• Title/Summary/Keyword: Suspended Sediment

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Comparison of Silt Protector Design Between Korea and Japan (한일간 오탁방지막 설계 비교)

  • 오영민;송원오
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.15 no.1
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    • pp.66-70
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    • 2003
  • Harbor construction works such as dredging, reclamation, riprap dumping and so on generate suspended sediment to affect ocean environment negatively so silt protector is widely used to keep construction site from deteriorating at the moment. This study has a purpose to improve our design techniques by comparing the design procedures of the silt protector between Korea and Japan.

Entrainment and Deposition of Fine-grained Sediments (세립퇴적물 부상과 퇴적에 관한 연구)

  • 강시환
    • Proceedings of the Korea Water Resources Association Conference
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    • 1984.07a
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    • pp.7-21
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    • 1984
  • Entrainment and deposition experiments were counducted in fresh water on four groups of sediments: three well-defined sediments of uniform composition and narrow-size distribution (1 to 9 um, 10 to 50 um, and 50 to 90 um), and a fourth group which was a mixture of these three sediments. In the entrainment experiments and at a particular stress, the steady-state suspended sediment concentration of the coarse group was the lowest while the concentrations of the fine and medium groups were higher that that of the coarse group but were similar to each other. Deposition experiments generally showed an exponential decrease of suspended sediment concentration with time with the decay time being a function of particle size and applied stress.

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Monitoring of the Mobility of Fish on Turbidity Changes (탁도 변화에 따른 어류의 이동 특성 모니터링)

  • Joon Gu Kang;Nam Ju Lee;Dong Ho Nam
    • Ecology and Resilient Infrastructure
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    • v.10 no.4
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    • pp.201-207
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    • 2023
  • Suspended solid in river is resource serious contamination. Suspended solid have a pernicious influence to fish and aquatic ecosystem. Flood and sediment and land use in river are largely[mainly] responsible of suspended solid. Especially, resuspension phenomenon of sediment will be dangerous effect to aquatic ecosystem. Study of fish and aquatic ecosystem on suspended solidus slight in fresh water. This study was basic research to manage fish and aquatic ecosystem on turbidity. It was conducted to analyze and monitor fish response on turbidity. Result in this study was confirmed the insensitive and die of fish on reduction of oxygen supply.

Behavior of Currents and Suspended Sediments around a Silt Screen

  • Jin, Jae-Youll;Chae, Jang-Won;Song, Won-Oh;Park, Jin-Soon;Kim, Sung-Eun;Jeong, Weon-Mu;Yum, Ki-Dai;Oh, Jae-Kyung
    • Ocean and Polar Research
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    • v.25 no.spc3
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    • pp.399-408
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    • 2003
  • The behavior of Suspended Sediment Concentrations (SSC) around a silt screen in a microtidal coastal area was hydrodynamically measured. The current speed at the mid-layer about 30m downstream of the screen reduces to about half that at the same distance upstream. It was caused by the contraction of the vertical section due to the screen. Even during a relatively weak storm period the SSC increases to that of the value caused by dredging. Section-averaged SSC at the downstream of the screen is higher by about 60% than that at the upstream, suggesting that the silt screen plays an adverse effect rather than a constructive role in the reduction of SSC generated by dredging.

Bathymetric Changes in the Nakdong River Estuary owing to Discharge from the Nakdong River Barrier and Environmental Factors (하구둑 방류와 환경적 인자에 따른 낙동강 하구 지역 해저 지형변화 연구)

  • Kim, Ki-cheol;Kim, Sung-Bo
    • Journal of Environmental Science International
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    • v.30 no.7
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    • pp.507-517
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    • 2021
  • In this study, the bathymetric data acquired from 2018 to 2020 and the precipitation and suspended sediment data were analyzed for changes in bathymetry owing to the discharge from the Nakdong River barrier and environmental factors, especially the torrential rain in 2020. Sediment erosion and deposition processes are repeated because of complex environmental factors such as discharge from the Nakdong River barrier and the influence of waves generated from the external sea. In the first half of the year after the dry season, bathymetric data showed relative erosion trends, whereas in the second half after the flood season, deposition trends were identified owing to the increase in sediment transport. However, the data from the second half of 2020 showed a large amount of erosion, resulting in tendencies different to those of erosion in the first half and deposition in the second half of the year. This result is judged to be influenced by the weather in the summer of 2020. The torrential rain in the summer of 2020 resulted in a higher force of erosion than that of deposition. In summary, the tendency for erosion is more significant than that of sedimentation, especially in the main channel area of the Nakdong River.

Susceptibility of Nereocystis luetkeana (Laminariales, Ochrophyta) and Eualaria fistulosa (Laminariales, Ochrophyta) spores to sedimentation

  • Deiman, Melissa;Iken, Katrin;Konar, Brenda
    • ALGAE
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    • v.27 no.2
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    • pp.115-123
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    • 2012
  • The establishment of algal spores plays an essential role in adult kelp distribution and abundance patterns. Sedimentation is a key variable regulating algal spore settlement and success, possibly controlling species-specific dominance $in$ $situ$. Laboratory experiments were used to determine spore attachment and survival rates of two Alaskan canopy-forming kelps, $Nereocystis$ $luetkeana$ (K. Mertens) Postels & Ruprecht and $Eualaria$ $fistulosa$ (Postels & Ruprecht) M. J. Wynne, to various types of sediment loading. Spore attachment for both species was significantly and similarly affected by three sediment treatments: suspended particles; settled sediment covering the substratum; and smothering of attached spores by settling sediment. Spore attachment decreased by approximately 90% at 420 mg sediment $L^{-1}$, the highest sediment load tested here, under all three treatments for both species. These results suggest that increases in sedimentation may constrain the success of the spore stages, but sediment does not seem to be a likely factor explaining species-specific distribution patterns. However, while sedimentation affected spores of both species similarly, timing of spore release in relation to times of maximum sediment load in the water might differ for different species, possibly explaining kelp species distribution patterns.