نتایج جستجو برای: bed sediments

تعداد نتایج: 77010  

Journal: :Water 2022

The purpose of the study was to collect experimental data on vertical structure sediment fluxes during wave crest and trough phase over sloped bed. first stage work included measurements these using particle image method, while second stage, transport rates granulometric distributions sediments collected in traps both sides initial area. were compared with results previously flat bed as well a ...

Journal: :فیزیک زمین و فضا 0
همایون خوشروان دکتری تخصصی زمین شناسی، رئیس مرکز ملی مطالعات و تحقیقات دریای خزر، موسسه تحقیقات آب سمیه روحانی زاده کارشناس ارشد رسوب شناسی، کارشناس پژوهشی مرکز ملی مطالعات و تحقیقات دریای خزر جواد ملک کارشناس ارشد مهندسی عمران، مربی پژوهشی موسسه تحقیقات آب قاسم نژادقلی کارشناس ارشد فیزیک دریا، کارشناس پژوهشی مرکز ملی مطالعات و تحقیقات دریای خزر

in this research work the classification of the southern coasts of the caspian sea is performed using sedimentary and morphodynamic indices. this includes field study of morphodynamic characteristics of the shore structures. field measurements include in situ samplings of sediments and actual observations of structures on site. these field activities were done along six transects in the dry coa...

Journal: :E3S web of conferences 2023

Stony debris flow transits to sediment sheet when the river bed gradient becomes gentle. The consists of a water layer and moving layer. Fine sediments are expected behave as part fluid rather than solid phase in Further, it can be thought that fine suspended However, was not possible physically express whether behaves or numerical simulation model. Here we modeled behavior flow. We confirmed a...

ژورنال: اکوبیولوژی تالاب 2019
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Heavy metals tend to be adsorbed and accumulated in sediments as opposed to water or suspended solids. Sediments and biota bodis can act as a final sink for heavy metals in the aquatic environments. They accumulate through the food chain posing potential biological and ecological risks. Therefore, research on the heavy metal concentrations in aquatic ecosystems can help to protect human health ...

Journal: :تحقیقات مهندسی کشاورزی 0
سیدمجتبی رضوی نبوی دانشجوی دکتری سازه های آبی محمود شفاعی بجستان استاد هیدرولیک، دانشکده مهندسی و علوم آب، دانشگاه شهید چمران سیدمحمود کاشفی پور استاد هیدرولیک، دانشکده مهندسی و علوم آب، دانشگاه شهید چمران

grade control structures are hydraulic structures used to stabilize a river bed. scour downstream of this structure is the main cause of its failure. studies have developed numerous empirical relations for scour depth prediction that designers must choose between to decide the most effective equation for a specific application. this study tested the condition of submerged jets over beds of sedi...

Journal: :journal of water sciences research 2013
s.m razavi nabavi m shafai bejestan

rade control structures are used to control bed erosion in steep small rivers mostly in the mountains. scour downstream of this structure can lead to failure. over the past years, the effect of different variables on this phenomena have been studied, however the effect of upward seepage which is common due to head difference of the banks water table or water surface level between the upstream a...

M Shafai Bejestan S.M Razavi Nabavi

rade control structures are used to control bed erosion in steep small rivers mostly in the mountains. Scour downstream of this structure can lead to failure. Over the past years, the effect of different variables on this phenomena have been studied, however the effect of upward seepage which is common due to head difference of the banks water table or water surface level between the upstream a...

Journal: :آب و خاک 0
سیدمرتضی سیدیان محمود شفاعی بجستان

abstract lateral intake is a hydraulic structure which is used for diversion of some portion of water from a river for the purpose of irrigation, storage and industrial. most of lateral intakes from canal are installed at canal with inclined banks which has not received the attention of the researchers in the past. since the flow discharge and sediment which enters the intake canal depends on t...

Journal: :تحقیقات مهندسی کشاورزی 0
جمال محمدولی سامانی دانشیار دانشکدة کشاورزی دانشگاه تربیت مدرس سیدعلی ایوب زاده استادیار دانشکده کشاورزی دانشگاه تربیت مدرس روزبه آقامجیدی دانشجوی کارشناسی ارشد دانشکده کشاورزی دانشگاه تربیت مدرس

control of sedimentation in dam reservoirs is considered to be one of the most important issues in exploitation of dams and increasing the their useful life. reservoirs act as traps for sediments and prevent transport of sediment to the river. the deposited sediment decreases the capacity of reservoirs so that they can not be in use any more. various methods dealing with removing part of the de...

2002
R. M. Carter

The Merced Formation comprises a 2-km-thick shallow marine and non-marine succession that was deposited in a small transtensional basin along the San Andreas Fault during the late Pliocene to middle Pleistocene. The sediments dip between 10j and 80j to the northeast, and are locally disrupted by small faults. During tilting, the beds have been rotated into subparallelism with the San Andreas Fa...

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