی دانشجوی دکتری علوم و مهندسی آبخیزداری، دانشگاه لرستان، خرم ‏آباد سمیرا قربانی نژاد دانشجوی کارشناسی‏ ارشد مهندسی آبخیزداری، دانشگاه لرستان، خرم ‏آباد

gully erosion constitutes a major problem in natural resources management and soil conservation, which causes severe land degradation in arid and semi-arid areas. therefore, determination of gully prone area and identification of gully conditioning factors can help to managers and decision makers to reduce the hazard of gully erosion. the aim of this study is to predictthe gully erosion suscept...

Journal: :مرتع و آبخیزداری 0
سید هدایت پروری اصل دانش آموخته کارشناسی ارشد رشته بیابان¬زدایی، دانشکده منابع طبیعی، دانشگاه زابل، ایران احمد پهلوانروی استادیار، دانشکده منابع طبیعی، دانشگاه زابل، ایران علیرضا مقدم نیا استادیار، دانشکده منابع طبیعی، دانشگاه زابل، ایران

desertification is the consequence of series of processes in which climate change and human activities are more important factors than others. arid and semi-arid areas have occupied most parts of iran. sistan region is one of arid areas of iran where wind erosion is an important factor of land degradation and soil deterioration. for classification of desertification intensity, several methods h...

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