• 한국지형학회지
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• 제28권2호
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• pp.1-13
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• 2021

It is very important to secure sufficient river maintenance flow for the ecosystem, since the ecosystem in the downstream section of the dam is greatly affected by the stream maintenance flow from the dam. However, the amount of discharge from the Seomjingang Dam is decreasing year by year, this study estimated the ecological flow required for the downstream section of the Seomjingang Dam, which is known as the habitat of the endangered Acheilognathus somjinensis, in order to secure the river flow of the Seomjingang Dam. For this purpose, the proper discharge was calculated using the PHABSIM model, which is a hydrological survey and physical habitat simulation method, and the proper discharge of other fish species were also comprehensively reviewed. As a result of this study, the current river maintenance flow at the Seomjingang Dam partially satisfies the ecological maintenance flow including the Acheilognathus somjinensis in the downstream section of the Seomjingang Dam. However, this is recognized as the minimum discharge to maintain the ecology in the downstream section of the Seomjingang Dam, and it would be more desirable to secure larger river maintenance flow than this. This study can contribute the determination of the river maintenance flow of the Seomjingang Dam by proposing the river maintenance flow considering the fish habitat environment in the river.

• 물과 미래
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• 제24권1호
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• pp.83-92
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• 1991

본 연구는 금강유역의 주요수위표 지점에서 하천유지유량을 산정하는데 그 목적이 있다. 하천유지 유량을 산정하는 방법에는 수요적인 측면과 공급적인 측면 두가지로 분류할 수 있다. 본 논문에서 하천유지유량의 개념은 평균갈수량과 환경보존유량중 큰 값으로 결정하였다. 하천유지유량의 산정에서 대청댐 상류지역은 평균갈수량으로, 대청댐 하류지역은 평균갈수량과 QUAL2E 모형으로 산정된 수질보전유량값 중 큰 값을 하천유지유량으로 결정하였다. 그 결과 대청댐 하류인 공주와 규암지점 모두 평균갈수량 값이 크게 나타났으며 그 값은 공주지점에서 33.82$m^3$/sec, 규암 지점은 51.51$m^3$/sec 이였다. 그러므로 금강유역의 하천유지유량의 산정은 평균갈수량으로 결정하는것이 타당하다고 판단되었다.

• 한국물환경학회지
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• 제31권1호
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• pp.35-41
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• 2015

This study focuses on whether a physical habitat model, River2D, is useful to assess and design stream restoration. To achieve the aim, the habitat suitability for Zacco Platypus was analyzed using River2D at midstream of the Anyang-Cheon through modifying the low flow channel and changing the flow discharge. The River2D simulation results show that the inhabited environment for Zacco Platypus is improved by increasing the sinuosity of the low flow channel, and vice versa. Also the inhabited environment for Zacco Platypus gets worse when there is no additional flow for maintenance water supply at the stream flowing through cities. In this respect, the physical habitat simulation study based on the River2D model is useful because it provides a practical guidance in designing stream restoration.

• 환경영향평가
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• 제16권3호
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• pp.187-194
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• 2007

It started road constructions around river in 1990s. These maintenances concentrate on city river. Because river lives no living things and men don't come near there. But in spite of these river environment go to rack, river maintenances still keep on using preexistence method since 1990s. Only a part of city river environment maintenances consider environmental ability of passive river, river maintenance of a purpose of flood control still don't consider in the concrete. Because propulsion device that consider environment ability of passive river and possible application techniques don't complete. In accordance, A natural river maintenance needs absolutly a series of river projects. Because a natural river maintenance prevents a damage of environment ability. This study is to assume the flood really happened and to carry out the flood damage simulation needed in overflow simulation about the inundated zone. Also, This study examine unstable part about the hydraulic characteristic as velocities, stream power, shear, hydraulic depth, flow area in basin. And this study applied the HEC-RAS(river analysis system) model to predict flood overflow in youngsan river basin. Project flood is used the return period 100 year and inputed data that was calculated in intensity figures of illumination.

• 한국농공학회논문집
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• 제61권5호
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• pp.33-47
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• 2019

The environmental ecological flow (EEF) of stream or river will be designated according to the enforcement of the Water Environment Preservation Act. Previous researches by Ministry of Environment have proposed agricultural reservoirs as alternative resources to secure river flow where multi-purpose dam does not exist. However, agricultural reservoirs are constructed for the supply of agricultural water, and in fact, there is not a sufficient amount of water to be supplied to rivers as EEF. Therefore, this study examines the economic feasibility of securing EEF through the remodeling or construction of agricultural reservoirs. We investigated water balance of reservoir through simulation of three types of water supply demands such as agricultural water, agricultural water and river maintenance flow, and agricultural water and environmental ecology flow. The economics analysis was conducted on water supply demands and corresponding remodeling or construction of reservoirs. As a result, it was found that the method of securing through heightening existing reservoir enhancement is economically feasible. However, it was not possible to secure all the amount of the EEF due to the size limitation of existing reservoirs or constrain of the watershed for newly built reservoir. Therefore, in order to secure all of the EEF, the utilization of other alternatives as well as agricultural reservoirs should be considered. This study demonstrated the method of economical feasibility study of securing river maintenace flow and EEF using agricultural reservoirs and other considerations.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.1732-1736
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• 2008

The characteristics of a river flow analysis are significant for river maintenance plan. At the present time, HEC-RAS, 1-Dimensional Numerical Analysis Model, is mainly applied to analyze the character of a river flow. The shape of a river is somewhat in longitudinal linear form. It was suspected that the usage of 1-dimensional numerical analysis model is more economical. Development of numerical analysis models and computers are possible to calculate large volume. Hence, it is possible to adapt the analysis of the key stations by 2-dimensional numerical analysis model. The limitation of 1-Dimensional Numerical Analysis Model is that it is hard to evaluate structure affection of numerical simulation by energy loss coefficient at river structure analyzing. When adaptation of the 2-dimensional numerical analysis model in river structure ensues, it takes more objective analyzing than 1-dimensional numerical analysis model for flow affection by river structure. 2-dimensional numerical analysis model consults with the different structure position of hydraulic characteristics and different water depth of shape and scope in vertical flow. 1-dimensional numerical analysis model is possible to simulate with only energy loss coefficient for sudden river section changing, sudden waterway changing by curved. 2-dimensional numerical analysis model use original geographical features. So the model removes technical subjectivity of faulty judgment. It is an objective analysis.

• 한국관개배수논문집
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• 제10권2호
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• pp.88-100
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• 2003

• Structural Monitoring and Maintenance
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• 제6권2호
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• pp.85-101
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• 2019

The effects of foundation scour depth and riverbed condition on the natural frequencies of a typical cross-river integral abutment bridge have been studied. The conventional operational modal analysis technique has been employed in order to extract the modal properties of the bridge and the results have been used in the Finite Element (FE) model updating procedure. Two tests have been carried out in two different levels of water and wet condition of the riverbed. In the first test, the riverbed was in dry condition for two subsequent years and the level of water was 10 meter lower than the natural riverbed. In the second test, the river was opened to water flow from the upstream dam and the level of water was 2 meter higher than the natural riverbed. The results of these two tests have also been used in order to find to what extend the presence of water flow in the river and saturation of the surrounding soil affect the bridge natural frequencies. Finally, the updated FE model of the bridge has been applied in a series of parametric analyses incorporating the effect of piles' relative scour depth on the bridge natural frequency of the first four vibration modes.

• 한국습지학회지
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• 제16권2호
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• pp.213-220
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• 2014

최근 하천정비는 환경에 대한 인식이 높아지면서 이수 및 치수뿐만 아니라 하천환경에 대한 관심이 증가하는 쪽으로 바뀌어가고 있는 실정이다. 따라서, 하천환경 또는 하천복원이 하천사업의 핵심이 되고 있다. 우리나라의 경우, 대부분의 하천이 치수목적의 하천정비에 의해 홍수조절과 주운을 돕기 위해 직강화 되었다. 하도를 직강화 할 경우 안정성 유지가 중요하므로 하천을 따라 제방이 축조된다. 이와같이 이수와 치수를 목적으로 하천에 축조된 댐, 보, 제방 및 수문 등과 같은 구조물의 경우, 하천의 종 횡적 연결성(Connectivity)을 저해하는 요인이 된다. 연결성이란 어떤 서식처에서 다른 서식처로 에너지와 물질을 이동시키거나 자연적인 수로를 통하여 서식처 간을 물리적으로 연결하는 동적인 자연통로로써 장기적인 하천복원관점에서 볼 때 연결성 증대는 유역 내 건강한 생태계 조성을 위해 매우 중요하다. 본 연구에서는 횡적 연결성 회복을 통한 하천복원의 첫 번째 단계로써 연결성에 대한 기본개념을 설명하고 대상유역을 선정하여 연결성을 저해하는 격리, 차단 공간의 유무에 따른 유역 내 흐름양상의 변화를 수치모의 하였다. 본 연구의 결과는 유역 내 수리수문연결기술 개발로 이어질 수 있을 것으로 판단되며, 차후 하천복원사업에 기여할 수 있을 것으로 판단된다.

• 한국방재안전학회논문집
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• 제16권2호
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• pp.57-63
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• 2023

기후변화로 인하여 발생하는 집중호우와 슈퍼태풍은 우리나라에서 많은 피해를 야기한다. 이러한 피해를 저감하기 위해서 다양한 형태의 하천정비사업이 추진되고 있으나, 홍수기와 갈수기가 뚜렷한 우리나라에서는 하천 균형을 유지하기가 어렵다. 특히, 하천정비 사업으로 설치된 하천구조물은 홍수기에 구조물 및 그 기초의 세굴이 발생되고 하상 변화 등 다양한 문제를 일으키고 있다. 이러한 하상세굴을 저감하기 위하여 하천의 만곡부에 다양한 베인이 많이 설치되며, 베인의 배치와 크기, 모양에 따라서 다양한 하상세굴 저감 효과가 나타난다. 베인은 원심력에 의해 발생하는 2차 흐름과 반대 방향으로 2차 흐름을 다시 생성함으로써 외측 하상 주변의 세굴이 감소하고 퇴적이 촉진된다. 본 연구의 이론은 질량보존법칙을 만족하는 연속방정식과 운동량 보존을 만족하는 운동량방정식을 적용한 지배방정식을 이용하고, 다양한 조건 하에서 베인의 영향을 조사하기 위해 설계 요인에 따라 전체 평균 유속 변화율을 측정한다. 사다리꼴 베인과 사각형 베인 모두에서 평균유속과 횡단면 유속이 모두 감소하였고, 이는 베인 설치로 인해서 원심력을 갖고 유하하는 하천유속이 방해를 받아 유속이 저감되기 때문이다. 또한, 하천흐름 방향에 수직으로 또는 경사적으로 설치된 베인은 원심력에 의해 발생하는 2차흐름의 역방향으로 2차흐름을 발생시켜 원심력 2차흐름의 상쇄를 나타내기 때문에 베인의 효과가 나타난다.