نتایج جستجو برای: sediment flow

تعداد نتایج: 514708  

Journal: :تحقیقات آب و خاک ایران 0
سیده کوثر دانش یار دانشجوی کارشناسی ارشد گروه خاک شناسی دانشکدة علوم کشاورزی دانشگاه گیلان حسین اسدی استادیار گروه خاک شناسی دانشکدة علوم کشاورزی دانشگاه گیلان سید علی موسوی مربی گروه مهندسی آب دانشکدة علوم کشاورزی دانشگاه گیلان

the understanding soil erosion processes and the development of accurate erosion prediction models require understanding of detachment, deposition and sediment transport in rills. to evaluate the effect of soil type and flow stream power on the relative importance of flow driven processes of sediment transport, and on the boundary between the processes regarding to particle size, experiments we...

2005
M. J. Helmers D. E. Eisenhauer T. G. Franti M. G. Dosskey

Vegetative filters (VF) are used to remove sediment and other pollutants from overland flow. When modeling the hydrology of VF, it is often assumed that overland flow is planar, but our research indicates that it can be two-dimensional with converging and diverging pathways. Our hypothesis is that flow convergence will negatively influence the sediment trapping capability of VF. The objectives ...

2014
Joel Sholtes Kevin Werbylo Brian Bledsoe

Theoretical approaches to magnitude-frequency analysis (MFA) of sediment transport in channels couple continuous flow probability density functions (PDFs) with power law flow-sediment transport relations (rating curves) to produce closed-form equations relating MFA metrics such as the effective discharge, Qeff, and fraction of sediment transported by discharges greater than Qeff, f1, to statist...

Ahmad Shakibaee Nia Amir Reza Zarrati Mohammad Reza Majd Zadeh Tabatabaee

Most of river engineering problems are complicated and need to be analyzed by three dimensional models of flow and sediment transport. Considering the fact that computers and numerical methods with great ability of flow and sediment transport simulation are developing quickly, using numerical modeling by engineers is inevitable. Nevertheless, before application, numerical models need to be veri...

2012
J. I. Theule

Steep mountain catchments typically experience large sediment pulses from hillslopes which are stored in headwater channels and remobilized by debris-flows or bedload transport. Event-based sediment budget monitoring in the active Manival debris-flow torrent in the French Alps during a two-year period gave insights into the catchment-scale sediment routing during moderate rainfall intensities w...

Journal: :مرتع و آبخیزداری 0
سید حمید رضا صادقی استاد گروه آبخیزداری، دانشکدة منابع طبیعی، دانشگاه تربیت مدرس شیرکوه ابراهیمی محمدی استادیار گروه مرتع و آبخیزداری، دانشکدة منابع طبیعی، دانشگاه کردستان کامران چپی استادیار گروه مرتع و آبخیزداری، دانشکدة منابع طبیعی، دانشگاه کردستان

the behavior of suspended sediment during flood events is not only a function of energy conditions, i.e. sediment is stored at low flow and transported under high flow conditions, but also is related to the variations in sediment supply and sediment depletion. these changes in sediment availability result in so-called hysteresis effects. therefore, hysteresis pattern analysis is of great import...

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The sediment load that is transported by rivers can create numerous problems such as sedimentation in the reservoir and storage capacity reduction, developed load in the rivers, destruction of structures along the river and transfer of pollution. Therefore, an accurate estimate of the sediment load in rivers is absolutely essential for river engineering, reservoir design, sediment transportatio...

2010
BJORN BIRNIR JULIE ROWLETT

We consider the theory of erosion and investigate connections to the theory of optimal transport. The mathematical theory of erosion is based on two coupled nonlinear partial differential equations. The first one describing the water flow can be considered to be an averaged NavierStokes equation, and the second one describing the sediment flow is a very degenerate nonlinear parabolic equation. ...

Journal: :تحقیقات مهندسی کشاورزی 0
مهدی اسمعیلی ورکی استادیار گروه مهندسی آب دانشگاه گیلان جواد فرهودی استاد گروه آبیاری و آبادانی دانشکده آب و خاک پردیس کشاورزی و منابع طبیعی دانشگاه تهران محمدحسین امید دانشیار گروه آبیاری و آبادانی دانشکده آب و خاک پردیس کشاورزی و منابع طبیعی دانشگاه تهران

the hydrodynamic behavior of approaching flow and the amount of sediment entry into right-angled lateral intakes in diversion dams were investigated using a laboratory channel by experimental measurement and observation. the velocity field upstream of the intake in the main channel and before it at the sluice gate was measured at different elevations of flow at different discharge rates of the ...

ژورنال: آبخیزداری ایران 2020

Surface gravel cover is an important factor for contoroling of soil erosion in dry area specially in area that plant can not grow because of excessive dryness and salinity. The objective of this study was investigation effect of different surface gravel cover on runoff and sediment yeild. For this porpose, 36 field plots with 20 meter length and 0.5 meter width at 3 percent slope were construct...

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