• Journal of the Korean Professional Engineers Association
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• v.32 no.4
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• pp.81-87
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• 1999

• Journal of Environmental Science International
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• v.17 no.1
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• pp.29-36
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• 2008

A large amount of $2.1{\times}10^6m^3$ of polluted sediment was dredged from the Masan Bay and deposited in Gapo confined area, Masan, Korea. The six representative sediments were obtained and analyzed for issue components. The data was discussed with the species of benthos and their distribution. It was judged that toxicological effects of sediment analyzed ranged from ERL to ERM with copper and zinc, and ERL with cadmium, chrome, lead and nickel by the Adverse Biological Effects. The dredging index (DI) of sediments stabilized for 10 years since dumping the confined site was calculated and compared with the DI values of dredged sediment itself. DI values decreased from 0.67 to $0.07{\sim}0.18$, which reflects DI value less than 0.2 is good for benthos in the sediment by the natural recovery of dredged materials. The ecological recovery was confirmed in this confined area as a habitat of benthic organisms.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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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.

• 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 Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.179-184
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• 2003

It is inevitable for dredging to increase the suspended sediment concentration (SSC) of the ambient waters in some degree, which has the potential to affect the coastal ecosystem in various manners. Thus, quantitative under- standing of dredging-induced sediment loss is essential fur the reliable environmental impacts assessment. (omitted)

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.74-86
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• 2008

To assessment the disturbances of the Namgang caused by dam construction, upstream area was selected for the reference reach and downstream area was selected for the comparison reach. And these reaches were surveyed and analyzed according to the assessment criteria of the river disturbances.The artificial factors of river disturbances were classified as river improvement works, dam construction and aggregate dredging. The indexes were physical factors as like epifaunal (bottom), embeddedness, velocity/depth regime, sediment deposition, channel flow status, channel alteration, frequency of riffles, bank stability, vegetative protection, riparian zone etc.The assessment results showed 46% of the assessment criteria which was serious status in dam downstream area and 89.5% of it which was excellent status in dam upstream.Finally, the results showed that physical river environment in downstream area was disturbed by the discharge control and the interception of sediment discharge by dam, consequently this disturbance give rise to impact of ecosystem in river.

• Smart Structures and Systems
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• v.26 no.6
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• pp.781-796
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• 2020

Prediction of total sediment load is essential in an extensive range of problems such as the design of the dead volume of dams, design of stable channels, sediment transport in the rivers, calculation of bridge piers degradation, prediction of sand and gravel mining effects on river-bed equilibrium, determination of the environmental impacts and dredging necessities. This paper is aimed to investigate and predict the total sediment load of the Wadi Arbaat in Eastern Sudan. The study was estimated the sediment load by separate total sediment load into bedload and Suspended Load (SL), independently. Although the sediment records are not sufficient to construct the discharge-sediment yield relationship and Sediment Rating Curve (SRC), the total sediment loads were predicted based on the discharge and Suspended Sediment Concentration (SSC). The turbidity data NTU in water quality has been used for prediction of the SSC in the estimation of suspended Sediment Yield (SY) transport of Wadi Arbaat. The sediment curves can be used for the estimation of the suspended SYs from the watershed area. The amount of information available for Khor Arbaat case study on sediment is poor data. However, the total sediment load is essential for the optimal control of the sediment transport on Khor Arbaat sediment and the protection of the dams on the upper gate area. The results show that the proposed model is found to be considered adequate to predict the total sediment load.

• Journal of Environmental Policy
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• v.9 no.2
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• pp.41-55
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• 2010

This paper analyzes optimal watershed management focusing on reservoir-level sediment removal techniques. Although dams and reservoirs provide several benefits, sedimentation may reduce their storage capacity. As of today, the Aswan High Dam (AHD) in Egypt faces approximately 76% reduced life of the reservoir. Since the AHD is the major fresh water source in Egypt, sustainable use of this resource is extremely important. A model is developed to simultaneously determine optimal sediment removal strategies for upstream soil conservation efforts and reservoir-level sediment control. Two sediment removal techniques are considered: mechanical dredging and hydro-suction sediment removal system (HSRS). Moreover, different levels of upstream soil conservation efforts have introduced to control soil erosion, which is a major contributor of reservoir storage capacity reduction. We compare a baseline case, which implies no management alternative, to non-cooperative and social planners' solution. Our empirical results indicate that the socially optimal sediment removal technique is a mechanical dredging with unconstrained amount with providing a sustainable life of the reservoir. From the empirical results, we find that social welfare can be as high as $151.01 billion, and is sensitive to interest rates and agricultural soil loss.

• Journal of Soil and Groundwater Environment
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• v.15 no.2
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• pp.47-54
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• 2010

Although the demands for the dredging work have been increasing due to social and industrial reasons including national plan for restoration of four major rivers, environmental standards or management guidelines for the dredged river sediment are limited. The suggested environmental standard for the beneficial use of dredged river sediment consists of two levels, recyclable and concern, and includes eight contaminants such as metals and organic contaminants. The systematic approach to remediate dredged river sediment is also suggested. The system consists of both washing and stabilization processes with continuous multi particle separation. In the early stage, the sediments are separated into two particle sizes. The coarse-grained sediment over 0.075 mm, generally decontaminated with less trouble, follows normal washing steps and is sent for recycling. The fine-grained sediments under 0.075 mm are separated again at 0.025 mm. The particles bigger than this second separation point are treated in two ways, advanced washing for highly contaminated sediments and stabilization for less. The lab test results show that birnessite and apatite are most effective stabilizing agents among tested for Cd and Pb. The most fine residues, down-sized by continuous particle separation, are finally sent for disposal. The system is tested for metals in this study, but is expected to be effective for organic contaminants included in the environmental standard, such as PAH and PCE. The feasibility test on the field site will be followed.

• Journal of Korea Water Resources Association
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• v.37 no.6
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• pp.467-477
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• 2004

Effective management of water resources in Korea becomes very important in recent years. Especially, the management of reservoirs cannot be over emphasized. The status of sediment deposit and the dredging records of agricultural reservoirs were examined to find out at e reservoir retention capacity could be raised more than 10% of the total volume of reservoirs in Kyungbook Province. Sediment prediction methods were developed by combining the estimation mothods of geomorphological characteristics and upslope contribution area in GIS, The estimated sediment depsit amount were compared with the dredging records for three agricultural reservoires. It was found that the distributed model with ‘Flow accumulation’ and ‘Multiple Flow Direction Algorithm’ gives good prediction results for mountaineous area.