• Journal of Ocean Engineering and Technology
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• v.17 no.1
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• pp.21-25
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• 2003

해안단애의 형성과 침식에 의한 해안선의 후퇴를 저지하기 위해 방조벽을 설치하여 해빈의 침식 변화과정에 관한 수치모의를 수행하였다. 평균수위의 상승을 동반하는 폭풍해일이 내습하는 경우 평균수위의 상승이 방조벽의 세굴을 가속화시킨다. 그러므로 본 연구는 사빈 해안에 방조벽을 설치하는 경우 해빈 침식의 거동을 예측하는데 이용할 수 있겠다.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.843-853
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• 2021

The objectives of this paper were to simply estimate soil loss levels as caused by wind in reclaimed tidal flat land (RTFL) and the threshold wind velocity in the RTFL. For this experiment, RTFL located at Haenam Bay was selected and a total of 150 soil samples were collected at the Ap horizon from the five soil series. The particle distribution curves, including the limit of the non-erodible particle size (D > 0.84 mm) for each Ap horizon soil, show that the proportions of non-erodible particle sizes that exceeded 0.84 mm were 4.3% (Taehan, TH), 8.9% (Geangpo, GP), 0.5% (Bokchun, BC), 1.6% (Poseung, PS) and 1.4% (Junbook, JB), indicating that the amount of non-erodible soil particles increased with an increase in the sand content. The average monthly, daily and instantaneous wind velocities were higher than the threshold friction velocity (TFV) calculated according to the dynamic velocity (V_d) by Bagnold, while the average monthly wind velocity was lower than those of the TFV suggested by the revised wind erosion equation (RWEQ) and wind erosion prediction system (WEPS). The susceptible proportions of erodible soil particles from the Ap horizon soil samples from each soil series could be significantly influenced by the proportion of sand particles between 0.025 and 0.5 mm (or 0.84 mm) in diameter regardless of the threshold wind velocity. Thus, further investigations are needed to estimate more precisely soil erosion in RTFL, which shows various soil characteristics, as these estimations of soil loss in the five soil series were obtained only when considering wind velocities and soil textures.

• Journal of applied mathematics & informatics
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• v.41 no.1
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• pp.181-192
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• 2023

This work deals with the numerical modeling of dam-break flow over erodible bed. The mathematical model consists of the shallow water equations, the transport diffusion and the bed morphology change equations. The system is solved by central upwind scheme. The obtained results of the resolution of dam-beak problem is presented in order to show the performance of the numerical scheme. Also a comparison of central upwind and Roe schemes is presented.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.392-401
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• 2014

This research was carried out to understand the impact of mountainous torrent on topographical change of slope and sediment volume within a deposit line by dredging of soil erosion control dam. Terrestrial LiDAR surveys were conducted at dredged and non-dredged sites. Terrestrial LiDAR has an advantage on detecting topographical changes easily without demanding workmanship and technical skill for users. The distribution of erodible slope ($20^{\circ}-40^{\circ}$) was higher in non-dredged site than that of dredged site. However, the distribution was higher in dredged site than that of non-dredged site after rainy season. Erosion and deposition appeared regularly in a dredged site, but those occurred irregularly in the non-dredged site. The inflow of soil per square meter was 1.7 times higher in dredged site than that of non-dredged site after rainy season. The difference of rainfall in each site did not affect to soil erosion. The distribution of erodible slope was increased in dredged site than that of non-dredged site after rainy season due to inflow of soil from upper stream caused by dredging.

• Journal of Korea Water Resources Association
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• v.46 no.1
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• pp.25-34
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• 2013

In this study, the development processes of multiple bars in the channels with erodible banks were investigated by double Fourier analysis. The initially straight channels in the experiment flume were widened with eroding the side banks, and the multiple bars were generated and grew due to stalling of the sediment on the bed. The bars migrated downstream and the size of the bars increased with time. The flow was separated around the bars, and the bed and banks near the bars were scoured due to the impinged secondary flow. The morphologic changes were accelerated by the bank erosion, which affected the fluctuations of sediment discharge downstream. The double Fourier analysis of the bed waves showed that 1-1 mode (alternate bar) was dominant at the initial stage of the channel development. As time increased, 2-3 mode (central or multiple bars) was dominant due to the increased width to depth ratio. Moreover, the number of bars in a cross section of the channel were increased due to the non linearity of alternate bars. The width to depth ratio was increased by the bank erosion, which affected the bar migration and the bar wavelength. However, the dimensionless tractive force was decreased by it.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.315-323
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• 1998

Soil aggregate distribution and its relation to wind erosion were examined for the surface soil of the experimental plots for grasses in the New Incheon International Airport, of which soil was reclaimed with sea sands in the Youngjong Island. The soil aggregate with the size between 0.10 and 0.84mm was 74 percents. The 6 percents of the soil aggregates were non-erodible. With this aggregate distribution the wind erodiblity of the soil, I. was $380Mg\;ha^{-1}\;yr^{-1}$ with I value and climatic factor calculated for the dry period from November to May, $45.2Mg\;ha^{-1}\;yr^{-1}$ of the surface soil were estimated to be eroded. The erodible particles with 0.37mm diameter could fly to 17.8, 29.9 and 49.8 meters by saltation at wind speed of 7, 9 and $15m\;s^{-1}$, respectively. The wind erosion could be reduced by increasing vegetation coverage and applying hydrophyllic soil conditioner.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.4
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• pp.207-211
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• 2004

Evaluation of wind erodibility for the Saemangeum Reclamation Project area based on the wind erosion equation, WEQ, was attempted. Climatic factor was calculated with the climatic data for the Kunsan area, and soil erodibility factor was evaluated with the 108 soil samples collected from the project area. The soil erodibility evaluated from the non erodible aggregate percentage greater than 0.84 mm for the soil samples collected was $204.1Mg\;ha^{-1}\;yr^{-1}$ ranged from 50.08 to $642.37ha^{-1}\;yr^{-1}$. The annual climate factor based on the meteorological data in Kunsan was 3.67. The average amount of wind erosion with climate factor C from the climatic data from Kunsan and soil erodibility factor l from the soil in the project area was 7.49 Mg $ha^{-1}$ $yr^{-1}$ ranged from 1.84 Mg $ha^{-1}$ $yr^{-1}$ for silty clay loam soil to 23.57 Mg $ha^{-1}$ $yr^{-1}$ for sandy soil. The intensive wind erosion control should be needed for friable sand and loamy sand soils in the area.