نتایج جستجو برای: erosion and sediment model in iran

تعداد نتایج: 21952910  

Journal: :مرتع و آبخیزداری 0
کاظم نصرتی دانشیار گروه جغرافیای طبیعی، دانشکده علوم زمین، دانشگاه شهید بهشتی، ایران سعیده جلالی دانش آموخته ژئومورفولوژی، دانشکده علوم زمین، دانشگاه شهید بهشتی، ایران

identifying sediment sources is one of important factors in selecting of appropriate method of erosion control and soil conservation. the main objective of this study is to estimateuncertainty and contribution of forest roads to sediment yield in ziarat drainage basin, gorgan city using geochemical tracers. for this purpose, 47 soil samples were collected from different sources with different l...

Among the various processes that destroy lands, soil erosion is a complex and hazardous environmental process that constitutes a serious threat to preservation of soil and water resources in Iran and has inflicted its negative effects on the vital ecosystem with the intensified utilization of nature by human beings. The present descriptive and analytic research employed the PSIAC model to study...

ژورنال: آبخیزداری ایران 2020

Transferring mechanic of cohesive sediments are different from non-cohesive sediments. For determining the erosion rate of non-cohesive sediments, physical parameters such as average diameter and density are used, such as average diameter and density. Due to the nature of the cohesive sediments, their erosion rates are determined interrelated with the shear stress of the bed with fixed coeffici...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز - دانشکده ادبیات و زبانهای خارجی 1393

abstract in written mode of language, metadiscourse markers are used commonly to help writers in general and academic writers in particular to produce coherent and professional texts. the purpose of the present study was to compare introduction sections of applied linguistics and physics articles regarding their use of interactive and interactional metadiscourse markers based on the model pro...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه گیلان - دانشکده علوم انسانی 1392

this study investigated how group formation method, namely student-selected vs. teacher-assigned, influences the results of the community model of teaching creative writing; i.e., group dynamics and group outcome (the quality of performance). the study adopted an experimental comparison group and microgenetic research design to observe the change process over a relatively short period of time. ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1389

the quest for power has formed much of the world history especially in 20th and 21st centuries. oil (energy) particularly after industrial revolution has been a tool for conquest and power and has been transformed to a geopolitical issue. from a geopolitical point of view this has been the case for the last two centuries in central asia and caucasus. central asia and caucasus has always been...

BACKGROUND AND OBJECTIVES: The study explored the capability of the geographic information system interface for the water erosion prediction project, a process-based model, to predict and visualize the specific location of soil erosion and sediment yield from the agricultural watershed of Taganibong. METHODS: The method involved the preparation of the fou...

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

abstract the third millennium has started, but the world is facing with serious challenges in achieving international security and peace. various human rights violations have lead the states to find means to protect human rights. also article 55 of the united nations charter introduces the respect to human rights and fundamental freedom as the most suitable ways to realize peace and security. ...

Journal: :محیط زیست طبیعی 0
سادات فیض نیا استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران گلاله غفاری کارشناس ارشد آبخیزداری و عضو گروه پژوهشی مرکز خدمات تخصصی آب و خاک و gis معاونت پژوهش جهاد دانشگاهی واحد کردستان، ایران کیوان کریمی زاده کارشناس ارشد آبخیزداری و عضو گروه پژوهشی مرکز خدمات تخصصی آب و خاک و gis معاونت پژوهش جهاد دانشگاهی واحد کردستان، ایران منیرالسادات طباطبایی زاده دانشجوی کارشناسی ارشد مدیریت مناطق بیابانی، دانشکده منابع طبیعی، دانشگاه تهران، ایران

there is a lack of accurate and correct information about erosion in iran. moreover, there is a big difference between measurements and estimations. sediment is also an important environmental problem which pollutes water physically and chemically and therefore, sediment problem is usually studied as environmental problems. estimation of sediment yield of drainage basins is important for preven...

اسماعیلی, روح اله, خوجه, نصیر, قدوسی, جمال,

According to the importance of loss areas, which have embarrassed a wide region of Golestan province and its important role in formation of the sediment of Gorgan river, more accurate recognition of types of loss erosion seems essential in order to providing necessary function for erosion and sediment problems in them, specially gully erosion. So, in this study we are going to providing regress...

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