• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.426-432
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• 2010

A level-set finite-element method is employed to investigate the free surface flow of two conceptual fish passage designs. While one design has a right-angled entrance from the reservoir to the fish passage chute, the other has a curved-shaped entrance. The numerical results are validated with hydraulic experiments through comparison of the free surface location and the pressure distribution in the spillway. It is observed that the right-angled design yields a curved free surface and pressure distribution in the vicinity of the entrance due to large strains, whereas the curved-shaped design yields a smooth flow transition with small strains. The subatmospheirc pressure distributions near the spillway ogee crest for both designs exhibit similar flow patterns. It is concluded that the curved-shaped design is more favorable for fish passage because of the feature of a smooth flow transition with small strains.

• Journal of Korea Water Resources Association
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• v.39 no.7 s.168
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• pp.627-636
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• 2006

This study estimates adequate discharge to meet the specified target water quality concentration using the pollutant load of the Geum river basin given in TMDL (Total Maximum Daily Load) report. During the 1st phase, BOD is chosen as a target water quality constituent under regulation of the Ministry of Environment in Korea. BOD, TN, and TP loads estimated based on the TMDL and provincial zones were re-distributed for 10 major tributaries, and the remaining areas along the main river are classified as 15 incremental flow areas. Water quality modeling was conducted using Qual2E for the low flow period of a year (i.e. $March{\sim}April$). The results of the model simulation showed that about 30 cms from the Daechung dam would be sufficient to satisfy the target water quality in the Geum river downstream of the Daechung multipurpose Dam.

• Journal of Wetlands Research
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• v.9 no.2
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• pp.71-84
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• 2007

Masan Bay is a representative semi-closed bay acted as a sedimentation reservoir with a slow current velocity and a poor water circulation in Korea. The pollutants from terrestrial sources into the Masan Bay have apparently environmental pollution problems, such as eutrophication, red tied, and hypoxia. In this study, An ecological modeling work was performed to estimate the material circulation including the growth of bivalve in ecosystem. Furthermore, the effect of water purification was calculated by filter feeding bivalve to particulate organic matter just like COD and phytoplankton. And Water quality management strategy by bio-purification of bivalve is derived through selection of location, quantification of bivalve aquaculture farm. The results showed that the optimum location for bivalve farming is where phytoplankton accumulation by physical processes is maximized and the optimum density and area of bivalve are 35 individuals $m^{-3}$ and ca. 500 hectare, respectively. When assuming conditions for the optimum growth of bivalve, COD could decrease by up to 18% even without other reduction of pollution loads.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.3
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• pp.221-231
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• 1993

WASP4. an estuarine or lake water quality model, wat applied to simulate future water qualities at alternative withdrawal sites for capital areas. Simulated water quality constituents were Chlorophyll a, nitrogen cycles, Phosphorus, BOD End DO. A Water budget analysis Using the monthly records of reservoir inflows and outflows between 1986 and 1990 was made to determine seasonally-averaged flowrates at model boundaries. Estimated flowrates were used. together with the seasonal water quality inputs simulated by the QUAL2E model, for the simulation of future water qualities. Sensitivities to the future pollutant inputs and possible future withdrawal alternatives were also analyzed. From simulations or future water qualities it is found that among the candidate withdrawal sites. the one located at the downstream end of the North Han River has the best future water quality in all quality constituents and the one at the downstream end of the South Han River has the worst Possible future withdrawal from the North Han River brings a slight increase or pollutant concentrations at existing withdrawal sites. but the aggravation of water quality is not significant.

• Journal of the Korean GEO-environmental Society
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• v.7 no.6
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• pp.57-65
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• 2006

In this study, WASP6 was used to predict the water quality of the reservoir and the lake. This can help the managers make the right choice of water quality policy. The results through studying are below. Raw pollutant load caused by the tourists in pollutant load of the study area takes 91.66% and 92.75% in total amount T-N, T-P. It showed high value when compared to raw pollutant load by land and stock farm and it seems that the main contamination is the population of tourists. From the result of the prediction model, BOD will increase about 1.5 times, T-N and T-P will be 1.5 times in 2012. It means that some counter plan is needed to reduce pollutant load. Enviroment grade of Suokjeong reserver is in I~II grade which is in good condition comparatively. However, the water contamination will be in poor as the year passes. when considering T-N T-P, which are the nutrients to control eutrophication, the concentrated administration about contamination sources is in urgent.

• Journal of Korea Water Resources Association
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• v.46 no.4
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• pp.373-387
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• 2013

For the efficient operation and management of the water resources system, coordinated operation of weirs and reservoirs is required. A simulation based, and an optimization based approaches are available to deal with the operation and management problems. The simulation based approach does not guarantee an optimal solution, and the optimization based approach is not so flexible to consider, complex, nonlinear problems we will face when trying to allocate water to different uses, various demand sectors in a basin. Hence, it is important to develop a model that would compensate for the weak points in both models. We will compare and contrast intrinsic and extrinsic properties of two modeling approaches, addressing issues related to setting system operation and control rules that would lead us to more efficient use of water in the basin. As a result, we propose to use CoWMOM(Coordinated weirs and multi-reservoir operating model), a "simulation based" optimization model for a simple simulation of the past periods, and for the real-time simulation process considering uncertain inflow.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.4
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• pp.395-403
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• 2000

It is so sensitive that the matter of compensation for private possessions caused in the course of public construction planning is very important. Especially, more logical planning is necessary when the dam be constructed, because it is mainly controlled by the surface of water, and if that planning is made public, artificial change is occurred in land use in that area for the purpose of rising the compensation. In this study, the plan for the application of aerial photo based ortho image was drew up for solving these problems and for the rational, rapid compensation. Ortho image was made by aerial photo, used as reading material for the change in land use. The modeling of drainage basin, came under the planning surface of water, and the 3D simulation were performed for the scene analysis, the change understanding in land use for a lot number in a certain period by overlapping the digital image, the digital land registration map, and the digital topography map as well as the analysis of the admitted land followed by the height of reservoir water.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.321-326
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• 2012

장기유출모형을 이용하여 농업용저수지 유입량을 예측하고 농업용수 필요수량 및 홍수기 저수지 홍수조절을 통한 방류량 데이터를 이용하여 장기간에 대한 농업용저수지 저수율을 계산하였다. 계산결과와 실측 저수율 데이터의 비교 검증을 통하여 모형의 적용성을 평가하였다. 대상유역은 담양댐 지점이며 유역면적은 $47.2km^2$ 이며 주 하천 연장은 12.0km 이다. 담양댐은 저수용량에 비하여 유역면적이 작기 때문에 댐 계획 당시 순창군 구림면에 유역면적 $18.4km^2$ 인 2개의 보를 축조하여 유역변경방식으로 간접유역 유출량을 비관개기 및 홍수시에 도수하며 최대 도수량은 $10m^3/s$이다. 장기유출모의는 한국수자원공사(2001)에서 수행한 전역최적화기법인 콤플렉스 혼합진화기법을 통하여 추정된 나주지점의 모형보정 성과를 활용하였으며 모의기간은 1981-2010년(30년)이다. 장기유출모의 결과 담양댐 유역의 평균 유출율은 67% 인 것으로 분석되었다. 농업용수 필요수량은 한국농촌공사에서 산정한 연도별 필요수량 산정결과를 이용하여 실측 농업용수 월별 방류량 자료를 기준으로 관개개간인 4월 21일-9월 20일(163일)동안 월별로 분배하여 적용하였다. 홍수조절은 기존 댐 상시만수위, 홍수기제한수위 데이터를 근거로 운영하였다. 일별저수지 운영모형은 미공병단의 HEC-5 모형을 이용하였으며 한국농어촌공사 농촌용수종합 정보시스템(RAMIS)의 댐 일별 저수율 현황과 기존저수지 일별 저수지 모의운영결과를 비교 검증하였다. 모형수행결과 실측저수율과 모형수행결과의 상관계수는 0.93 인 것으로 분석되었다. 연구결과, 장기유출모의 결과와 연계하여 농업용수, 하천유지용수, 홍수조절을 고려한 저수지 운영을 통하여 비교적 정확하게 농업용저수지 저수율을 예측할 수 있을 것으로 판단된다. 본 연구성과를 바탕으로 농업용저수지의 장기적인 용수수급현황을 예측하여 효율적인 용수공급계획을 수립할 수 있을 것으로 기대된다.

• Journal of Korea Water Resources Association
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• v.32 no.6
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• pp.711-720
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• 1999

In this study, a various rainfall-runoff modelling approaches have been applied to the runoff response of flood hydrograph in three experimental watershed of the western part of korea. Mathematical models of runoff response also have been studied including linear system theory based on modeling techniques. Eight models were operated at the five water level gauging stations and the parameters of each model were computed by the Rosenbrock's hill climbing method to minimize the objective function. For the parameter verification of the models, a different complex rainfall-runoff event was selected in the same of the three river basins and derived IUH of the each model could be calibrated. Furthermore multiple regressions of the logarithmic transformation method between model parameters and catchment characteristics were studied in the selected five station.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.5
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• pp.323-331
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• 2019

In this study, a computational model approach for the modeling of hydrodynamic pressures acting on radial gates during strong earthquakes is proposed. The use of the dynamic layering method with the Arbitrary Lagrangian Eulerian (ALE) algorithm and the SIMPLE method for simulating free reservoir surface flow in addition to moving boundary interfaces between the fluid domain and a structure due to earthquake excitation are suggested. The verification and validation of the proposed approach are realized by comparisons performed using the renowned formulation derived by the experimental results for vertical and inclined dam surfaces subjected to earthquake excitation. A parameter study for the truncated lengths of the two-dimensional fluid domain demonstrates that twice the water level leads to efficient and converged computational results. Finally, numerical simulations for large radial gates with different curvatures subjected to two strong earthquakes are successfully performed using the suggested computational model.