نتایج جستجو برای: amount of sediment

تعداد نتایج: 21168937  

2016
James T. Morris Donald C. Barber John C. Callaway Randy Chambers Scott C. Hagen Charles S. Hopkinson Beverly J. Johnson Patrick Megonigal Scott C. Neubauer Tiffany Troxler Cathleen Wigand

A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes that the bulk volume of sediment equates to the sum of self-packing volumes of organic and mineral components or BD = 1/[LOI/k1 + (1-LOI)/k2], where k1 and k2 are the self-packing densities of the pure organic and inorganic compo...

ژورنال: علوم آب و خاک 2017

Effective soil conservation requires a framework modelling that can evaluate erosion for different land-use scenarios. The USLE model was used to predict the reaction of appropriate land-cover/land-use scenarios in reducing sediment yield at the upland watershed of Yamchi Dam (474 km2), West Ardabil Province, Iran. Beside existing scenario, seven other land-use management scenarios were determi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان 1390

cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...

Journal: :Ambio 2014
Yafeng Wang Liding Chen Yang Gao Shuai Wang Yihe Lü Bojie Fu

Check-dams are the most common structures for controlling soil erosion in the Loess Plateau. However, the effect of check-dams on carbon sequestration, along with sediment transport and deposition, has not been assessed over large areas. In this study, we evaluated the carbon sequestration function of check-dams in the Loess Plateau. The results indicate that there were approximately 11 000 che...

استاد عسگری, منصور , شفاعی بجستان, محمود ,

The application of “Modified Einstein Procedure” is recommended by the Specialized Committee on Sediment, Iranian Ministry of Energy. However, this method has not been applied to any river in the country. It is the purpose of this study to investigate the total sediment load of the Karun and Karkheh rivers at Ahwas and Hamidieh stations. The graphical calculations of the method are very complic...

ژورنال: علوم آب و خاک 2022

Splash (raindrop) erosion plays an significant role in soil loss, especially in arid and semi-arid regions with poor vegetation. In this paper, by analyzing the pattern of rainfalls that occurred during 26 years in four basins located in Semnan County, their effect on the pattern of eroded sediments from the basin was investigated. Sedimentary layers from the sampling of retarding reservoir sed...

جمالی, علی‌ اکبر, حسن‌ زاده, محمد, دشتکیان, کاظم, مطلب نژاد, علی,

Soil erosion leads to washing topsoil, organic matter and soil fertility will decrease eventually. In order to combat erosion and loss of soil, conservation and watershed sediment generation in the NIR region, based on the WSM modeling was performed to estimate the severity of soil deposits. The model with six factors was scored for each work unit. Usually suitable model for certain areas that ...

موسوی, سیدفرهاد, جلالیان, احمد, صمدی بروجنی, حسین , محمدزاده, احمد ,

One of the most vital problems in the storage and utilization of surface waters for drinking, flood control, hydropower, and agricultural purposes is that of sedimentation in reservoirs and subsequent decline of dam lifetime. The useful lifetime of a dam is defined as the time necessary for approximately 80% of the volume of its initial capacity to be filled by sediments washed in by water. It ...

A Makvandi, A Telvari M Mashal

Using lateral intake is a method of floodwater diverting. In arid and semi-arid areas, floodwatercontains a large amount of sediment that will be carried in to the intakes and it causes a reduction inchannel conveyance. Sediment is almost transported into the intake and it is settled in the upstreamside of lateral channel. Sedimentation in this zone reduces the conveyance of lateral channel and...

ژورنال: اکوبیولوژی تالاب 2020
Pourkhabbaz, Hamid Reza, Cheraghi, Mitra , Hedayatzadeh, Fariba ,

Assessment of heavy metals concentrations in aquatic ecosystems can be effective to taking actions to improve the quality of environmental conditions. Therefore, this study was downed to evaluate the heavy metals pollution in water and sediments of water supply points of water treatments in Ahvaz and Mollasani along Karun River and the effect of physico-chemical parameters on these pollutants c...

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