• Journal of Wetlands Research
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• v.9 no.3
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• pp.51-61
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• 2007

In natural river, river-bed change is greatly influenced by the various factors such as river improvement, change of watershed land use, construction of dam and reservoir, gravel mining, and so on. The knowledge about river-bed change in the river is essential in the river modification, wetlands plan, and maintaining stable alluvial rivers. In this study, river-bed change in the future was predicted by investigating river channel characteristics which play dominant role in the formation of channel and based on the numerical model through river survey and the grain size analysis. The Proposed investigation and model was applied to the Geum river and the Miho stream which have been experienced river degradation due to river aggregate dredging and now seams to be stable. The result of potential river-bed change which was estimated by investigating channel characteristic including slope of channel, friction velocity, and so on is similar to that which was estimated based on the numerical model. It was found that the Geum river and the Miho stream will be stable. In the future, if considering the characteristics of river channel which is estimated by the river-bed scour, sediment, and so on, it is possible that river improvement and wetland restoration plan are established stably and naturally.

• Journal of Environmental Science International
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• v.19 no.1
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• pp.39-45
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• 2010

When the Juam multipurpose dam which is connected with existing large water supply facilities is finished, water environment is changed from stream to lake. The changed quality of water should be examined. In this study, the result of water quality forecasting is analysed and an effective management plan of water quality is presented. Tn this study, the WASPS model that is a dynamic water quality simulation model was selected to forecast the water quality. This model forecasts movement of change of pollutants. For an application of the model, the subject areas were divided into seventeen sub-areas by considering change temperature depending measuring points and on depth of water. Meteorological data collected by the meteorological observatory and data about quality measured by the Korea Water Resources Development Corporation were used for an operation of the model. As a result of quality examination through quality data and estimated pollutant loading, the water quality environment criterion was grade II and the nutritive condition was measured as meso-graphic grade. In this study, an effective management was planned to improve water quality by reducing pollution load. According to the result of examination, when more than 30% of BOD was reduced it was recorded that the environment standard of water quality was improved to the second grade.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4447-4454
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• 2013

In October 2011, a commercialized 100kW class floating photovoltaic system positive plant was installed at Hapcheon dam a multi-purpose reservoir the first time ever in the nation. Floating photovoltaic system differs in water float, mooring device and underwater cable process from land photovoltaic system. As for land and building photovoltaic power generation equipments, many installation cases and skilled experiences are available, and thus installation is not difficult. However, commercial power generation floating photovoltaic system, which is attempted for the first time in the nation, requires to be designed and installed through a series of processes like technical review and verification of data by process in comparison with similar cases. The structure of floating photovoltaic system, an equipment for float photovoltaic module and other electrical equipment, is required to withstand weather environments like wind or typhoon etc and yet not affect water quality negatively, and for implementation of this system, construction efficiency and economy etc should be considered comprehensively. In this paper, the techniques of installing floating photovoltaic structure, mooring device, underwater cable, electrical equipment and remote monitoring control system are explained. The 100kW floating PV system is operating with 15% average capacity factor.

• Journal of Korea Water Resources Association
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• v.37 no.10
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• pp.799-812
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• 2004

Conjunctive use of surface and ground water has drawn much attention as a promising means to solve water shortage problems. Characterized by its maximum utilization of regional resources and environmental friendliness, conjunctive use is expected to contribute to the integrated water resources management in the coming era. This paper examines the applicability of the methodology for conjunctive use developed in the companion paper (this issue). The method consists of the entire process of conjunctive use, including site assessment using analytic hierarchy process, management scenario development based on drought analysis, and evaluation of benefits obtained. Sokcho City was chosen as the study area, and the application of derived operation scenarios for surface and subsurface reservoirs revealed that water of 4.9∼7.4 million cubic meters a year can be attainable additionally. The developed methodology enables one to devise management schemes and to quantify their effectiveness, which makes the method useful for water resources planners as well as practitioners.

• Journal of Korea Water Resources Association
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• v.52 no.spc2
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• pp.835-844
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• 2019

This study dealt with a systematic approach for sediment replenishment works which defines the artificial supply of coarse sediment to downstream river channels of dams. That is an increasing practice in Japanese, American and European rivers for the purpose of compensating sediment deficits downstream and rehabilitating geomorphological habitats below dams. We introduced five main objectives of the sediment replenishment, simply from construction of artificial spawning redds for anadromous fish to restoration of fluvial geomorphological process of river system. Then we suggested determination of sediment size distribution and quantity of coarse sediment as well as selecting an effective implementation method in corresponding to specific objectives and local restrictions in the basin, reservoir and river.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.560-560
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• 2015

우리나라 연평균 수자원 총량은 1,297억톤이고 이용가능한 수자원량은 58%(753억톤)이며, 이 중 바다로 유실되는 32%(420톤)를 제외하고 연간 26%(333억톤)을 이용하고 있다. 용도별로 보면 생활용수 75억톤, 공업용수 21억톤, 농업용수 159억톤 및 유지용수 78억톤 등으로 사용되며 농업용수가 약 48%로 가장 많은 양이 차지하고 있다. 농업용수는 국내 수자원 소비량 중 가장 많은 양을 차지하고 있으나, 주기적인 가뭄에 따른 용수 부족이 매년 심각한 문제로 대두되고 있는 실정이며, 이에 대한 대책으로 저수지 준설, 둑 높이기, 다단계 양수장 건설 등을 통한 저수량 확보 사업이 진행되고 있으나 준설 및 둑 높이기시 막대한 사업비와 양수장 조성 공간 부족 등으로 농업용수 확보에 어려움이 발생하고 있다. 국내에서는 수자원 개발 및 친수공간 조성을 목적으로 매년 1,000여건의 하천공사가 실시되고 있으며, 하천공사로 인해 가물막이의 설치 및 해체가 계속적으로 발생하고 있다. 하천공사시 가물막이 설치를 위해 중장비의 출입 반드시 필요하나 중장비 출입이 어려운 지역에서는 공사기간 지연 및 경제성 등의 문제로 어려움을 겪고 있는 실정이다. 이에, 본 연구에서는 휴대용 차수막의 구조개선을 통해 (1) 저수지 증고 및 하천 가물막이에 적합한 설계 및 설치 방법을 개발하고, (2) 수압 및 부유물질에 안전하도록 강도를 개선하였으며, (3) 내구성, 경제성, 유지관리성이 개선된 재이용이 가능한 휴대용 차수막을 개발하였다. 휴대용 차수막 개발로 인해 저수지 증고 및 하천 가물막이 뿐만 아니라 방재 및 레크레이션용도 등 다목적 활용이 높은 것으로 나타나 수자원 분야에 다수 적용될 것으로 기대된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.184-184
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• 2016

최근 기후변화로 인하여 과거에는 발생하지 않았던 기상재해의 발생이 빈번해지고 있으며 그 피해규모도 전 세계적으로 증가하고 있다. 그 중 가뭄은 용수공급에 가장 직접적으로 영향을 미치는 원인이다. 우리나라에서는 2010년 이후 지속적인 가뭄이 발생하고 있다. 특히 2015년 금강서해유역의 보령강우관측소에서 연강우량은 783.1 mm로 보령강우관측소의 연평균강우량 1,244.3 mm 대비 62.9%에 불과하였다. 특히 많은 강우량이 집중되는 8월 누적강우량은 30.2 mm(예년대비 7%), 9월 누적강우량은 13.3 ??(예년대비 6%)로 보령지역에서는 강우 부족에 의한 가뭄이 2015년 이후 현재에도 진행 중이다. 국토교통부는 보령지역에 2016년 봄까지 충분한 강우가 내리지 않는다면 보령댐의 용수공급이 불가능할 것으로 판단하여 금강에 위치한 백제보 하류와 보령댐 상류를 연결하는 보령댐 도수로를 계획하였다. 국내에서 용수공급을 위하여 도수로를 이용한 사례로는 안동-임하댐 연결 도수로와 임하댐과 영천댐을 연결한 영천도수로 등이 있으며 관련된 연구로는 도수로 운영 이후 댐의 가용 수자원량을 분석한 사례가 있다. 본 연구에서는 도수로를 통해 보령댐으로 공급된 수량이 보령댐의 생공용수 공급에 미치는 영향을 분석하고자 하였으며 분석을 위해 미 육군공병단에서 개발한 저수지 모의운영 소프트웨어인 HEC-ResSim을 이용하여 보령댐이 완공된 1998년부터 2015년까지 18년 동안 보령댐 저수지 모의운영을 실시하였다. 모의운영 조건으로는 도수로 운영조건 및 용수공급 조정기준을 고려하여 케이스별로 모의운영을 실시하였고 그 결과를 바탕으로 이상갈수 시 공급순위가 가장 높은 생공용수의 공급신뢰도를 이용하여 도수로 운영효과를 비교 분석하였다.

• Coupled systems mechanics
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• v.7 no.6
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• pp.649-668
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• 2018

In this paper, we present a numerical model for fluid-structure interaction between structure built of porous media and acoustic fluid, which provides both pore pressure inside porous media and hydrodynamic pressures and hydrodynamic forces exerted on the upstream face of the structure in an unified manner and simplifies fluid-structure interaction problems. The first original feature of the proposed model concerns the structure built of saturated porous medium whose response is obtained with coupled discrete beam lattice model, which is based on Voronoi cell representation with cohesive links as linear elastic Timoshenko beam finite elements. The motion of the pore fluid is governed by Darcy's law, and the coupling between the solid phase and the pore fluid is introduced in the model through Biot's porous media theory. The pore pressure field is discretized with CST (Constant Strain Triangle) finite elements, which coincide with Delaunay triangles. By exploiting Hammer quadrature rule for numerical integration on CST elements, and duality property between Voronoi diagram and Delaunay triangulation, the numerical implementation of the coupling results with an additional pore pressure degree of freedom placed at each node of a Timoshenko beam finite element. The second original point of the model concerns the motion of the outside fluid which is modeled with mixed displacement/pressure based formulation. The chosen finite element representations of the structure response and the outside fluid motion ensures for the structure and fluid finite elements to be connected directly at the common nodes at the fluid-structure interface, because they share both the displacement and the pressure degrees of freedom. Numerical simulations presented in this paper show an excellent agreement between the numerically obtained results and the analytical solutions.

• 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.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.64-64
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• 2023

황강댐은 임진강 상류 군사분계선으로부터 약 42km떨어진 위치에 존재하며 약 3~4억톤의 규모로 추정된다. 이에 우리나라는 약 7천만톤 규모의 군남홍수조절지를 건설하여 임진강 상류로부터 기인하는 홍수를 방어하고 황강댐의 무단방류에 대비하고 있다. 과거 2009년 9월 6일 임진강 상류 황강댐에서의 대규모 방류로 인해 경기도 연천군 일대에 홍수가 발생하여 이로 인한 인명 및 재산피해가 발생한 바 있으며, 2020년 8월 5일에는 장마전선으로 인한 폭우와 더불어 임진강 필승교 수위관측소의 수위가 급상승하면서 관측 이래 역대 최고수위가 발생하여 홍수경보가 발령되고 인근 주민이 대피하는 사례가 발생하였다. 또한, 2022년 6월 27일부터 발생한 장마전선 및 집중호우로 인해 임진강 필승교 수위관측소의 수위가 급상승하면서 홍수주의보가 발령되고 인근 주민이 대피하는 사례가 발생하였으며, 7월에는 비가 내리지 않는 상황에서 황강댐의 방류로 추정되는 유입량이 필승교 수위관측소와 군남홍수조절지에서 관측되었다. 이에 본 연구에서는 인공위성 영상에서 추출한 황강댐의 수위를 이용하여 수문모형과 저수지 운영 알고리즘을 구축하고 당시 발생한 홍수사례를 분석하여 황강댐의 운영방식을 추정하였다. 분석결과, 2020년 8월 5~7일 사이에 발생한 유입량의 경우 자체 유역 유입량은 전체 유입량대비 약 33%이나 북한 황강댐으로부터 추가로 방류된 양은 약 67%로 군남홍수조절지 유입량의 3/2 가량이 북한 황강댐의 방류량으로부터 발생된 것으로 보이며 2021년 6월에도 유사한 양상을 보였다. 하지만, 북한 황강댐의 운영방식이 용수공급을 위한 고수위 유지 운영방식에서 홍수기에 댐 월류 및 파괴를 방지하기 위한 사전방류를 수행하는 것으로 추정되었다.