نتایج جستجو برای: gravel bed

تعداد نتایج: 52222  

ژورنال: علوم آب و خاک 2017
خالدی درویشان, عبدالواحد, روشان, سید حسین, سلیمانی, کریم, وهاب زاده, قربان,

Sand and gravel mining from the most of our country rivers causes morphological, hydrological and geomorphological changes in these rivers. This study investigates the effects of removal of sand and gravel from the river bed on sedimentological features of Zaremrood River in Mazandaran province. For this purpose, by determining four sections before and four sections after the sand removing poin...

River bed sand and gravel are utilized more than mountain materials due to their availability and closeness to the transit roads and sites of usage. Excessive and non-technical extraction of gravel and sand bring a kind of interference in them, leading to many negative consequences. Therefore, presenting solutions to reduce these impacts and infilling mining pits are essential. In this researc...

2007
Daniele Tonina John M. Buffington

[1] We report the first laboratory simulations of hyporheic exchange in gravel pool-riffle channels, which are characterized by coarse sediment, steep slopes, and three-dimensional bed forms that strongly influence surface flow. These channels are particularly important habitat for salmonids, many of which are currently at risk worldwide and which incubate their offspring within the hyporheic z...

2009
Arvind Singh Fernando Porté-Agel Efi Foufoula-Georgiou

[1] A series of flume experiments were conducted to study the effect of bed form dynamics on the flow over a gravel bed comprising a wide distribution of grain sizes. Instantaneous high‐frequency streamwise flow velocities were sampled using an acoustic Doppler velocimeter at a frequency of 200 Hz, while the simultaneous bed elevations were sampled using sonar transducers at a frequency of 0.2 ...

2016
Kurt Imhoff Marco P. Maneta Andrew Wilcox

Sediment routing in gravel-bed rivers refers to the intermittent transport and storage of bedload particles, where short-duration steps are separated by periods of inactivity. Channel morphology governs sediment routing, but morphologic effects on routing in headwater systems are not well understood compared to lowland systems. RFID tracers are a valuable tool that can be employed to characteri...

Journal: :E3S web of conferences 2023

Erosion and entrainment of material by debris flows determine debris-flow volume growth therefore hazard potential. Recent advances in field, laboratory, modelling studies have distilled two driving forces behind erosion; impact shear forces. A third factor influencing the (relative) importance these is viscosity abundance interstitial fluid flow bed. However, how erosion depend on composition ...

Journal: :رخساره های رسوبی 0
مهدی رضا پورسلطانی مصطفی معینی صالح

no-bahar watershed is located, south of khorasan razavi province. geologically, the study area is a part of central iran zone. the rock units are late mesozoic and cenozoic in age in this watershed. no-babhar watershed includes several channels, which among them, only two main channels, motr-abad and solh-abad, have been studied. these rivers are mostly, braided channel in style, with high grad...

افضلی مهر, حسین ,

Over the past decades, numerous regime formulations, describing channel width, average flow depth and channel slope, have been proposed for gravel-bed rivers. Using the downstream hydraulic geometry measurements from 280 field channels, nine gravel-bed predictive formulations were compared. They are attributed to Bray, Chang, Hey and Thorne, Kellerhals, Neil, Parker and Simons, and Albertson. T...

Journal: :International Journal of Enviornment and Climate Change 2023

An experiment with different filter beds and macrophytes was carried out to study their phytoremediation capacity on the efficiency of domestic wastewater treatment through constructed wetland (CW) from November March 2017-18 at University Agricultural Sciences, Dharwad campus, Karnataka. Twenty combinations involving five types (FB-1: gravel, FB-2: gravel-sand-gravel, FB-3: gavel-sand-brick-gr...

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