• Environmental Analysis Health and Toxicology
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• 제16권4호
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• pp.143-151
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• 2001

Six rivers were selected as preliminary screening sites to determine the test conditions of Microtox in assessing the toxicity of the sediment. In addition, a pH range of 6.0∼6.5 was established in testing pore water, aqueous extracts and organic extracts. Each extractable fraction of sediment showed different toxicities. Therefore, in order to properly examine the toxicity in the sediment, all extractable fractions of sediment samples needed to be tested with Microtox. Thus, sediment samples were additionally collected from at least 4 secondary sites within 50∼100ｍ area of the primary sampling site to reduce any variation or deviation in toxicity assessment. From all sediment toxicity data that was collected from this study, it was concluded that the Keumho river was the most polluted with the highest sediment toxicity of all the rivers analyzed and needed further detailed research on its pollution problem.

• 한국농공학회논문집
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• 제57권6호
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• pp.69-77
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• 2015

The objective of this study was to evaluate the performance of selected sediment reduction methods to reduce sediment discharges from drain and irrigation of different types (concrete canals, soil canals). This study was carried out to analysis for the suspended sediment concentration and sediment of drain and irrigation by velocity of flow. The results of study were analysised and summerized as follow. Sedimentation characteristics and size of soil sediment from the concrete and soil canals of downstream smaller than upstream. Suspended sediment concentration and flow times from the suggestion canals bigger than open canal. Structural shape of the canal decreases the velocity of flow also affects the suspended sediment concentration and flow times.

• 분석과학
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• 제14권3호
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• pp.238-243
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• 2001

K 수계 6개 지점의 호소 퇴적물과 근접된 수질에 대해 $COD_{Mn}$, T-N, T-P, pH를 측정분석 하였다. 퇴적물로부터 분리된 수질이 퇴적물과 근접한 수질보다 COD, T-N, T-P 모두 높은 값을 나타내었으며 그 다음으로 퇴적층 바로 위의 수질이 높은 값을 나타내었다. 직상수와 최상수의 $COD_{Mn}$, T-N, T-P에 대한 수질분석 결과는 1.2~19.0mg/L, T-N, 1.3~6.2mg/L, T-P, 0.05~0.26mg/L의 농도범위를 나타내었다. 이상의 결과로부터 퇴적물이 호소내 수질오염에 영향을 미치는 요인임을 알 수 있었다.

• 한국농공학회지
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• 제38권3호
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• pp.127-136
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• 1996

The purpose of this study is to provide with information for the water resources development and management in stream management planning, such as information on the sediment trensport, design of dam and water facilities, river improvement and flood plains management. The major results obtained from the field measurement and analysis of the watershed characteristics, hydraulic and sediment characteristics are as follows ; 1. The rating curve formulas obtained from the analysis of the hydraulic characteristics data collected are ; Q-=110.563 $(H-0.474)^2$ for 0.7m$(H-0.146)^2$ for 0.4m$Sr=aX{^2} {_1} X^{c}{_2}$, in the experimental watershed.

• 한국수처리학회지
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• 제26권6호
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• pp.43-51
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• 2018

In order to systematically and scientifically manage the organic and heavy metals against sediment at Daecheon Port, this study conducted particle composition, organic materials and heavy metals irradiation studies of sediments. Analysis of the grain size composition of sediments in the target study area showed the distribution characteristics of the mix of sand, silt and clay. That is, Station C (Stn. C) showed superior by fine-grained sediment, Station A and B (Stn. A and B) showed superior by coarse-grained sediment. The organic matter(COD, TOC, and IL) of Stn. C was appeared to be heavily polluted more than Stn. A and B. These data for the spatial properties in sediment showed that organic matter was related positively to the sediment silt-clay content. Also, in the case of heavy metals contamination in surface sediments, Stn. C was higher than Stn. A and B. Particularly, at the Stn. C, high organic matter concentration and C/N ratio value( >10) indicated that the sediment was composed highly of land-derived organic matter. From these results, it considered that the correlation analysis among to silt-clay, organic matter and heavy metal was found to have a good interrelationship.

• 한국환경과학회지
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• 제13권3호
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• pp.263-277
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• 2004

The purpose of this study is to analyze the characteristics of riverbed variation due to the sediment protection weir located on the estuary of the main stream of Taehwa river using I-D finite difference model, HEC-6 model, and the followings are the results of estimating sediment transport rate, amount of scour or deposition, and accumulated amount of deposit according to before and after of the sediment protection weir removal with various flow rates in the channel. Ackers-White transport function produced the greatest sediment transport rate while Meyer-Peter showed the smallest sediment transport rate at the most down stream area of the watershed through the sediment transport rate analyses for various flow rates according to the existence or nonexistence of the sediment protection weir. Toffaleti's and Colby transport function were closest to the average value, and the difference among the results of the sediment transport functions showed up to 8～9 times. Duboy's transport function produced the greatest riverbed variation while Toffaleti's showed the smallest variation through the riverbed variation analyses according to the existence or nonexistence of the sediment protection weir. Yang's was closest to the average value, and the difference among the results of the riverbed variation analyses ranged from 1.4 times to 11 times. It is thought that a sediment transport function must be selected very carefully with respect to the criteria of sediment yield estimation because the analysis results of the sediment transport rate and riverbed variation according to flow rates showed significant differences among the sediment transport functions, and the differences of sediment transport rate and riverbed variation according to the various sediment transport functions decreased as the flow rate increased.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.1576-1580
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• 2006

The destruction of river and damage caused by flood are suddenly increasing due to the abnormal climate. In the investigation result about the damage, approximate 52% of the destruction of embankment are caused by earth work. Moreover, to recover conveyance of relief channel, bed sediment is dredged about 198 millions $m^3$ with 'the project of bed dredging'. So, the concern for bed sediment is the more increasing, the requiring high quality material for banking and the way for application of bed sediment are also the more increasing. In this paper, properties of bed sediment were analyzed through sedimentary mechanism analysis. Moreover, possibility to build embankment with bed sediment in 6 points which is in catchment of the Nak-dong river was also analyzed. At 6 points, which were selected to survey easily, sediment discharge was analyzed with formula. Moreover, size and permeability were analyzed and the feasibility for material of embankment was proposed. If bed sediment wasn't proper, complementary measures were proposed.

• 한국물환경학회지
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• 제29권6호
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• pp.799-807
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• 2013

Reservoir sedimentation is one of the major concerns for sustainable reservoir operation. Since sediment concentration of the rivers in the Himalayan Mountain is very high, a proper sediment management scheme is necessary. This paper presents long-term reservoir sedimentation and sediment flushing based on the gate operation. Focused on the reservoir to be constructed for the Patrind hydropower project in Pakistan, 4 different flushing scenarios were proposed in this study to prevent successive sedimentation. By extending flushing period and by increasing the flushing discharge for 2 times, the flushing rate increases up to 53.2% and 43.6% in proportion to flushing period and discharge, respectively. Based on the simulation presented in this paper, it is expected to establish efficient sediment management plan to increase hydro power generation and sediment flushing simultaneously.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2004년도 학술발표회
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• pp.908-911
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• 2004

The purpose of this study is to investigate the applicability of the two dimensional model in natural rivers. In this study, two dimensional unite element model, SMS, is used to simulate a complex flow along with the sediment movements in the natural river. The RMA-2 model embeded in SMS is used to simulate flow phenomena and SED-2D model is employed to simulate sediment transport. The model is applied to the confluence zone of the Gam River and mouth of Nakdong River. For model calibration, the result of the unsteady flow analysis is compared with the Typhoon 'Rusa' data. In addition, the runoff analysis was conducted for the determination of the project flood and the flood forecasting. The simulation results presented the characteristics of two dimensional flow with velocity vector and flow depth. The sediment transport characteristics are shown in terms of sediment concentration as well as bed elevation change. Accordingly, the SMS model in this study turned out to be very effective tool for the simulation of the hydrodynamic characteristics under the various flow conditions and corresponding sediment transports in natural rivers.

• 한국물환경학회지
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• 제23권5호
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• pp.650-658
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• 2007

The Universal Soil Loss Equation (USLE) has been used in over 100 countries to estimate potential long-term soil erosion from the field. However, the USLE estimated soil erosion cannot be used to estimate the sediment delivered to the stream networks. For an effective erosion control, it is necessary to compute sediment delivery ratio (SDR) for watershed and sediment yield at watershed outlet. Thus, the Sediment Assessment Tool for Effective Erosion Control (SATEEC) was developed to compute the sediment yield at any point in watershed. In this study, the SATEEC was applied to the Sudong watershed, Chuncheon Gangwon to compare the sediment yield using area-based sediment delivery ratio (SDRA) and slope-based sediment delivery ratio (SDRS) at watershed outlet. The sediment yield using the SDRA by Vanoni, SYA and the sediment yield using the SDRS by Willams and Berndt, SYS were compared for the same sized watersheds. The 19 subwatersheds was 2.19 ha in size, the soil loss and sediment yield were estimated for each subwatershed. Average slope of main stream was about 0.86~3.17%. Soil loss and sediment yield using SDRA and SDRS were distinguished depending on topography, especially in steep and flat areas. The SDRA for all subwatersheds was 0.762, however the SDRS were estimated in the range of 0.553~0.999. The difference between SYA and SYS was -79.74~27.45%. Thus site specific slope-based SDR is more effective in sediment yield estimation than area-based SDR. However it is recommended that watershed characteristic need to be considered in estimating yield behaviors.