نتایج جستجو برای: bed rivers

تعداد نتایج: 67553  

Journal: :Frontiers in water 2023

This study investigates the occurrence and dynamics of single row alternate bars forming in a particular reach sand bed Elbe River Germany. Although formation have been intensively investigated literature, there exists only limited number studies focusing on characteristics under complex field conditions. is case for trained rivers, as most previous focused gravel rivers. Moreover, little known...

Journal: :Water research 2002
Philip N Owens Desmond E Walling

The phosphorus content of fluvial sediment (suspended sediment and the < 63 microm fraction of floodplain and channel bed sediment) has been examined in contrasting rural (moorland and agricultural) and industrialized catchments in Yorkshire, UK. The River Swale drains a rural catchment with no major urban and industrial areas, and the total phosphorus (TP) content of fluvial sediment is genera...

2009
Colin P. Stark Efi Foufoula-Georgiou Vamsi Ganti

[1] Bedrock erosion in mountain river channels ultimately sets the erosion rate of the surrounding hillslopes and the rate of sediment supply to the channels. The supply of coarse bed sediment acts as a dampening effect on further erosion by depositing an alluvial cover that temporarily obscures the bedrock. For landscapes where the residence time of the alluvial bed cover is comparable to the ...

1993
THOMAS E. LISLE

Gravel bed channels have a much greater capacity than sand bed channels to regulate the mobility of the bed surface through the formation of a surface layer of bed particles that is coarser than the particles supplied as load. The coarse surface layer affects bed mobility in two important ways. First, it reduces differences in mobility between coarser and finer particles on the bed surface by m...

2011
F. Rostami M. Shahrokhi S. R. Sabbagh - Yazdi

Undular hydraulic jumps are illustrated by a smooth rise of the free surface followed by a train of stationary waves. They are sometimes experienced in natural waterways and rivers. The characteristics of undular hydraulic jumps are studied here. The height, amplitude and the main characteristics of undular jump is depended on the upstream Froude number and aspect ratio. The experiments were do...

ژورنال: علوم آب و خاک 2002
ترابی پوده, حسن , قمشی, مهدی ,

Many sediment transport equations have been developed for estimation of the river sediment materials during the past four decades. There are significant differences in the results from these equations when applied to compute sediment transport for a specific river. Therefore, application of an equation for estimation of a river sediment load is not an easy task. In this study, 12 important sedi...

2013
Doan Tuan Linh Trinh Hoang Long Pham Thanh Van Vu Van Manh

With the aim of assessing the impact of sand mining project environmental Lo River, subjects used the method of sediment transport modeling in rivers, using Sand Transport module in the hydrodynamic model Mike 21 for a particular project. The result was to determine the feasibility of a sand mining project on the Lo river. The subject has shown that the effects of sand mining project on the flo...

A. Ardeshir, F. Bahadori and A. Tahershamsi,

In this paper, development of a semi-two- dimensional mathematical model called SDAR is introduced. The model is composed of two principal modules of hydraulics and sediment transport. The newly developed SDAR model has a number of capabilities including determination of sediment transport rate, aggradation - degradation&#10calculation, longitudinal profile and lateral cross–sectional variation...

The dimensions, shapes and the patterns of natural rivers change according to their dynamic properties. These unavoidable changes cause the rivers imbalance and a new balance will be formed.  The around lands will be affected by this dynamic and dangers such as instability of the bed. In this research we used chronological inference method to study Kashkan River morphology. Kashkan river is loc...

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