• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.488-493
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• 2006

Accurate river discharge is the most important factor in managing river basins and for successfully maintaining total maximum daily loads in Korea. It is not easy to measure the discharge directly in large rivers owing to physical and environmental constraints, even after investing much time and money. Recently, to overcome these historical drawbacks in river discharge measurement, we have developed the Automatic Discharge Acquisition & Management System (ADAMS) that scans the river cross-section and measures each cell $(1m{\times}1m)$ velocity using HADCP. The hardware system is composed of an HADCP sensor and winch, as well as a PC and software system for the discharge calculation module and hardware control module. It is controlled remotely via the internet and uses the velocity-depth integration method and the velocity-contour method for calculating river discharges. The characteristics of ADAMS are a ubiquitously accessible system, featuring real time automatic discharge measurement, remote control via the internet. The results using ADAMS at the Jindong stage site show less than 5% uncertainty and are 4 times more efficient than the ADCP & Q-boat system. This system can be used to measure any large river, river mouth or tributary river affected by backwater, all of which have a very difficult measuring real time discharge. The next generation of ADAMS will feature an upgrade to increase portability and GPS integration.

• 한국해양공학회지
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• 제20권3호
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• pp.61-66
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• 2006

The estuary has a very complex coastline and bottom topography. Before the close of floodgate, the Keum river estuary was deposited with sediment from the Keum river, created bythe construction of the Keum river estuary dike. So, a periodical dredging is necessary to assure water depth for boat entry and departure to Kunsan port. Theof this study is to find the change of tidal current of M2tide and the topography before and after construction at the Geum River estuary dike. The change of water depth is investigated by digitizing the sea map (No.305) of Kunsan port, which was edited by National Oceanographic Research Institute. The calculated co-range and co-tidal charts of M2tide before the dike construction are similar to the observed ones. Therefore, the amplitude and phase after construction at Geum River estuary dike increases compared to before construction at Geum River estuary dike. The scour occurred in the A-A' section.

• 한국산학기술학회논문지
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• 제14권2호
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• pp.911-918
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• 2013

2차원 RMA2 모형을 이용하여 방류조건에 따른 댐하류 하천의 홍수위, 유속분포 및 하상변동을 분석하였다. 수위분석결과 200년빈도에 의한 영향은 주암댐에서 광천교까지 구간(1.27km)에서 나타났고, 여유고는 댐 직하류 좌안제방 300m 구간에서 0.7m 부족하였다. PMF 방류시는 보성강 전구간에서 제방을 월류하는 것으로 분석되었다. 침수범람구역은 200년 빈도에서는 하천합류부의 일부지점에서 발생하였고, PMF 방류시에는 제방월류로 침수구역이 확대되었다. 하도내의 유속은 교량 및 하도의 폭이 좁은 구간에서 비교적 유속이 크게 나타나 하상저하가 발생하였다.

• Water Engineering Research
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• 제3권1호
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• pp.45-55
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• 2002

The Szentgotthard Flood Protection Project is located in the southeasters part of Austria, very close to the Hungarian border and to the Hungarian town of Szentgotthard situated near the Junction of the rivers Lafnitz and Raab. During heavy rainstorms, this area has always been liable to severe floodings, affecting the town itself and upstream reaches, where major industrial and commercial development is planned. In order to solve these problems, several solutions have been developed by means of a series of model tests performed at the hydraulic laboratory of the Technical University of Graz, Austria. The model was constructed to scales 1:75 (lengths) and 1:25 (heights). This trebled scale allowed greater accuracy in the measurement of discharge depths. The results from the model tests have led to the following proposals: - Construction of a flood relief trough with an inflow section 3.5 km upstream of the junction of the rivers Lafnitz and Raab. - Use of a former river bed for the flood relief trough. - Design of a lowered embankment crest section to pass one-third of the maximum flood flow of the river Lafnitz. - Connection of the flood relief trough to the Lahnbach stream, a tributary of the river Raab.

• 한국환경과학회지
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• 제2권3호
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• pp.227-233
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• 1993

Laboratory batch experiments were conducted, using suspended solids and sediments taken. from a tidal section of the Rokkaku river, to study the effect of salinity on nitrification and to estimate kinetic parameters of it. Experimental results indicated much more inhibitation of ;$NO_2$-N oxidation by chlorides than that of $NH_4$-N oxidtion. Nitrifying bactema in sediments were less sensitive to chlorides than those in SS. The change of nitrogen concentration with time was clearly explained with the Monod growth model and the kinetic parameters were obtained by the curve fitting method.

• 한국산학기술학회논문지
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• 제7권6호
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• pp.1264-1270
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• 2006

본 연구에서는 달천 하류의 수리적 특성 및 유사론적 특성을 파악하기 위해 준2차원 모형인 GSTARS 2.1 모형을 적용하였다. GSTARS 2.1 모형에 포함된 Meyer-Peter와 Muller공식, Acker와 White's공식, Engelund와 Hanson공식 그리고 Yang공식의 네 가지 유사이송공식을 1984년부터 1992년까지의 하상단면에 대해 모의하였으며, 그 결과 Meyer-Peter와 Muller공식이 실측치에 근사한 것으로 나타났다. 정량적인 비교에서 각 단면별로 92년 실측치보다 모형에 의한 계산치가 하상변동량이 약간 과소로 산정되었다. Meyer-Peter와 Muller공식을 적용하여 유관 개수에 따른 하상변동의 효과를 분석하였다.

• Geomechanics and Engineering
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• 제32권6호
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• pp.601-613
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• 2023

Low liquid limit silt, widely distributed in the middle and down reaches of Yellow River, has the disadvantages of poor grading, less clay content and poor colloidal activity. It is very easy to cause vehicle jumping at the bridge-embankment transition section when the low liquid limit silt used as the backfill at the abutment back. In this paper, a series of laboratory tests were carried out to study the physical and mechanical properties of the low liquid limit silt used as back filling. Ground granulated blast furnace slag (GGBFS) was excited by active MgO and hydrated lime to solidify silt as abutment backfill. The optimum ratio of firming agent and the compaction and mechanical properties of reinforced soil were revealed through compaction test and unconfined compressive strength (UCS) test. Scanning electron microscope (SEM) test was used to study the pore characteristics and hydration products of reinforced soil. 6% hydrated lime and alkali activated slag were used to solidify silt and fill the model of subgrade respectively. The pavement settlement regulation and soil internal stress-strain regulation of subgrade with different materials under uniformly distributed load were studied by model experiment. The effect of alkali activated slag curing agent on curing silt was verified. The research results can provide technical support for highway construction in silt area of the Yellow River alluvial plain.

• 한국환경생태학회:학술대회논문집
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• 한국환경생태학회 2005년도 정기총회 및 학술대회
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• pp.137-140
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• 2005

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.1138-1142
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• 2005

The tidal river is a river affected by tide, which causes the water level to rise and fall two times everyday periodically. The local velocity across the river could be very fast because of the cross-sectional characteristics of the river even though it's not a rainy season. Therefore extreme local scour could take place around hydraulic structures such as piers and caissons due to backward flow velocity. For the construction of pier foundation of Ilsan-bridge In the Han River, the field observations were performed to get the velocity and water level. The numerical analysis was performed by HEC-RAS(UNET). The relationship between measured maximum velocity and calculated mean velocity is achieved, which is used to estimate the velocity and water level as the construction is proceeding. Countermeasures for scour were designed with the results of the hydraulic analysis to avoid potential damage during construction work. According to the results of monitoring, the velocity increase after temporary road embankment was negligible, from which it is considered that the degradation of main channel compensated for the constriction of cross-section by embankment.

• 산업기술연구
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• 제26권A호
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• pp.129-137
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• 2006

In this research, we made a one and two-dimensional analysis of numerical data collected from the bend curvature of a bended river section. According to the result from the numerical analysis, the inflow ＆ output angle caused a water level deviation which increased with an increase of the flood discharge. From the water level deviation of our two-dimensional numerical model, we obtained the maximum slope of 6,67% when the inflow and output angle was 105 degrees and the flood discharge was 500 CMS. As for the right side, the differences with the one-dimensional numerical model were reduced when the angle was more than $90^{\circ}$. As for the left side the differences were reduced when the angle was more than $105^{\circ}$. For a river with more than 90 degrees bend curvature, a hydraulic experiment would be more appropriate than a numerical analysis.