• 한국환경과학회지
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• 제24권12호
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• pp.1617-1627
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• 2015

This study was carried out to investigate the characteristics of suspended solid concentration in small forest watershed, Hwacheon, Gangwondo. For five rainfall events from July 2013 to August 2013, rainfall, discharge, and suspended solid load has been measured. The results showed that the fist flush effect was observed for suspended solid in each rainfall event, sediment rating curve was obtained with $y=30.029x^{1.573}$ at rising limb and $y=12.902x^{1.8827}$ at falling limb, and EMC (event mean concentration) of suspended solid was calculated to 9.4 mg/L. EMC was compared to the values from the watershed that has various land use types and EMC from forest watershed was much lower that from the crop, paddy or low covered forest watershed.

• 한국수자원학회논문집
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• 제33권5호
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• pp.581-592
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• 2000

본 연구에서는 식생된 개수로에서의 난류 구조와 부유사 이동을 수치모의하였다. 난류폐합식으로는 $\textsc{k}-\;\varepsilon$ 난류모형을 사용하였다. 수치모의를 통해 평균유속, 난류강도, 레이놀즈 응력, 난류에너지 생성 및 소멸의 분포를 계산하였으며, 기존의 실험결과와 비교하였다. 식생에 의한 항력으로 인하여 평균유속이 전반적으로 감소되었으며, 이에 따라 난류강도와 레이놀즈 응력의 분포 역시 약화되었다. 침수식생의 경우, 식생높이보다 높은 구간에서는 전단에 의한 난류에너지 생성이 지배적이며, 식생높이 보다 낮은 구간에서는 후류에 의한 난류에너지 생성이 지배적임을 확인하였다. 또한 정수식생의 경우, 전채 수심에 걸쳐 후류에 의한 난류에너지 생성이 지배적으로 발생하였다. 대체적으로 수치모의에 의한 결과가 실험값과 유사한 양상을 보이는 것이 확인되었다. 수치모형으로부터 계산된 난류동점성계수 분포를 이용하여 부유사 보존방정식을 수치해석하였다. 식생된 개수로에서의 부유사 농도는 일반 개수로에 비해 전 수심에 걸쳐 균일하게 분포하였다. 또한 식생밀도가 증가할수록 부유사량은 감소하며, 동일한 식생밀도에 대해서는 입자의 크기가 작을수록 부유사량이 증가함을 확인하였다.

• 한국해양환경ㆍ에너지학회지
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• 제10권1호
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• pp.1-12
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• 2007

여자만 내의 봄철 퇴적물 공급원을 파악하기 위하여 만 입구(서수도: M-1, 조발수도: M-2)와 하천 유입구(벌교천: M-3, 동천, 이사천: M-4)에서 부유퇴적물의 유 출입량 변화를 관측하고, 만 내 표층 퇴적물 조성과의 상관성을 비교 검토하였다. 여자만에서 2조석 주기동안 단위 폭 당 부유퇴적물은 M-1(서수도)정점을 통하여 $133.88\;kg{\cdot}m^{-1}$ 유입되고, M-2(조발수도)정점을 통하여 $146.43\;kg{\cdot}m^{-1}$ 유출되며, M-3(벌교천) 정점을 통하여 $23.25\;kg{\cdot}m^{-1}$, M-4(동 이사천) 정점을 통하여 $4,312.31\;kg{\cdot}m^{-1}$ 유입된다. 여자만 내의 봄철 부유퇴적물 유입은 만 입구에서는 거의 없으며 북쪽의 동 이사천에서 주로 유입되고 있음을 알 수 있었다. 그리고 만 내의 표층퇴적물 조성이 건기 때 보다 우기 때가 더욱 조립하게 나타나는 것은 만내 퇴적물 주 공급원인 동 이사천에서 우기시 실트질 퇴적물이 다량 유입되는 것에 기인하는 것으로 생각된다.

• 물과 미래
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• 제23권1호
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• pp.119-127
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• 1990

점착성 부유사 농도분포는 해수유동과 물질 확산에 의해서 결정되며 지배방정식으로는 2차원 수심적분된 Reynolds운동방정식, 연속방정식과 Fick의 확산법칙에 근거를 둔 대류-확산방정식이 사용되었다. 해수유동과 점성퇴적물 확산인 두개의 모형은 유한차분법을 이용하였고 유동모형은 양해법, 확산모형은 다증법을 사용하여 부유사 이동의 현상을 파악하였다. 해수유동방정식의 적용시 이송항의 포함여부에 대해서 조사하였으며 물질확산 방정식에 대해서는 한계전단응력값의 변화가 부유사농도에 영향을 주는가에 대해서 비교하였다.

• 한국물환경학회지
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• 제39권4호
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• pp.329-342
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• 2023

Turbid water and suspended sediment (SS) load are having negative consequences such as water quality degradation and ecological damage, thus necessitating the establishment of management guidelines to reduce their impact. The present work investigates the spatio-temporal distribution of fish species and the effects of turbid water from 2011-2016 in the upper reaches of Soyang-Dam. The family Cyprinidae is the largest population in the study area, among which Zacco platypus and Zacco koreanus are the dominant species. The diversity of species is relatively abundant in the upper watershed, while the seasonal effect on the population distribution remains unclear. Using two main common components of the empirical orthogonal function (EOF) analysis, the distribution characteristics of 27 species at five survey sites are revealed. Zacco koreanus is found to be predominant at the upstream A-Naerincheon, while Zacco platypus and Rhinogobius brunneus are found to be predominant at the upstream B-Bukcheon. Disturbance of an aquatic ecosystem has a relatively greater impact in the downstream, as-compared to the upper area-the high proportion of forest area is decreased whereas that of agricultural and urbanized areas is increased. The patterns of representative species are changed according to the mid- to long-term effects of turbid water and SS. Accordingly, the significant correlation between the SS load and fish distribution EOF analysis indicates that it should be considered as a potential alternative that can overcome the limitations of impact assessment on turbid water to the Fish Assessment Index (FAI). A comprehensive study examining the long-term effects of SS load to the fish ecosystems with a systematic statistical analysis of sufficiently accumulated data at the national level is needed as future research.

• ALGAE
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• 제27권2호
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• pp.115-123
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• 2012

The establishment of algal spores plays an essential role in adult kelp distribution and abundance patterns. Sedimentation is a key variable regulating algal spore settlement and success, possibly controlling species-specific dominance $in$ $situ$. Laboratory experiments were used to determine spore attachment and survival rates of two Alaskan canopy-forming kelps, $Nereocystis$ $luetkeana$ (K. Mertens) Postels & Ruprecht and $Eualaria$ $fistulosa$ (Postels & Ruprecht) M. J. Wynne, to various types of sediment loading. Spore attachment for both species was significantly and similarly affected by three sediment treatments: suspended particles; settled sediment covering the substratum; and smothering of attached spores by settling sediment. Spore attachment decreased by approximately 90% at 420 mg sediment $L^{-1}$, the highest sediment load tested here, under all three treatments for both species. These results suggest that increases in sedimentation may constrain the success of the spore stages, but sediment does not seem to be a likely factor explaining species-specific distribution patterns. However, while sedimentation affected spores of both species similarly, timing of spore release in relation to times of maximum sediment load in the water might differ for different species, possibly explaining kelp species distribution patterns.

• Journal of Advanced Research in Ocean Engineering
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• 제2권3호
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• pp.99-111
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• 2016

Seabed affected by scouring, sedimentation, and siltation occurrences often cause exposure, which induces risks to existing structures or crude oil or gas pipeline buried subsea. In order to prevent possible risks, more economical structure installation methodology is proposed in this study by predicting and managing the risk. Also, the seabed does not only consist of sandy material, but clayey soil is also widespread, and the effect of undrained shear strength should be considered, and by cyclic environmental load, pore water pressure will occur in the seabed, which reduces shear strength and allows particles to move easily. Based on previous research regarding sedimentation or erosion, the average value of external environmental loads should be applied; for scouring, a 100-year period of environmental conditions should be applied. Also, sedimentation and erosion are mainly categorized by the bed load and suspended load; also, they are calculated as the sum of bed load and suspended load, which can be obtained from the movement of particles caused by sedimentation or erosion.

• 상하수도학회지
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• 제18권1호
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• pp.22-28
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• 2004

The fate and transport mechanism of pollutants which have affinities to particles, such as trace metals and some petroleum product based compounds, can be effectively explained by the movement of sediment. The sediment release from lands to adjacent water bodies due to rainfall events was investigated in an effort to predict the total suspended solids (TSS) concentrations in runoff. The contribution of sediment from land origin to the river TSS can be better understood by the relationship between TSS concentration and particle size in runoff. The sieve analysis was used to determine the particle size distribution and these results were incorporated into statistical models. The critical size of particles was set to $74{\mu}m$ which contributes to the river TSS concentration since fine particles (wash load) of the sediment in the runoff play the key role in constituting TSS in a water column of the river. Empirical relationships were developed to predict TSS in runoff from the percentage of the critical particle size and were proven statistically to be valid.

• 한국항만학회지
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• 제13권1호
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• pp.147-154
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• 1999

A Numerical model is developed in order to predict cross-shore beach profile change. In this model it is assumed that sediment transport is generated by waves(bed load transport suspended load transport) and undertow which is defined as offshore directional steady flow in the surf zone. In addition wave tank experiments which reproduce storm-surge were performed. By comparing resulting profile of calculation with experiments, the applicability of this method is verified.

• 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.