• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.908-911
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• 2004

The purpose of this study is to investigate the applicability of the two dimensional model in natural rivers. In this study, two dimensional unite element model, SMS, is used to simulate a complex flow along with the sediment movements in the natural river. The RMA-2 model embeded in SMS is used to simulate flow phenomena and SED-2D model is employed to simulate sediment transport. The model is applied to the confluence zone of the Gam River and mouth of Nakdong River. For model calibration, the result of the unsteady flow analysis is compared with the Typhoon 'Rusa' data. In addition, the runoff analysis was conducted for the determination of the project flood and the flood forecasting. The simulation results presented the characteristics of two dimensional flow with velocity vector and flow depth. The sediment transport characteristics are shown in terms of sediment concentration as well as bed elevation change. Accordingly, the SMS model in this study turned out to be very effective tool for the simulation of the hydrodynamic characteristics under the various flow conditions and corresponding sediment transports in natural rivers.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.1
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• pp.94-104
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• 2004

The purpose of this study is to analyze various hydraulic characteristics using SMS (Surface Water Modeling System) RMA2 model. It is based on 2-D finite element method. River reaches (13.8km) from Gyeongan gauge station to the inlet of Paldang lake was selected. Finite element was made by RIMGIS Data, and the analysis of river-changes was operated by unsteady flow. The sediment concentration and bed change was simulated using SED2D model. This River's velocity was distributed that 0.05~3.85m/s and bed change was changed about 0.0003~0.0135m.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.1 s.20
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• pp.69-81
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• 2006

The purpose of this study is to identify the downstream influences due to the dam discharge by using 2-dimensional model, SMS(Surface water Modeling System). RMA-2 and SED-2D in SMS were applied to Yongdam multipurpose dam watershed located in Gum river basin. Through the simulation, erosion and deposit quantitative analysis of sinuous channels and scour pattern analysis of bridges have been done. A differences erosion depths between deposit are simulated as $-102.4 mm{\sim}54.2 mm$ at No.176(1.4 km) and $-104.1 mm{\sim}28.9 mm$ at No.146(7.4 km), sinuous channel. The river bed at Kamdong bridge in straight channal is simulated as uniform erosion. However, the river bed at Dumdul bridge in sinuous channal has been shown as different erosion depths at each sides. Consequently, the parts that could not be simulated on the existing 1-dimensional model, can be improved results by using a 2-dimensional model, about weakness points for hydraulic modeling such as extreme bend, tributary confluence.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.4
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• pp.91-97
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• 2009

The flow is changed by the structure which goes across the river. The structure with debris causes high water level and overflow. The changed flow, which caused by pier and stream characteristics like velocity and slope, was analysed by 2D model. After rainfall, the influences of increased discharge were evaluated. Velocity was simulated in the channel by SMS (Surface water Modeling System) using RMA2, and high velocity values were found in the steep and narrow reach. Highest velocity value around piers was showed in the middle of space between two piers. The increased discharge due to rainfall increases velocity and changes flow contour considerably.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.519-522
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• 2003

The purpose of this study is to analyze various hydraulic characteristics using SMS (Surface Water Modelling System) RMA2 model. It is based on 2-D finite element method. River reaches (13.8km) from Gyeongan gauge station to the inlet of Paldang lake was selected. Finite element was made by RIMGIS Data, and the analysis of river-changes was operated by unsteady flow. The sediment concentration and bed change was simulated using SED2D model.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.124-135
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• 2007

The purpose of this study is to analyze the hydraulic behavior in a stream reach using SMS RMA-2 model with a series of dynamic boundary conditions of main stream and lateral flows simulated by WMS HEC-1 program. For the stream reach (10.5 km) between Gongdo and Pyeongtaek water level gauge stations of Anseongcheon, the model simulated two dimensional flow characteristics by applying dynamic flow conditions of rainfall frequencies of 50, 100, 500, and 1,000 years for the main stream and three tributaries. The temporal flow behavior successfully simulated and the results showed that the distribution of mean velocity and water level within the stream reach increased according to the increase of flow frequency. Especially, the flow velocity sensibly increased at the near downstream of lateral inflow as the width of main stream is narrower.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.571-580
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• 2013

In this study, compared with the result of water surface elevation and water velocity on the establishment of river maintenance basic plan and result of HEC-GeoRAS based GIS, and after use the result of water surface elevation and velocity were observed in the Han stream on Jeju island, analysis 2 dimensional stream flow. the lateral hydraulic characteristics and curved channel of the stream were analyzed by applying SMS-RMA2 a 2 dimensional model. The results of the analysis using HEC-RAS model and HEC-GeoRAS model indicated that the distribution ranges of water surface elevation and water velocity were similar, but the water surface elevation by section showed a difference of 0.7~2.18 EL.m and 0.63~1.16 EL.m respectively, and water velocity also showed differences of maximum 1.58m/sec and 2.67m/sec. SMS-RMA2 analysis was done with the sphere of Muifa the typhoon as a boundary condition, and as a result, water velocity distribution was found to be 1.19 through 3.91 m/sec, and the difference of lateral water velocity in No. 97 through 99 the curved channel of the stream was analyzed to be 1.59 through 2.36 m/sec. In conclusion it is anticipated that the flow analysis of 2 dimension model of stream can reflect the hydraulic characteristics of the stream curved channel or width and shape, and can be applied effectively in the establishment of river maintenance basic plan or management and designing of stream.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.599-602
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• 2007

Flood damage has been increased due to abnormal climate and extreme rainfall. Especially, the increase of impervious areas and the decrease of flow travel times due to the urbanization have been caused heavy division of flood with the recent rainfall characteristics. In this study, hydrodynamics flow analysis has been needed two dimensional numerical analysis for correct stream flow interpretations on bridges as hydraulic structures in rivers. Therefore, comparative analysis has been accomplished by using HEC-RAS model and SMS-RMA2 model for one and two dimensional flow. Also, flood characteristics have been analyzed in urban stream basin.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1407-1411
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• 2007

현재까지 우리나라에서 주로 사용되고 있는 2차원 흐름 해석모형은 미연방 도로국(U.S. Federal Highway Administration)과 연계하여 Brigham Young University에서 개발된 SMS(Surface-Water Modeling System) 모형이다. SMS모형 중 이송 확산 모형으로는 RMA-4가 포함되나 이 모형은 최신 수치기법을 반영하지 못하는 등의 문제점들로 인해 실제 물리적 현상 모의에 있어서 한계를 가지고 있다. 따라서 물리적 현상에 대한 적절한 모의를 위한 개선과정을 통하여 RAM4가 개발되었다. 본 연구에서는 현장실측 자료를 바탕으로 RMA-4와의 모의결과 비교를 통하여 오염 확산 해석모형인 RAM4의 적용성을 검증하고자 하였다. RAM4와 RMA-4 모의에 있어서 격자구성과 경계조건은 동일하게 설정하였으며, 유량조건은 평수량과 갈수량으로 선정하였다. 각각의 유량시 수위조건이 틀려지므로 각 유량조건에 대한 격자구성을 달리하였다. 모의구간은 낙동강 본류의 수산대교에서 삼랑진 철교까지의 약 13km 구간을 대상으로 하였다. 모의 구간내에는 밀양-하남 하수처리장이 상류 좌안측에 위치하고 있고, 만곡, 단면의 축소 및 확대, 하중도, 합류 등의 지형학적 특징들이 비교적 짧은 구간에 나타나고 있어 모형의 검증에 적합하다고 판단된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6B
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• pp.515-522
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• 2011

The hydrodynamic models are widely used in the research for analysis of flow characteristics and design of hydraulic structure and river channel. These models need to be calibrated with observed data. But, there are few field data of two-dimensional flow velocity in flood because the direct measurement of the flood flow velocity are very dangerous. For this reason the results of two-dimensional numerical models are usually calibrated and verified with only a few observed data. Moreover, the verification of numerical models for the design flood is usually carried out using the result of one-dimensional model, HEC-RAS. In this study, using the flow velocity profile extracted from the aerial photos of a flood of the Tone River in Japan, two-dimensional numerical models, RAM2 in RAMS, RMA2 in SMS, and one-dimensional numerical model, HEC-RAS which are most widely used in research and design work are verified and the validity for verification of two-dimensional models with HEC-RAS is reviewed. The results showed that the water surface elevation of HEC-RAS, RAM2 and RMA2 models have similar results with observed data. But, the velocity results of RAM2 and RMA2 models in the floodplain have some difference with the velocity from aerial photo analysis. And the velocity result of HEC-RAS has big difference with the sectional averaged value of velocity from aerial photo analysis.