• 한국습지학회지
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• 제16권2호
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• pp.221-233
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• 2014

유수에 의한 하천 유역과 하천의 토양의 침식, 유송, 퇴적 현상은 빈번하게 발생한다. 이러한 과도한 현상은 수공구조물의 안전위협, 홍수범람 등의 자연재해를 가중시킨다. 토양침식에 따른 토사재해를 방지하기 위해서는 가장 우선적으로 정확한 유사유출량을 예측할 필요가 있다. 이를 위해서는 유역특성에 적합한 모형의 선정, 관련인자의 정량적인 산출, 가용 수문자료의 확보는 매우 중요하다. 따라서, 본 연구의 목적은 실측자료를 확보하고 있는 설마천 시험유역의 강우량, 유출량, 유사량 자료를 이용하여 강우-유출거동에 따른 토양침식량과 유사유출량을 산정하는데 있다. 그리고 유사전달률 분석을 통하여 설마천 시험유역의 유사전달률을 제안하였다. 향후에는 타 유역에도 적용하여 다양한 조건에서의 토양침식량 및 유사유출량 산정방법의 정형화, 유역 특성별 유사전달률 산정 연구를 하고자 한다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2016년도 학술발표회
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• pp.196-196
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• 2016

Landslide dam failure presents as a severe natural disaster due to its adverse impact to people and property. If the landslide dams failed, the discharge of a huge volume of both water and sediment could result in a catastrophic flood in the downstream area. In most of previous studies, breaching process used to be considered as a constructed dam, rather than as a landslide dam. Their erosion rate was assumed to relate to discharge by a sediment transport equation. However, during surface erosion of landslide dam, the sediment transportation regime is greatly dependent on the slope surface and the sediment concentration in the flow. This study aims to accurately simulate the outflow hydrograph caused by landslide dam by overtopping through a 2D surface flow erosion/deposition model. The lateral erosion velocity in this model was presented as a function of the shear stress on the side wall. The simulated results were then compared and it was coherent with the results obtained from the experiments.

• 한국조경학회지
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• 제26권4호
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• pp.59-69
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• 1999

This study examines the existing theories related to detention basin and embodies the calculation process of sediment basin. It investigated the scale of sediment basin by actual measurement at Buju Mountain, Mokpo city which causes the environmental problems like erosion and outflow of sediment due to the excessive development, finds the problems of existing sediment basin by applying and analyzing the physical factors which affect the execution of sediment basin using GIS as the method establishing the scale of sediment basin embodied in this study and then suggests the oteimum scale. Comparing the surface area of the existing sediment basin and of the required one, all of the surface areas of the existing sediment basins were smaller than those of the required one. Therefore, it can be expected that the trap efficient of sediment will be declined. The required one. Therefore, it can be expected that the trap efficient of sediment will be declined. The required minimum depth was fully satisfied, but it is analyzed that the volume of sediment basin will affect the neighboring environment because it can not accomodate the inflow discharge volume except sediment basin C. It is consistent with the actual situation which causes a serious environmental problem due to the overflow of sediment basin during the heavy storm event except sediment basin C and also it verifies the validity of calculation process of establishing optimum sediment basin suggested in this study.

• 한국지반환경공학회 논문집
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• 제15권4호
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• pp.13-27
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• 2014

Catchments soil erosion, one of the most serious problems in the mountainous environment of the world, consists of a complex phenomenon involving the detachment of individual soil particles from the soil mass and their transport, storage and overland flow of rainfall, and infiltration. Sediment size distribution during erosion processes appear to depend on many factors such as rainfall characteristics, vegetation cover, hydraulic flow, soil properties and slope. This study involved laboratory flume experiments carried out under simulated rainfall in a 3.0 m long ${\times}$ 0.8 m wide ${\times}$ 0.7 m deep flume, set at $17^{\circ}$ slope. Five experimental cases, consisting of twelve experiments using three different sediments with two different rainfall conditions, are reported. The experiments consisted of detailed observations of particle size distribution of the out-flow sediment. Sediment water mixture out-flow hydrograph and sediment mass out-flow rate over time, moisture profiles at different points within the soil domain, and seepage outflow were also reported. Moisture profiles, seepage outflow, and movement of overland flow were clearly found to be controlled by water retention function and hydraulic function of the soil. The difference of grain size distribution of original soil bed and the out-flow sediment was found to be insignificant in the cases of uniform sediment used experiments. However, in the cases of non-uniform sediment used experiments the outflow sediment was found to be coarser than the original soil domain. The results indicated that the sediment transport mechanism is the combination of particle segregation, suspension/saltation and rolling along the travel distance.

• 한국방재학회 논문집
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• 제7권1호통권24호
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• pp.67-72
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• 2007

본 연구에서는 토사에 대한 질량보존의 법칙을 이용하여 자연유역 내 토양의 침식 및 퇴적 잠재능을 산정할 수 있는 모델을 개발하였다. 이 프로그램은 각 셀 별 토사에 대한 질량보존의 법칙을 적용하여 GIS환경하에서 구동 가능하도록 구성되어있으며 셀 별 토사발생량은 RUSLE 공식을 이용하여 산정하였다. 토양의 침식 및 퇴적 잠재능은 토사의 유출량과 유입량의 차에 의해 각 셀이 침식되거나 퇴적된다는 질량보존의 법칙을 이용하여 산정하였다. 질량보존의 법칙을 적용하기 위한 셀 별 토사유출량은 토사발생량과 토사전달률을 곱하여 산정하였으며 이 토사 유출량이 흐름방향 알고리즘에 의해 결정되는 하류 셀의 토사유입량이 된다. 본 연구에서 개발된 모델을 이용하여 국내 소유역에 대해 적용하였으며 그 결과를 실측치와 비교함으로써 모델을 검증하였다.

• 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.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.125-125
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• 2023

Estuarine dams are dams constructed in estuaries for reasons such as securing freshwater resources, controlling water levels, and hydroelectric power generation. These estuarine dams alter the flow of freshwater to the coastal ocean and the tidal properties of the estuaries which has implications for the estuaries' circulation and sediment transport. A previous study has analyzed the effect of estuarine dams on 1D (along-channel) circulation and sediment transport. However, the effect of estuarine dams on the transverse variability of along-channel and across-channel circulation and sediment transport has not been studied and is not known. In this study, a coupled hydrodynamic-sediment dynamic numerical model (COAWST) was used to analyze the transverse variability of along-channel and across-channel flow and sediment transport in estuaries with estuarine dams. The estuarine dam was found to change the 3D structure of circulation and sediment transport, and the result was found to depend on the estuarine type (i.e., strongly stratified (SS) or well-mixed (WM) estuary). The SS estuary had inflow in the channel and outflow over the shoals, consistent with estuarine circulation. Longer discharge interval reduced the estuarine circulation. The WM estuary had inflow over the shoals and outflow in the channel, consistent with tide-induced circulation. As the estuarine dam was located nearer to the estuary mouth, the tide-induced circulation was reduced and replaced with estuarine circulation. The lateral circualtion was the greatest in the tide-dominated estuaries. It was reduced and changed direction due to differential advection change as the dam was located nearer the mouth. Overall, the WM estuary transverse flow structure changed the most. Lateral sediment flux was important in all estuaries, particularly for transporting sediments to the tidal flats.

• 한국관개배수논문집
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• 제8권2호
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• pp.64-72
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• 2001

Sihwa dyke was constructed during the period from June, 1987 to January, 1994 and the sluice gates were opened to allow sea water intrusion and outflow to improve water quality of the lake since June, 1997. Bottom sediment samples from 29 stations were co

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.368-368
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• 2022

The Soil and Water Assessment Tool (SWAT) has been widely used to simulate the long-term hydrological conditions of a catchment. Two output variables, outflow and sediment yield have been widely investigated in the field of water resources management, especially in determining the conditions of ungauged subbasins. The presence of missing data in weather input data can cause poor representation of the climate conditions in a catchment especially for large or mountainous catchments. Therefore, in this study, a custom module was developed and evaluated to determine the efficiency of utilizing basic spatial interpolation methods in the estimation of weather input data. The module has been written in Python language and can be considered as a pre-processing module prior to using the SWAT model. The results of this study suggests that the utilization of the proposed pre-processing module can improve the simulation results for both outflow and sediment yield in a catchment, even in the presence of missing data.

• 한국환경과학회지
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• 제12권3호
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• pp.247-255
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• 2003

Forest management starts from forest road facility, which is designated as generation source of muddy water in mountain stream during initial stage of establishment. Therefore, this study reviewed the effect of suspended sediment generated in forest road surface on the muddy water in mountain stream with respect to marsh area of forest. As a result, characteristics of outflow of suspended sediment was understood, and it was judged that generation of suspended sediment due to establishment of forest road is diluted by mountain stream this charged from drainage area so as to have small effect on muddy water in total mountain stream.