نتایج جستجو برای: desertification is specific phenomenon of arid

تعداد نتایج: 21482172  

Journal: :مرتع و آبخیزداری 0
الهام السادات شکوهی دانش آموخته کارشناس ارشد مدیریت مناطق بیابانی، دانشکده منابع طبیعی، دانشگاه تهران، ایران. غلامرضا زهتابیان استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران. علی طویلی دانشیار دانشکده منابع طبیعی، دانشگاه تهران، ایران.

more than 80% of iran’s area has arid and semi arid climate. therefore, iran is exposed to desertification process. practical activities in controlling desertification must be based on current desertification situation and its severity. based on this theory, evaluating desertification rate indices in khezrabad region was done based on imdpa model. in this research two factors with 10 indices we...

2000
Sheng Gong Li Yoshinobu Harazono Takehisa Oikawa Ha Lin Zhao Zong Ying He Xue Li Chang

Overgrazing is one of the most primary causes of desertification in semi-arid zones of China. From 1992 to 1994 we conducted a grazing experiment in Naiman (lat. 42◦58′N, long. 120◦43′E, 345 m asl), Inner Mongolia, China to elucidate desertification mechanisms. Our experimental field, which was covered with some short grasses, legumes and forbs, included four plots where grazing sheep numbers d...

Journal: :desert 2008
t. shamekhi h. mohammadi kangarani j. l. blanchez

desertification of the arid and semi-arid lands of the world has been proceeding for more than a thousand years.human-induced degradation in these areas is regularly cited as one of the principal causes of desertification.euphrates and tigris basin as the case study of this research in some aspects is almost unique in the world. but thisbasin has been confronted to progressive desertification. ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور مرکز - دانشکده شیمی 1391

dendrimer synthesis strategies now provide virtual control of macromolecular nanostructures as a function of size and surface/interior functionality. these strategies involve the covalent assembly of hierarchical components reactive monomers , branch cells or dendron’s around atomic or molecular cores according to divergent/convergent dendrite branching principles.combinon of two or more dendri...

Extended abstract 1-Introduction Desertification means land degradation in the arid, semi-arid and dry sub-humid regions because of natural or anthropogenic factors. Desertification is accounted as the third most important global challenge after the crisis of water shortage and drought in the 21st century. Desertification is a problem for many countries, especially the developing countries. I...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان - دانشکده ریاضی 1390

abstract: in the paper of black and scholes (1973) a closed form solution for the price of a european option is derived . as extension to the black and scholes model with constant volatility, option pricing model with time varying volatility have been suggested within the frame work of generalized autoregressive conditional heteroskedasticity (garch) . these processes can explain a number of em...

Journal: :desert 2011
m jafari m.a. zare chahouki h. ahmadi h.r. abbasi

one of the characters in iranian model of desertification potential assessment (imdpa) is soil. since soil is very important in the degradation of land, so some indices were determined for this character in order to evaluate desertification potential of arid, semi-arid and dry sub humid areas of iran. the indices included soil texture, deep gravel percentage, soil depth, and ec. to calibrate th...

Journal: :desert 0
m jafari professor, faculty of natural resources, university of tehran, karaj, iran m.a. zare chahouki associate professor, faculty of natural resources, university of tehran, karaj, iran h. ahmadi professor, islamic azad university, science and research branch , tehran, iran h.r. abbasi research instructor, forest, range & watershed management organization, tehran, iran

one of the characters in iranian model of desertification potential assessment (imdpa) is soil. since soil is very important in the degradation of land, so some indices were determined for this character in order to evaluate desertification potential of arid, semi-arid and dry sub humid areas of iran. the indices included soil texture, deep gravel percentage, soil depth, and ec. to calibrate th...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1391

deployable scissor type structures are composed of the so-called scissor-like elements (sles), which are connected to each other at an intermediate point through a pivotal connection and allow them to be folded into a compact bundle for storage or transport. several sles are connected to each other in order to form units with regular polygonal plan views. the sides and radii of the polygons are...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1391

this thesis seeks to present a critical reading of virginia woolf’s mrs. dalloway and michael cunningham’s the hours in terms of an intertextual approach, concentrating on dialogic imagination, negativity, transposition and allusion. this study attempts to evaluate cunninghams perception of woolfs life and work by adopting kristevas conception of intertextuality and her consideration of the hou...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید