• Journal of Korea Water Resources Association
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• v.35 no.6
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• pp.693-701
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• 2002

In this study, one dimensional sediment movement numerical model(HEC-6) and semi-two dimensional sediment movement numerical model(GSTARS 2.1) were applied to solve the change of channel geometry in Bocheong stream. GSTARS 2.1 model was applied for the three selected sediment transport formulas(Ackers and White's, Engelund and Hanson, Yang formula) from 1993 to 2000 measured data on each section. The simulation results of Ackers and White formula for long -term bed changes are good when compared to the measured data. The HEC-6 model was applied for the simulation of one dimensional sediment movement for the same period. Comparison of the long-term simulations by GSTARS 2.1 and HEC-6 models with measured data shows that simulations by both models are in fair agreement with measured data in overall trend of the river bed changes. Comparisons of simulated cross sectional bed-elevations with measured data shows that GSTARS 2.1 model gives better agreement with than simulated results bed changes on the HEC-6 model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1264-1270
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• 2006

In this study, semi-two dimension numerical model(GSTARS 2.1 model) were applied to study on the hydraulic and sedimentologic characteristics of downstream channel section in Dal stream. GSTARS 2.1 model was applied for the four selected sediment transport formulas(Meyer-Peter and Muller, Acker and White's, Engelund and Hanson, Yang formula) from 1984 to 1992 measured data on each section. The simulation results of Meyer-Peter and Muller formula for long-term bed changes are good when compared to the measured data. When quantitatively compared, it appears that the results data is relatively underestimated compared to the 1992 measured data on each section. Using Meyer-Peter and Muller formula, analyse the effects of bed changes by stream tube number.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.117-125
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• 2011

River bed variation drops storage capacity of dams and reservoirs, and furthermore deteriorates safety of banks and peers. Therefore, understanding of bed variation is important to use and manage river water. Study section is downstream part of Ji- Cheon nearby Ji-Cheon Bridge which is located in Gum river basin. The river surveying at fourteen places with the length of 1,320m were undertaken on November 7, 2003 and September 24, 2004, and the results of river surveying were analyzed for the study. Real bed variation was compared with the simulation results of HEC-6 and GSTARS 3.0. Cross section data for the simulation of HEC-6 and GSTARS3.0 were composed of the basis of river surveying data on November 7, 2003. Hydrological data were acquired from Gu-Ryong watermark located at Ji-Chun Bridge. The research results revealed that when using Toffaleti equation, simulation results of two models were similar to the real bed variation. The bed variation simulated by using GSRARS 3.0 with only one stream tube was similar to the real bed variation. The bed variation simulated by using two models(HEC-6 and GSTRARS 3.0) with Toffaleti equation was also similar to the real bed variation. Therefore, it is expected that HEC-6 and GSTARS 3.0 models have applicability to predict the bed variation at the downstream of Ji-Cheon.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1B
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• pp.1-7
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• 2012

Quasi-two dimensional numerical model (GSTARS) was applied to determine the optimal sediment discharge formula for simulating the sedimentologic characteristics of Hyeongsan river. The field measurements have been conducted to obtain the data, such as sediment discharge, bed material, and channel geometry, for model calibration and verification. The sediment discharge formulas, which have been generally used, have been assessed according to the average error, relative error, RMSE, RRMSE, discrepancy ratio and Nash-Sutcliffe efficiency coefficient for bed changes along the thalweg. From the results, Laursen formula(1958) shows the best performance to simulate the long-term bed change of Hyeongsan river.

• Journal of Korea Water Resources Association
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• v.32 no.2
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• pp.131-142
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• 1999

In this study, one and semi-two dimensional numerical models were applied to study on the hydraulic and sedimentologic characteristics of upstream and downstream channel section near the Buyeo intake towers. The HEC-6 model was applied for the simulation of one dimensional sediment movement from 1988 to 1996, and GSTARS model was applied for the simulation of semi-two dimensional sediment movement for the same period. After the verification of accuracy of HEC-6 and GSTARS models, the models were applied again to predict the sediment movement near intake towers from 1988 to 2001. In this case, measured channel section of 1988 was used as an initial channel condition, and used to predict the long-term variation of channel section of 2001 after 13 years since 1988. The simulation results show that the channel bed is sedimented and eroded repeatedly in the main channel of overall study area, and that channel bed is getting elevated in the near Buyeo intake towers.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1103-1107
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• 2005

경기도 안양시 만안구 안양3동에 위치한 안양대교보는 길이 40m, 높이 1.3m의 농업용수 취수를 위한 보였으나 도심화로 인하여 원기능을 상실하였다. 수차례에 걸친 개수와 러버보를 설치하는 등 개량하였으나 효능이 약화되어 철거계획이 수립되어 있다. 본 연구에서는 준 2차원 모형인 GSTARS 3.0 모형을 안양천에 적용하여 안양대교보 철거로 인한 하상변동을 모의하여 1차원 유사이동 모형인 HEC-6 모형과 비교하였다. 단면자료는 2000년에 측정된 자료로 구성하였고, 입력자료에 사용된 하상토 자료는 2005년 안양천에서 채취된 자료를 사용하였으며, 유량자료는 2000년 6월부터 10월까지의 유량 관측치를 사용하였다. Meyer-peter와 Muller공식, Ackers 와 White 공식, 그리고 Yang공식의 세 가지 유사이송공식을 사용하여 각각의 공식을 사용하는 데 따른 계산결과를 비교하였다.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.297-300
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• 2002

Semi-two dimension numerical models were applied to study on the hydraulic and sedimentologic characteristics of upstream and downstream channel section in Dal stream. The feature of this paper is (1) to analyse the effects of bed changes by sediment transport formulas, (2) to analyse the effects of bed changes by stream tube. The simulation results of Meyer-peter and Muller formula for long-term bed changes are good when compared to the measured data.

• Journal of Wetlands Research
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• v.13 no.2
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• pp.329-341
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• 2011

This study was conducted with the national river, Munsancheon, which is located in Paju-si, Gyeonggi-do. The sediment discharge of Munsancheon was directly measured to analyze the sediment characteristics, and the results were used in the numerical model to predict the long-term river bed variation. The flow-total sediment discharge relation was derived using the measured total sediment discharge, and the results were compared with the total sediment discharge that was calculated using the existing prediction formula to derive a proper sediment discharge prediction method. In the actual measurements, the total annual sediment discharge was 5,478 ton/year, and the specific sediment discharge was 29.23 ton/$km^2$/year. The Ackers & White formula resulted in the values very close to the actual measurements. With the actual sediment discharge, geographical and hydrologic data as the input variables, HEC-6 and GSTARS models were comparatively analyzed. The test results showed that the HEC-6 model is suitable for the reliable prediction of the long-term river bed variation. Accordingly, the model was used for the long-term river bed variation prediction in this study. In the case of Munsancheon, deposition was continued in the downstream area and erosion occurred in the upstream area on the whole. It was expected that the stream would be stabilized in the river bed condition of 20 years later. The river bed variation was within 1 m, which was at the significance level. In the downstream area that is influenced by tide, however, the accumulation was continuously increasing within the section 2,000-7,000 m from the outlet. It seems that this should be considered in establishing the river management plans.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.338-338
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• 2016

준설은 흙 또는 모래, 자갈을 파내는 작업을 말하는 것으로, 준설의 목적은 수로, 하천, 항만공사에서 수심의 증가 및 수심을 유지하기 위함이다(산업안전대사전, 2004). 이러한 준설은 하천의 흐름 특성 및 제반 여건 변화를 수반하기도 한다. 준설 직후 낮아진 하상으로 인하여 수위가 감소되는 경우가 있으며, 반면에 수위 저하를 동반하지 않는 경우(저수지와 연결된 준설), 준설 부근에 퇴적이 발생하며 이는 하천의 수위 상승으로 연결될 수 있다. 이러한 수위 상승은 홍수 시 제방의 월류 가능성을 높이는 등 하천의 치수 안전성에 문제를 야기할 수 있다. 본 연구에서는 준설로 인한 하천의 수위 상승에 초점을 맞추었다. 기존 연구에서는 대부분 이러한 현상분석을 위해 수치해석을 이용하였으며, HEC-6, CCHE2D, GSTARS 등의 1, 2차원 수치해석 프로그램을 이용하였다. 그러나 1, 2 차원 수치모형은 수심에 따른 흐름특성을 충분히 반영하지 못하는 한계점을 가진다. 이에 본 연구에서는 3차원 수치해석 모형인 SCHISM을 이용하였다. SCHISM은 하구역의 흐름특성을 분석하기 위해 개발된 프로그램으로, 본 연구와 같이 단면의 급 확대부의 수치해석에 적합한 프로그램이라고 판단된다. 기존연구를 바탕으로 하상변동에 영향을 주는 인자를 산정하여 무차원화 하였으며, 하상 변동량 및 수위상승 영향의 민감도 분석을 수행하였다. 무차원인자는 준설깊이/상류수심(H/hu), 하류하폭/상류하폭($W_d/W_u$), 하류수심/상류수심($h_d/h_u$), 유량(Q)으로 결정하였다. 수치해석에 이용된 지형은 1: 2 경사의 제방을 가진 직선수로이며, 준설 구간을 기준으로 상 하류 각각 1,000 m의 길이를 확보하였다. SCHISM 수치모의를 통하여 민감도 분석을 수행한 결과 모든 수치해석 case에서 퇴적으로 인한 상류수위의 증가를 확인 할 수 있었다. 또한 하류수심/상류수심은 준설부 퇴적 및 상류 수위 상승에 가장 큰 영향을 주는 인자로 나타났다. 본 연구는 하천 준설 계획 시 참고자료로 활용이 가능할 것이며, 준설로 인한 하천수리특성 변화의 선행연구로써 의미가 있다고 판단된다.