نتایج جستجو برای: suspended sediment formulae

تعداد نتایج: 71491  

Journal: :محیط زیست طبیعی 0
سادات فیض نیا استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران گلاله غفاری کارشناس ارشد آبخیزداری و عضو گروه پژوهشی مرکز خدمات تخصصی آب و خاک و gis معاونت پژوهش جهاد دانشگاهی واحد کردستان، ایران کیوان کریمی زاده کارشناس ارشد آبخیزداری و عضو گروه پژوهشی مرکز خدمات تخصصی آب و خاک و gis معاونت پژوهش جهاد دانشگاهی واحد کردستان، ایران منیرالسادات طباطبایی زاده دانشجوی کارشناسی ارشد مدیریت مناطق بیابانی، دانشکده منابع طبیعی، دانشگاه تهران، ایران

there is a lack of accurate and correct information about erosion in iran. moreover, there is a big difference between measurements and estimations. sediment is also an important environmental problem which pollutes water physically and chemically and therefore, sediment problem is usually studied as environmental problems. estimation of sediment yield of drainage basins is important for preven...

Journal: :مرتع و آبخیزداری 0
الهام کاکائی لفدانی دانشجوی دکتری علوم و مهندسی آبخیزداری، دانشکده منابع طبیعی، دانشگاه تربیت مدرس، نور، ایران علیرضا مقدم نیا دانشیار گروه احیای مناطق خشک و کوهستانی، پردیس کشاورزی و منابع طبیعی کرج، دانشگاه تهران، کرج، ایران آزاده احمدی استادیار دانشکده مهندسی عمران، دانشگاه صنعتی اصفهان، اصفهان، ایران حیدر ابراهیمی دانشجوی دکتری علوم و مهندسی آبخیزداری، گروه آبخیزداری، دانشگاه کاشان، کاشان، ایران

this study aimed to examine the influence of pre-processing input variables by gamma test on performance of support vector machine in order to predict the suspended sediment amount of doiraj river, located in ilam province from 1994-2004. the flow discharge and rainfall were considered as the input variables and sediment discharge as the output model. also, the duration of the model training pe...

Journal: :Environmental research 2007
David H Schoellhamer Thomas E Mumley Jon E Leatherbarrow

Water-quality managers desire information on the temporal and spatial variability of contaminant concentrations and the magnitudes of watershed and bed-sediment loads in San Francisco Bay. To help provide this information, the Regional Monitoring Program for Trace Substances in the San Francisco Estuary (RMP) takes advantage of the association of many contaminants with sediment particles by con...

2012
Raj Mohan Singh

The observation of peak flows into river or stream system is not straight forward but complex function of hydrology and geology. Accurate suspended sediment prediction in rivers is an integral component of sustainable water resources and environmental systems modeling. Agricultural fields’ fertility decays, rivers capacity decreases and reservoirs are filled due to sedimentation. The observatio...

2017
I. Kozhevnikova L. Bjørnø

Maritime advances during recent years have shown the importance of and the need for development of ultrasonic methods for the investigation of the transport of suspended marine sediments in rivers and in coastal regions. Two main acoustical procedures have been developed and used for the investigations of suspended sediment qualities during the laboratory studies, (1) high frequency resonance b...

2004
Peter T. Harris Michael G. Hughes Elaine K. Baker Robert W. Dalrymple Jock B. Keene

Current metre deployments, suspended sediment measurements and surface sediment samples were collected from three locations within distributary channels of the tidally dominated Fly River delta in southern Papua New Guinea. Net bedload transport vectors and the occurrence of elongate tidal bars indicate that mutually evasive ebband flooddominant transport zones occur in each of the distributary...

, , hezarkhani, najmeye, sepahvand, alireza,

Being available the accurate data on carried sediment has accounted as an important factor for making decision about constructing of river structures and determining of dam life. To accomplish this object, a number methods have been proposed so that sediment rate curving as a hydrological method has been developed for doing it. Ignoring differences between season's values causes to lower the pr...

2017
Anthony Reisinger James C. Gibeaut Phillippe E. Tissot

Suspended sediment dynamics of Corpus Christi Bay, Texas, USA, a shallow-water wind-driven estuary, were investigated by combining field and satellite measurements of total suspended solids (TSS). An algorithm was developed to transform 500-mModerate Resolution Imaging Spectroradiometer (MODIS) Aqua satellite reflectance data into estimated TSS values. The algorithm was developed using a reflec...

2007
S. Grauso

An application of regression relationships depending on geomorphic parameters is proposed to predict the amount of the average annual suspended sediment yield at different sections of the drainage network. Simple and multiple regression relationships, utilising the drainage density and the hierarchical anomaly index as independent variables, based on data from 20 river basins of different size ...

2000
Jing Lou David J. Schwab Dmitry Beletsky Ann Arbor Nathan Hawley

A quasi-three-dimensional suspended sediment transport model was developed and generalized to include combined wave-current effects to study bottom sediment resuspension and transport in southern Lake Michigan. The results from a threedimensional circulation model and a wind wave model were used as input to the sediment transport model. Two effects of nonlinear wave-current interactions were co...

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