• 한국물환경학회지
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• 제22권6호
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• pp.1094-1100
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• 2006

In this study, the reservoir sediment reduction methods for long-term operation are proposed by the analysis of both sediment deposit characteristics and sediment reduction effect by each method. To that end, a flowchart for sediment analysis in reservoir is established and sediment deposit is simulated by SMS-SED2D model. The sediment reduction methods which are sediment passing (sluicing), flushing, trapping, bypassing and mechanical removal are used. From the simulation results, the effective method for sediment reduction is operation which is coupled by both sediment passing with sand gate and sediment trapping with debris dam. And If sediment flushing will be used once a year after 50 years, conservation storage can be secured until 100 years after dam construction.

• 한국물환경학회지
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• 제31권4호
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• pp.407-417
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• 2015

Soil loss is one of the significant disasters which have threatened human community and ecosystem. Particularly, Korea has high vulnerability of soil loss because rainfall is concentrated during summer and mountainous regions take more than 70% of total land resources. Accordingly, the sediment control management plan are required to prevent the loss of soil resources and to improve water quality in the receiving waterbodies. In this regard, the objectives of this study are 1) to quantify the effect of the Vegetative Filter Strip (VFS) on sediment runoff reduction and 2) to analyze the relationship of rainfall intensity and sediment runoff. For this, SATEEC and VFSMOD were used to estimate sediment runoff according to rainfall intensity and to quantify the effect of VFS on sediment runoff reduction, respectively. In this study, the VFS has higher impact on sediment reduction for lower maximum rainfall intensity, which means that the maximum rainfall intensity is one of significant factors to control sediment runoff. Also, the sediment with VFS considered was highly correlated with maximum rainfall intensity. For these results, this study will contribute to extend the applicability of VFS in establishing eco-friendly sediment control plans.

• 한국물환경학회지
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• 제26권2호
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• pp.215-224
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• 2010

This study was carried out to estimate effects of sediment reduction with net type sediment settling pond at highland agricultural areas. Flow and sediment monitoring system with rainfall gauge were installed at the study area for real-time monitoring and analysis. It was found that amount and intensity of rainfall events strongly affect sediment yield from the study area. With net type sediment settling pond, it was expected that approximately 61% of sediment could be removed. The correlation between heavy metals and SS were analyzed in this study. $R^2$ values were 0.644, 0.876, 0.945, and 0.928 for Fe, Mn, Al, and Si, respectively. This results indicate that heavy metals also could be removed with net type sediment settling pond. As shown in this study, the sediment settling pond will be an efficient sediment reduction facility at highland agricultural areas. For maximum reduction efficiencies of sediment and other pollutants at agricultural fields, simplified sediment settling pond should be designed and implemented.

• 한국농공학회논문집
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• 제54권1호
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• pp.99-108
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• 2012

Soil erosion and sediment from agricultural farmland has caused various negative impacts on environment in recent years. The effect of rice straw mat on soil erosion has been investigated by many researchers these days. In this study, the SWAT model was applied to Hongcheon watershed to evaluate SWAT flow and sediment, and the effect of rice straw mat on sediment yield at watershed outlet was evaluated. The Nash-Sutcliffe model efficiency (NSE) and coefficient of determination ($R^2$) values for flow simulation (calibration period) were 0.66 and 0.67, and the NSE values for sediment was 0.90. The calibrated parameters were used to analyze the reduction of sediment yield in the farmland with rice straw mat. Average daily sediment yield without rice straw mat was 49.8 ton/day and sediment yield with rice straw mat was 25.5 ton/day, and the reduction rate was 38.7 %. Also, average daily sediment yield with/without rice straw mat were 97.5 ton/day and 190.7 ton/day during the rainy season (Jun. 2008 - Aug. 2009), with the reduction rate 46.3 %.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2014년도 추계학술대회
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• pp.87-88
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• 2014

The Coastal sediment is highly contaminated due to ship transportation, industries discharges and urban sources. Various contaminants release into seawater and settle in marine sediment and it significantly affect marine eco system. In the present study evaluated the optimization of slow release biostimulant ball (BSB) in coastal sediment in busan. The effective variables like BSB size, distance and month variables on VS reduction was determined by using Response surface methodology(RSM). The analysis of variance (ANOVA) and coefficient determination (R2) of VS was 0.9369 and maximum reduction of VS was obtained in 3cm ball size and 5.5cm distance and 4 month interval time. This result revealed that the BSB in effective VS reduction in coastal sediment.

• 한국농공학회논문집
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• 제54권2호
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• pp.27-35
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• 2012

Various Best Management Practices (BMPs) have been suggested to reduce Nonpoint source pollutant loads from agricultural fields. However, very little research regarding water quality improvement with sediment trap has been performed in Korea. Thus, effects of sediment trap were investigated in this study. Three sediment traps were installed at the edge of six plots and flow and water quality of inflow and outflow were monitored and analyzed. It was found that approximately 64.1 % of flow reduction was observed. In addition, pollutant concentration of outflow was reduced by 39.0 % for $BOD_5$. For SS, $COD_{Mn}$, DOC, T-N, T-P, approximately 62.1 %, 43.4 %, 43.5 %, 40.0 %, and 41.2 % reduction were observed, respectively. Over 80 % and 90 % of pollutant loads were reduced from sediment trap #2 and #3 because of less outflow from plots covered with rice straw/straw mat. In case of intensive rainfall events occurred from July 26~29, 2011, over 60 % of pollutant and 88.9 % of sediment reduction were observed from sediment trap #3. As shown in this study, small sediment traps could play important roles in reducing pollutant loads from agricultural fields. If proper management practices, such as rice straw/straw mat, are used to protect surface from rainfall impacts and rill formation, much pollutant reduction could be expected.

• 한국방재학회 논문집
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• 제11권3호
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• pp.183-189
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• 2011

본 연구에서는 저수지내 퇴사저감을 위하여 댐 상류에 저사댐을 설치하여 퇴적토를 포착하는 방법의 적합성을 검토하기 위해 국내 10개 다목적댐 유역을 대상으로 저사댐을 설치할 경우의 퇴사 저감효과에 대하여 분석하였다. 총 27개 설치지점의 퇴사 저감효과를 분석한 결과, 연구대상 다목적 댐 중 대청댐유역의 본류인 금강 지점의 저사댐 설치시 퇴사 저감효과가 가장 큰 것으로 판단되었으며 저사댐 설치에 따른 수명연장효과는 미설치시 수명보다 약 60%가 연장되는 것으로 판단되었다. 또한 저사댐 설치로 인한 퇴사 저감률에 영향을 미치는 인자를 알아보기 위하여 회귀분석을 실시한 결과 유역면적비가 가장 큰 영향을 미치는 것으로 판단되었으며 유역면적비에 대한 회귀식을 도출 할 수 있었다. 본 연구결과를 통해 국내 저사댐 도입시 기대 퇴사저감 효과 산정이나 설치위치 검토를 위한 기초자료 활용될 수 있을 것으로 판단된다.

• 한국수자원학회논문집
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• 제51권1호
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• pp.61-70
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• 2018

본 연구에서는 댐의 효율적인 계획 및 운영을 위해 댐 저수지의 최적 퇴사위 결정 방법에 대해 고찰하였다. 현재 우리나라는 안전한 설계에 의거하여 댐 저수지 사수위 내의 퇴사위 결정 방법은 비교적 높게 산정되는 수평퇴사법을 주로 적용하고 있지만, 댐 저수지의 퇴사위는 정확하게 계획되어야 하며, 이는 댐 생애주기 평가 차원에서도 중요한 요소이다. 댐 저수지의 퇴사위 결정을 위해 대표적인 방법으로는 RMA-2와 연계된 SED-2D의 모형에 의한 방법, 수평퇴사법, 면적증분법(area increment method), 경험적면적감소법(empirical area reduction method)이 있다. 본 연구에서는 최적 퇴사위 결정을 위해 이를 산정하여 2007년 기준 실측 퇴사위와 비교하였다. 또한, 현재 및 미래 퇴사위를 예측하여 각 방법별로 경향과 추이를 분석하였다. 실측 퇴사위와 산정된 퇴사위를 비교한 결과, 경험적면적감소법이 실측값과 가장 근사하게 산정된 것을 확인할 수 있었으며, 현재 및 미래의 퇴사위는 전반적으로 과거 퇴사위의 경향과 추이를 따라가는 것으로 확인되었다. 따라서, 본 연구의 결과를 토대로 보면 경험적 면적감소법의 이용이 적절할 것으로 판단되고, 모형에 의해 분석 결과의 타당성을 검정하는 것이 합리적이라 생각된다.

• 한국물환경학회지
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• 제32권1호
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• pp.108-114
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• 2016

Sediment-laden water leads to water quality degradation in streams; therefore, best management practices must be implemented in the source area to control nonpoint source pollution. Field monitoring was implemented to measure precipitation, direct runoff, and sediment concentrations at a control plot and straw-applied plot to examine the effect on sediment reduction in this study. A hydrology model, which employs Curve Number (CN) to estimate direct runoff and the Universal Soil Loss Equation to estimate soil loss, was selected. Twenty-five storm events from October 2010 to July 2012 were observed at the control plot, and 14 storm events from April 2011 to July 2011 at the straw-applied plot. CN was calibrated for direct runoff, and the Nash-Sutcliffe efficiency and coefficient of determination were 0.66 and 0.68 at the control plot. Direct runoff at the straw-applied plot was calibrated using the percentage direct runoff reduction. The estimated reduction in sediment load by direct runoff reduction calibration alone was acceptable. Therefore, direct runoff-sediment load behaviors in a hydrology model should be considered to estimate sediment load and the reduction thereof.

• 한국관개배수논문집
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• 제21권1호
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• pp.99-108
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• 2014

This study investigated the effects of NPS(non point source) pollution reduction of sediment traps through field experiments. Various sizes of 4 sediment traps were applied in a upland field located in Gunwi and assessed the infiltration and storage effects as well as NPS pollution reduction effects of this technique. The characteristics of deposited soil in the sediment traps were also analyzed including distribution of particle size, soil texture, and chemical properties. The results showed that slightly different composition of soil particle size from each sediment trap with high proportion of 0.15mm and 0.25mm ranges of soil particle diameters, while the loamy sand is the main types of deposited soils in the sediment traps. Decreased NPS pollution were observed from the water quality analysis of the samples taken from the sediment traps. Further research need to be proceeded continuously to improve this technique in order to utilize on upland fields for management of agricultural NPS pollutions.