• 한국농공학회지
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• 제45권3호
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• pp.94-102
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• 2003

A hydrologic and water quality monitoring network were established in the Balkan-reservoir watershed, which has 29.79 $km^2$ in size, to analyze the characteristics of pollutant loading from an agricultural small watershed. Soil type, land use, hydrologic soil group, population and livestock were also surveyed to make clear the pollutant sources and to calculate the pollutant loadings by the unit loading factor method which was proposed by the Ministry of Environment. From the 5-year hydrologic monitoring results, sub-watersheds located in the upstream of the reservoirs showed higher average runoff ratio. The calculated daily pollutant loadings by the unit loading factor method from HP#2 sub-watershed in the downstream of Balkan reservoir, were much greater than observed.

• 대한토목학회논문집
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• 제11권2호
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• pp.27-37
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• 1991

음부력을 갖는 유체가 소규모 저수지로 유입되어 일어나는 밀도류의 거동 및 순환이 차원해석과 수리실험을 이용하여 해석된다. 무차원침강점 및 밀도류전면속도, 밀도류전면이동거리, 머리 뒤의 밀도층내회석 등은 유입밀도후르드수, Fre의 영향을 받으며 밀도층의 두께, 흐름양상 및 저수지내 밀도의 변화는 밀도류전면이 하류단에 도달하여 반사되기 전과 후의 양상이 현저하게 다르다. 밀도층의 두께는 전자의 경우에는 Fre, 후자의 경우는 시간과 Fre의 영향을 받으며 이들은 지수식으로 표현할 수 있다.

• 한국수자원학회논문집
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• 제33권1호
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• pp.15-30
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• 2000

본 연구는 소규모 저수지의 위험도와 초기저수지 수위와의 관계를 설정하기 위하여 신뢰도 분석기법을 적용하였다. 저수지의 안전성을 평가하기 위해서는 변수들의 불확실성을 파악하여야 하며 기능 수행함수를 설정하여야 한다. 저수지의 위험도를 산정하는 절차는 우선 월류에 대한 기능수행함수의 위험도 기준을 설정한 후 변수들의 불확실성을 파악하고 적정한 신뢰도 분석기법에 의하여 위험도를 산정하게 된다. 적용된 신뢰도 분석기법은 MCS(Monte Carly simulation) 법과 MVFOSM (mean value first order second momet) 법이며 이를 이용하여 저수지의 위험도를 산정하였다. 이에 따라 설계 재현기간에 따른 위험도-초기 저수지 수위의 관계를 설정하였으며 이는 저수지의 운용에 유용하게 사용될 것으로 생각된다.

• 한국농공학회논문집
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• 제52권6호
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• pp.63-73
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• 2010

This study is to develop a downstream flood damage prediction model for efficient confrontation in case of extreme and flash flood by future probable small agricultural dam break situation. For a Changri reservoir (0.419 million $m^3$) located in Yongin city of Gyeonggi province, a dam break scenario was prepared. With the probable maximum flood (PMF) condition calculated from the probable maximum precipitation (PMP), the flood condition by dam break was generated by using the HEC-HMS (Hydrologic Engineering Center - Hydrologic Modeling System) model. The flood propagation to the 1.12 km section of Hwagok downstream was simulated using HEC-RAS (Hydrologic Engineering Center - River Analysis System) model. The flood damaged areas were generated by overtopping from the levees and the boundaries were extracted for flood damage prediction, and the degree of flood damage was evaluated using IDEM (Inundation Damage Estimation Method) by modifying MD-FDA (Multi-Dimensional Flood Damage Analysis) and regression analysis simple method. The result of flood analysis by dam-break was predicted to occurred flood depth of 0.4m in interior floodplain by overtopping under PMF scenario, and maximum flood depth was predicted up to 1.1 m. Moreover, for the downstream of the Changri reservoir, the total amount of the maximum flood damage by dam-break was calculated nearly 1.2 billion won by IDEM.

• 한국농공학회논문집
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• 제52권1호
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• pp.1-11
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• 2010

Generation and transportation of runoff and pollutant loads within watershed generated eutrophication at Daecheong reservoir. To improve water quality at Daecheong reservoir, the best management practices should be developed and applied at upper watersheds for water quality improvement at downstream areas. In this study, two small watersheds of upper Daecheong reservoir were selected. The Long-Term Hydrologic Impact Assessment (L-THIA) model has been widely used for the estimation of the direct runoff worldwide. To apply the L-THIA ArcView GIS model was evaluated for direct runoff and water quality estimation at small watershed. And the Web-based Hydrograph Analysis Tool (WHAT) was used for direct runoff separating from total flow. As a result, the $R^2$ (Coefficient of determination) value and Nash-Sutcliffe coefficient value for direct runoff comparison at An-nae watershed were 0.81 and 0.71, respectively. And the $R^2$ value and Nash-Sutcliffe coefficient value at Wol-oe were 0.95 and 0.93. The $R^2$ value of BOD, TOC, T-N and T-P at An-nae watershed were BOD 0.94, TOC 0.81, T-N 0.94 and T-P 0.89. And the $R^2$ value of BOD, TOC, T-N and T-P at Wol-oe watershed were BOD 0.80, TOC 0.93, T-N 0.86 and T-P 0.65. The result that estimated pollutant loadings using the L-THIA ArcView GIS model reflected well the measured pollutant loadings except for T-P in Wol-oe watershed. With L-THIA ArcView GIS model, the direct runoff and non-point pollutant (NPS) loadings in the watershed could be analyzed through simple input data such as daily rainfall, land uses, and hydrologic soil group.

• 농촌계획
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• 제9권2호
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• pp.1-6
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• 2003

This study was performed to investigate the degree of pollution of sediments of stream and reservoir in rural area. A series of field investigations were carried out for Kyongki-do area and chemical analysis were performed for sediment samples. It was found that some samples were heavily polluted with phenol and TPH and gave off a malodor. Soil Pollution Scores(SPSs) was determined for sediment samples. Some samples were classified to Soil Pollution Class(SPC) 2 and 3. For recycling and disposal of dredged sediments from stream and reservoirs, these polluted sediments should be carefully considered. In the environmental improvement operations of rural area, the degree of pollution of sediments of stream and reservoir are carefully investigated and suitable counterplan must be established.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 12th Asian Congress of Fluid Mechanics
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• pp.33.2-33.2
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• 2008

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권5호
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• pp.651-659
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• 2018

A multi-level overtopping wave energy converter was designed according to the large tidal range and small wave heights in China. It consists of two reservoirs with sloping walls at different levels. The reservoirs share a common outflow duct and a low-head axial turbine. The experimental study was carried out in a laboratory wave-flume to investigate the overtopping performance of the device. The depth-gauges were used to measure the variation of the water level in the reservoirs. The data was processed to derive the time-averaged overtopping discharges. It was found that the lower reservoir can store wave waters at the low water level and break the waves which try to climb up to the upper reservoir. The upper sloping angle and the opening width of the lower reservoir both have significant effects on the overtopping discharges, which can provide more information to the design and optimization of this type of device.

• 한국농공학회논문집
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• 제51권5호
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• pp.35-49
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• 2009

This study proposes a method to evaluate agricultural reservoirs drought by modifying SWSI (Surface Water Supply Index). The method was applied to Geum river basin and the results were represented as spatially distributed information. The SWSI evaluates hydrological drought of watershed unit by selectively applying one or all of the components of snowpack, precipitation, streamflow and reservoir storage. South Korea has 22 % of agricultural area, and rice paddy covers 64 % among them. Usually paddy fields scattered along stream are irrigated by so many small agricultural reservoirs. It is difficult to evaluate agriculture drought by the little information and large number of agricultural reservoirs. In this study, seven agricultural reservoirs over 10 million ton storage capacity were selected in Geum river basin, and the SWSI was evaluated for both upstream and downstream of the reservoirs using 16 years data (1991-2006). Using the results, multiple regression analyses with precipitation and reservoir storage as variables were conducted and the equations were applied to other watersheds. The spatial results by applying regression equations showed that the severe and moderate drought conditions of July and September in 1994, June in 1995, and May in 2001 were well expressed by the watershed unit.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2000년도 정기총회 및 봄 학술발표회
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• pp.251-254
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• 2000

In this study, we investigated vertical distribution and seasonal changes of phytophlankton community in the Hae-Dong Reservoir from March 1999 to Feburary 2000. This reservoir is relativly small (surface area, 2.7 $km^2$) and is the source of drinking water supply to the eastern part of Pusan City. Samples were collected at 2 sites (1, 3, and 6 m; site 1, in front of the dam; site 2, inlet). The dominant group was Bacillriophyceae at both sites (over 63%), and other groups exhibited seasonal changes (high cyanobacterial density in summer; green algal communities in winter). Chrysophyceae and Dinophyceae were maintained lower level during the study period. Along the water depth, all classess of phytoplankton did not show distintive vertical distribution at both sites except during the blue-green algal bloom in the middle of July and late September. The phytoplankton community dynamics in the Hoe-Dong Reservoir was strongly affected by the hydrological factors such as concentrated precipitation and short retention time.