نتایج جستجو برای: sediment

تعداد نتایج: 36882  

Varied flows such as flooding resulting from dam break can happen due to earthquakes, seepage, bombing, overtopping, mistake in design and project performance as well as causing financial damages and human losses. Unsteady flow during flooding events has a high impact on flow field pattern, sediment motion, ecology and also, distribution of contamination in the river. In this study, the impact ...

2009
Bangqi Hu Zuosheng Yang Houjie Wang Xiaoxia Sun Naishuang Bi Guogang Li

The Three Gorges Dam (TGD) on the upper Changjiang (Yangtze River), China, disrupts the continuity of Changjiang sediment delivery to downstream and coastal areas. In this study, which was based on 54 years of annual water and sediment data from the mainstream and major tributaries of Changjiang, sediment deposition induced by the TGD in 2003–2008 was quantified. Furthermore, we determined the ...

2015
M. Baskaran

Index words: Reservoir sedimentation Pb-210 dating Sediment retention Cs-137 dating The singlemost important factor affecting the longevity of US dams is sedimentation, reducing and perhaps eliminating the reservoir capacity for future sediment storage and floodwave attenuation. A better understanding of the sedimentation rates and sediment dynamics is required for a better management of these ...

2016
James T Liu Zhi-Jun Dai James T. Liu Ya-Ping Lei Xiao-Ling Zhang

DAI, Z.-J.; LIU, J.T.; LEI, Y.-P., and ZHANG, X.-L., 2010. Patterns of sediment transport pathways on a headland bay beach—Nanwan Beach, South China: a case study. Journal of Coastal Research, 26(6), 1096–1103. West Palm Beach (Florida), ISSN 0749-0208. Embayed beaches bounded by headlands, headland bay beaches, are a common feature along the coast of southern China. The patterns of sediment tr...

2016
Emily A. Walsh John B. Kirkpatrick Robert Pockalny Justine Sauvage Arthur J. Spivack Richard W. Murray Mitchell L. Sogin Steven D'Hondt

UNLABELLED Subseafloor sediment hosts a large, taxonomically rich, and metabolically diverse microbial ecosystem. However, the factors that control microbial diversity in subseafloor sediment have rarely been explored. Here, we show that bacterial richness varies with organic degradation rate and sediment age. At three open-ocean sites (in the Bering Sea and equatorial Pacific) and one continen...

Journal: :journal of research in health sciences 0

background: toxaphene is a chlorinated hydrocarbon insecticide. the residues of which have been documented throughout the biosphere including water, ground water, soil and lake sediments, even though its use was banned some years ago. toxaphene has been known as an important environmental pollutant as a result of its persistence in the environment, bioaccumulation and bio magnification in food ...

2015
Daniel Barlow

At present there is a poor understanding of changes in rates of erosion over long time periods and in the link between erosion and sediment delivery in Britain. Using a catchment study approach sediment accumulation rates in cores from the three lakes Semer Water, Gormire and Hornsea Mere have been used to reconstruct changes in sediment yield over time periods of up to 10 000 years, and estima...

Journal: :desert 2015
ali talebi a. bahrami m. mardian j. mahjoobi

managers always consider the precise estimation of sediments in watersheds due to various conditions, such assoil and water resources management, construction, infrastructure and economical and social issues. in this condition,an optimized determination of sediment rating equation (typical method until now for sediment yield estimation) isessential to investigate sediment yield in rivers. in th...

Extended abstract 1- Introduction A bare surface on forest roads is created due to road construction. This surface is the main source of erosion and sediment yield to streams in forest areas. The increase of sediment in streams causes dramatic damage to the quality of water ecosystems and the life of aquatic organisms. Therefore, road engineers should pay attention not only to the cost of roa...

2013
Jie Wang Hiroshi Ishidaira Wenchao Sun Shaowei Ning

Suspended sediment concentration of a river can provide very important perspective on erosion or soil loss of one river basin ecosystem. The changes of land use and land cover, such as deforestation or afforestation, affect sediment yield process of a catchment through changing the hydrological cycle of the area. A sediment rating curve can describe the average relation between discharge and su...

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