• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1B
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• pp.33-40
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• 2010

In this study, a two-dimensional hydrodynamic and sediment transport modeling system, HSCTM-2D is employed to simulate the amounts of long-term cohesive sediment deposition in two study bays, and its applicability is evaluated. The modeling system's two modules for hydrodynamic modeling and sediment transport modeling are calibrated, comparing the simulated results and the observed tidal levels, tidal current velocities, and suspended sediment concentrations in the Asan and the Cheonsu Bays, South Korea. It is found that there are good agreements between the simulation results and the observed values. The amounts of long-term cohesive sediment deposition of the two study bays are estimated using the modeling system, taking the suspended sediment concentrations from the open ocean in the tide-dominated environment into account. And, in the case of the Asan Bay, the annual deposition rate reaches 8.1 cm/yr; the Cheonsu Bay, 14.5 cm/yr. Overall, it is concluded that the modeling system is useful to understand the physical process of cohesive suspended sediment transport and deposition in tidal water bodies and to establish the mitigation strategy.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.86-86
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• 2022

While estuarine dams can develop freshwater resources and block the salt intrusion, they can result in increased sediment deposition in the estuary. The mechanism of increased sediment deposition in an estuary with an estuary dam is not well understood. To fill this knowledge gap, 7 ADCP measurements of flow and suspended sediment concentration (SSC) were collected along-channel in an estuary with an estuarine dam over a neap-spring cycle. Flow and SSC were used to calculate the sediment flux and sediment flux gradients. The results indicated that the cumulative sediment fluxes at all stations were directed landward. The along-channel sediment flux gradient was negative, which indicated deposition along the channel. The landward mean-flow fluxes were dominant in the deep portion of the channel near the estuary mouth, whereas landward correlation fluxes were dominant in the shallow portion of the channel near the estuarine dam. The tides were the dominant forcing driving the sediment fluxes throughout the estuary.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.1 s.24
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• pp.67-72
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• 2007

A model for predicting potentials of land erosion and deposition over a natural basin was developed based on the mass balance principle. The program was developed based on sediment mass balance principle for each cell in a GIS. Sediment yield from a cell was estimated with RUSLE. The outflow sediment from a cell was calculated by multiplying the sediment yield of the cell by the sediment delivery ratio (SDR) of the cell. The outflow sediment from the upstream cell becomes the incoming sediment of the downstream cell. Therefore the erosion and deposition potential of each cell could be determined from the sediment mass balance i.e., the difference between the incoming and outflow of sediments of each cell. The developed model was validated by comparing the predicted sediment yields for three basins with measured data.

• Journal of Korea Water Resources Association
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• v.46 no.5
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• pp.531-545
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• 2013

This paper was considered on the applicability of EFDC KUNSAN_SEDTRAN MODEL (2012) to calculate Gunsan Port sediment deposition height efficiently and to use for grasping its aspects quantitatively and providing its prevention measures reasonably based on well-known 3-dimensional EFDC sediment transport module. This model was calibrated and verified with various measured field data of A Report of Hydrological Variation on Kum River Estuary (2004). Due to the model calibration and relevant literature investigation for cohesive sediment parameters, settling velocity (WS), critical deposition stress (TD), reference surface erosion rate (RSE), critical erosion stress (TE) were identified as 2.2E-04m/s, 0.20 $N/m^2$, 0.003 $g/s{\cdot}m^2$, 0.40 $N/m^2$ respectivly on this model. In order to examine the applicability and precision of the model computation, the calculated model data of sediment deposition height at 13 stations for 71 days and suspended-sediment concentration at 2 stations, inner port and outer port for 15 days were compared and analyzed with the measured field data. As a result, the model applicability for sediment deposition height simulation was evaluated as NSE coefficient 0.86 and the precision for suspended-sediment concentration computation was evaluated as time averaged relative error (RE) 23%.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.287-295
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• 2021

As facilities such as dam reservoir wetlands and agricultural irrigation reservoir wetlands are built, sedimentation occurs over time through erosion, sedimentation transport, and sediment deposition. Sedimentation issues are very important for the maintenance of reservoir wetlands because long-term sedimentation of sediments affects flood and drought control functions. However, research on resignation has been estimated mainly by empirical formulas due to the lack of available data. The purpose of this study was to calculate and compare the sediment deposition rate by developing a multiple regression model along with actual data and empirical formulas. In addition, it was attempted to identify potential causes of collapse by applying it to 64 reservoir wetlands that suffered flood damage due to the long rainy season in 2020 due to reservoir wetland sedimentation and aging. For the target reservoir, 10 locations including the GaGog reservoir located in Miryang city, Gyeongsangnam province in South Korea, where there is actual survey information, were selected. A multiple regression model was developed in consideration of physical and climatic characteristics, and a total of four empirical formulas and sediment deposition rate were calculated. Using this, the error of the sediment deposition rate was compared. As a result of calculating the sediment deposition rate using the multiple regression model, the error was the lowest from 0.21(m³km²/yr) to 2.13(m³km²/yr). Therefore, based on the sediment deposition rate estimated by the multi-regression model, the change in the available capacity of reservoir wetlands was analyzed, and the effective storage capacity was found to have decreased from 0.21(%) to 16.56(%). In addition, the sediment deposition rate of the reservoir where the overflow damage occurred was relatively higher than that of the reservoir where the piping damage occurred. In other words, accumulating sediment deposition rate at the bottom of the reservoir would result in a lack of acceptable effective water capacity and reduced reservoir flood and drought control capabilities, resulting in reservoir collapse damage.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.4
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• pp.83-91
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• 2018

Land reclamation, coastal construction, coastline extension and port construction, all of which involve dredging, are increasingly required to meet the growing economic and societal demands in the coastal zone. During the land reclamation, a portion of landfills are lost from the desired location due to a variety of causes, and therefore prediction of sediment transport is very important for economical and efficient land reclamation management. In this study, laboratory disposal tests were performed using an open channel, and suspended sediment transport was analyzed according to flow velocity and grain size. The relationships between the average and standard deviation of the deposition distance and the flow velocity were almost linear, and the relationships between the average and standard deviation of deposition distance and the grain size were found to have high non-linearity in the form of power law. The deposition distribution of sediments was demonstrated to have log-normal distributions regardless of the flow velocity. Based on the experimental results, modeling of suspended sediment transport was performed using deep neural network, one of deep learning techniques, and the deposition distribution was reproduced through log-normal distribution.

• Water for future
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• v.9 no.2
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• pp.67-75
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• 1976

With 9 existng reservoirs selected in the Sab-Gyo River Basin, the sedimentation of the reservoirs has been calculated by comparing the present capacity with the original value, which revealed its reduced reservoirs capacity. The reservoirs has a total drainage area of 6,792 ha, with a total capacity of 1,204.09 ha-m, and are short of water supply due to reduction of reservoirs capacity. Annual sedimention in the reservcire is relation to the drainage area, the mean of annual rain fall, and the slop of drainage area. The results of obtained from the investigation are summarized as follow; (1) A sediment deposition rate is very high, being about $9.19{m}^3/ha$ of drainage area, and resulting in the average decrease of reservoir capacity by 19.1%. This high rate of deposition could be mainly attributed to the serve denvdation of forests due to disor derly cuttings of tree. (2) An average unit storage of 415.8mm as the time of initial construation is decreesed to 315.59mm at present, as resultting, we could'nt supply water at 566.24ha. (3) A sediment deposition rate as a relation to the capacity of unit drainage area is as follow; $Qs=1.43 (c/a)^{0.531}$ (4) A sediment deposition rate as a relation to the mean of annval rainfall is as follow; $Qs=672.61 p^{0.024}$ (5) A sediment deposition rate as a relation to the mean slop of drainage area is follow; $Qs=267.21 S^{0.597}$

• Water Engineering Research
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• v.2 no.1
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• pp.49-61
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• 2001

A grid-based KIneMatic wave soil-water EROsion and deposition Model(KIMEROM) that predicts temporal variation and spatial distribution of sediment transport in a watershed was developed. This model uses ASCII-formatted map data supported from the regular gridded map of GRASS (U.S. Army CERL, 1993)-GIS(Geographic Information Systems), and generates the distributed results by ASCII-formatted map data. For hydrologic process, the kinematic wave equation and Darcy equation were used to simulated surface and subsurface flow, respectively (Kim, 1998; Kim et al., 1998). For soil erosion process, the physically-based soil erosion concept by Rose and Hairsine (1988) was used to simulate soil-water erosion and deposition. The model adopts single overland flowpath algorithm and simulates surface and subsurface water depth, and sediment concentration at each grid element for a given time increment. The model was tested to a 162.3 $\textrm{km}^2$ watershed located in the tideland reclaimed ares of South Korea. After the hydrologic calibration for two storm events in 1999, the results of sediment transport were presented for the same storm events. The results of temporal variation and spatial distribution of overland flow and sediment areas are shown using GRASS.

• International Journal of Ocean System Engineering
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• v.1 no.4
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• pp.185-191
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• 2011

This research was described the prevention of coastal topographical change and sediment diffusive concentration incoming from small estuary after construction jetties. This structure is constructed to decrease sediment deposition incoming from the upstream river due to the urbanization and industrial development and to minimize effects on the coastal ecosystem. The physical modeling and numerical modeling for waves were conducted to analyze the configuration of Imrang sand beach deformation without and with construction of jetty. The specification of the installed jetty, which is able to control sedimentation concentration was decided based on the prediction of the Imrang beach area changes by space and time. As a result, the jetties constructed in the estuary retarded the rate of sand sediment, so that the effect area of sand sedimentation was obviously decreased. In addition, the measured field data indicated that the sediment deposition inside of dikes could be controlled and the right side area of jetties could be preserved without sediment deposition.

• Journal of Environmental Science International
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• v.9 no.1
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• pp.35-42
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• 2000

In this study, the movable bed model testing was carried out so as to analyze bed profile changes including predicting scouring and deposition of bed profile and to solve hydraulic problems affecting with bed and both-bank between upstream and downstream of intake weir in the Nakdong river channel. The movable bed model testing consists of fundamental test, movable model test and numerical analysis method respectively. The fundamental test was enforced to analyze relationship of discharge and sediment load in the tilting flume. When the movable model test was worked, it was shown that sediment budget between input sediment load and output sediment load was balanced exactly. As a result of movable model test, it was presented that scouring and deposition changes in quantities between the upstream and downstream of modification weir were less than those of nature and planning weir. Finally, numerical analysis method was operated by 1-dimensional bed profile changes model ; HEC-6 model so as to complement unsolving hard problems during movable model test. So, modification weir will sustained the stable bed profile changes than any other weirs in the study channel.