• Water Engineering Research
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• v.1 no.2
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• pp.137-146
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• 2000

A windows-based software package, named DREDGE, is developed for estimating sediment resuspension and contaminant release during dredging operations. DREDGE allows user to enter the necessary dredge information, site characteristics, operational data, and contaminant characteristics, then calculates an array of concentration using the given values. The program mainly consists of the near-field models, which are obtained empirically, for estimating sediment resuspension and the far-field models, which are obtained analytically, for suspended sediment transport. A linear equilibrium partitioning approach is applied to estimate particulate and dissolved contaminant concentrations. This software package which requires only a minimal amount of data consists of three components; user input, tabular output, and graphical output. Combining the near-field and far-field models into a user-friendly windows-based computer program can greatly save dredge operator's, planners', and regulators' efforts for estimating sediment transports and contaminant distribution.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.2
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• pp.45-55
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• 2006

This study analyze the hydrologic conditions and the effects of selected runoff characteristics as an attempt to estimate the optimal dredge amount for Asan Lake in Korea. The runoff feature was calculated by utilizing the water balance simulation from DIROM (Daily Irrigation Reservoir Operation Model), which allowed changes in landuse to be quantified using remote sensing for 14 years. The distribution of prospective sediment deposits was been tallied based on the changes in landuse, and quantity of incoming sediment estimated. From these findings, we were then able to simulate the fluctuation of water level, gauging the pumping days not already in use, to determine the frequency of the distribution for around the. requirement annual water storage and the changing water level. The optimal dredge amount was calculated on the basis of the distribution of frequency, taking into account the design criteria for agricultural water with the 10-year frequency of resistant capacity.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.216-219
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• 2001

In this study, a hydrocyclone operated by centrifugal force was examined as a part of dredge system of lake sediments. It does not help dehydration of the sediments, but also enables the classification of fine particles in the stable and sanitary treatment. Several experiments were performed focusing on the separation efficiency under the condition of room temperature with virtual sediment samples and simulated particles. As a result of the experiment, it was found that the apex size of the cyclone greatly affected the cut diameter(d$_{50}$), and high density particles were separated more effectively.y.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.3
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• pp.285-294
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• 2003

To select an appropriate sampler for the environmental monitoring survey in coastal waters of Saemangeum, Jeollabuk-do, a macrobenthic sampling was conducted in April 2002. Employed samplers were dredge (type Charcot), a semi-quantitative sampler and Smith-McIntyre (SM) and van Veen grab (VV) as quantitative ones. One haul was tried for dredge and 3 replicates (0.1 ㎡${\times}$3) for SM and W at each of 11 stations. Comparisons of sediment volume in sampler bucket and of precision of biological parameters (i.e., density, biomass, species number and diversity index, H') were made between SM and VV. Sediment volume was significantly different (SM > VV) at p-value of 0.0050 (paired t-test) and, in average, 3 replicate samples of SM and VV satisfied a precision level of 0.2 by applying 4th root transformation. Patterns of observed and expected species numbers and H' were compared. Dredge-VV samples showed higher affinity than any other pair. Several dominant species in the area were underestimated in dredge samples (e.g., polychaete Heteromastus filiformis. Aricidea assimilis etc.). Quantifying the agreement pattern of multi-species responses was accomplished by estimating correlations between similarity matrices. Correlation between dredge and VV was slightly higher, but near-per-fect matches were found in general. Different ranks and composition among principal species lists were presumably linked to the effect of penetration depth that differs among samplers. Lower level of some species' abundance in VV samples (ca. 50％ compared with those of SM) was explained in this context. It seem appropriate to regard the effect as a probable cause of relatively higher correlations in dredge-VV, Overall bio-logica1 features indicated that a better choice could be SM in situations of requiring high data quality. The others work well, however, on observing and defining faunal characteristics and their capability cannot be questionted if we do not expect a first-order quality.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.1
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• pp.101-107
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• 2008

According to the existing research result on the seabed organic sediment, pollutants from the land and the sea contaminate the coastal water and sediment on the seabed. To tackle this problem, we need to dredge organic sediment. In the present paper, the development of removing system of seabed sediment by the difference of water head is researched by experimental method. For the validation of the decompression system, computations for validation are carried out for sediment removing equipment. The performance of inhalation equipment is analysed by some model tests.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.74-79
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• 2005

Many reservoirs have been constructed for sustainable utilization of water resources in Korea. Effective management of water resources in Korea becomes very important in resent years. Especially, the dredging in reservoirs is important for effective water resources management and one in easy water resources security methods. According to "The reservoir dredging mid-long term planning investigation report", it was investigated that 1221 reservoirs need to dredge among 3,288 reservoirs managed by KARICO. And, KARICO made a survey of reservoirs for the sediment and storage change in $2002{\sim}2004$. In results, it was investigated total storage $1,406{\pm}10^6m^3$, effective storage $1,344{\pm}10^6m^3$ in mid-small 2,748 reservoirs and the storage ratio decreased total storage ratio 15.7%, effective storage ratio 4.4%.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.57-61
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• 2004

According to the research result of existing regarding the seabed organic sediment, contamination it flows from the land and the sea become the enemy in the coastal water. It was caused with the summer season water temperature rise and dispersing recall respect advancement. Phosphorus which is a main reason of red tide actual condition came to reveal vast quantity with the facts that it gushes. Specially, in the case of the coastal closing waters and the nursery, as the corpse and the fresh fish washing veterinarian was imbrued, it is the actual condition where is more deepened. Consequently the development of shallow layer dredging method of that suction power which is stabilized is demanded to be able to dredge only the sediment layer which has not become the pressure and is a main reason of being imbrued. The dredging methods using the pressure difference minimize the suction of the seabed sediment. This method is stable that suction power which occurs from guard difference of the guard and the guard of the dredging system inland water. That's why it is possible to sort dredging of the organic sediment ranging in upper layer sediment and it will be able to expect the minimization of dredging quantity. Increase of the expense that it followsin orthocenter with the fact will not grow. Because the pressure difference of the dredger inland water is occurred by the suction power. Maintenance administrative costs are reduced, because the one of smallest dredging system maneuvers and the barge which affixes an integrated operation system is mainly in a resting. To reduce a dredging hour, it will be able to solve in the condensed water as operating the jar guard post.

• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.19-29
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• 2011

In order to assess the influences of bottom sediment on water quality, following measurement were made. (1) Estimations of pollutant loads from the bottom sediment based on mass balance concept, (2) measurements of pollutant concentrations in the sediment to assess the pollution level and influence potential, (3) in situ and laboratory measurements of Sediment Oxygen Demants (SOD) and pollutant load (sediment release) from bottom sediment. Analyses of inflow and outflow loadings using simple mass balance show that there are some variations found according to the pollutants. However, there is no consistent evidence that the sediment can be a source of pollutants. Pollutant concentrations in the sediment range 16~724.8 mg/kg (COD), 1.68 ~12.64 mg/kg (T-P), 5.6~76.8 mg/kg (T-N), 0.32~21.6 mg/kg ($NH_3$-N), 0.092~0.544 mg/kg ($NO_2$-N), 4.8~18.4 mg/kg ($NO_3$-N), and 1.59~11.23 mg/kg ($PO_4$-P). Measured SOD ranges $0.190{\sim}0.802g{\cdot}m^{-2}{\cdot}d^{-1}$ and measured release rate ranges $-1618.42{\sim}10mg/m^2{\cdot}d$(COD), $-12{\sim}16mg/m^2{\cdot}d$(T-P), $-197.37{\sim}140mg/m^2{\cdot}d$(T-N), $0.4{\sim}74.32mg/m^2{\cdot}d$($NH_3$-N), $-2.04{\sim}0.8mg/m^2{\cdot}d$ ($NO_2$-N), $-70{\sim}40mg/m^2{\cdot}d$ ($NO_3$-N), and $-26.11{\sim}28.55mg/m^2{\cdot}d$($PO_4$-P). All study results indicate that bottom sediments in the Seoha weir show only limited effects on the water quality. It implies that sediment dredging is not an effective option or management measure to reduce pollutant loading.

• Journal of Korea Water Resources Association
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• v.34 no.3
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• pp.265-273
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• 2001

In this study, a hydrocyclone operated by centrifugal force was examined as a part of dredge system of lake sediments. It does not help dehydration of the sediments, but also enables the classification of fine particles in the stable and sanitary treatment. Several experiments were performed focusing on the separation efficiency under the condition of room temperature with virtual sediment samples and simulated particles. As a result of the experiment, it was found that the apex size of the cyclone greatly affected the cut diameter(d$_{50}$), and high density particles were separated more effectively.y.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.355-358
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• 2002

A sediments are Integral called as gravel, sand, clay, mineral materials which are settling in bottom layer of reservoir, stream, and oceans from land. In practical problems relations of sediments are flood by decreed of flow capacity and down of water quality. Dredged sediments are composed with constructed material and variety of pollutant compounds. Therefore, it is very much of cost effects in nationally, if development for use of constructed material separated only constructed material within sediments. And it will be continue to the dredge operation of stream sediment for retrofit of water environment and sustainable's after the years. The following results could be obtained : In case of high concentration sediments, sample for design of CDF was shown property of flocculent settling. Assuming that average inflow rate is 1, 000㎥/hr, mean residence time( $T_{d}$), average ponding depth( $H_{pd}$ ), and design surface area for flocculent settling( $A_{df}$ ) were 5 hr, 0.6m, and 15, 750 $m^2$ respectivelyrespectivelyy