• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.224-224
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• 2023

국내·외로 Soil and Water Assessment Tool (SWAT) 모델은 유역 단위에서 유출 및 수질을 예측하는데 활용되고 있다. 하지만 SWAT 모델의 결과물은 데이터 테이블 형식으로만 이루어져 있기 때문에 모델 사용자가 유역 내 하천별 수문 모의 결과물을 직관적으로 확인하기 어렵다는 단점이 있다. 최근 다양한 분야에서 3D 가상환경을 구축하는데 디지털 트윈 기술의 활용성이 증가하고 있다. 디지털 트윈 기술은 현실의 공간을 가상환경으로 구축해 실시간 현실의 상황을 파악하여, 의사결정 지원을 제공한다는 장점이 있다. 이에 본 연구에서는 디지털 트윈 기술과 SWAT 모델을 연계하여, 모델의 결과값을 가상환경 3D 지도인 CESIUM에 실시간으로 표출할 수 있는 디지털 트윈 기반 SWAT 모델 수문 모의 시스템을 개발하였다. 이 시스템은 3D 지형에 SWAT 모델을 통해 모의 된 하천의 수위 및 SS에 대한 표출이 가능할 뿐만 아니라 기후나 유역환경에 따른 유역 내 수문 변화를 시·공간적으로 파악할 수 있는 장점이 있다. 향후 본 연구에서 개발된 디지털 트윈 기반 SWAT 모델 수문 모의 시스템은 홍수 및 가뭄과 같은 재해에 대응할 수 있는 유역 및 하천관리 대책을 효율적으로 수립하는데 활용될 수 있을 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.334-334
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• 2020

우리나라는 서울지역과 수도권 위성도시의 인구분포가 집중되어있으며, 도시지역에 대한 관거 우선 확충에 따라 하수처리구역의 비율이 점차 늘어나고 있다. 초기우수월류에 의한 오염은 비점오염원의 경우로, 발생 및 배출경로가 다양하고 불특정하게 발생한다. 비점 오염원의 유출 농도는 강우 초기에 높게 나타나고, 점차 농도가 낮아지는데, 이러한 강우 특성을 고려하여 오염발생량을 규명하는 것이 필요하다. 이에 따라 본 연구에서는 중랑천 의정부 지역을 대상지역으로 선정하여, 합류식 하수관거 월류부하를 하수도법 관리수준으로 제어하기 위한 초기우수 처리대상 강우량을 산정하고 강우분포형 및 토지이용도 현황별로 초기월류유량 및 부하특성을 검토하였다. 본 연구에서는 SWMM(Strom Water Management Moder)모형을 적용하여, 매년 홍수기에 발생할 수 있는 다양한 강우분포를 고려하여 대상유역의 토지용도별 합류식 처리구역에 대하여 SWMM 모형의 검·보정 절차를 통해 예측값과 측정값 사이의 상관관계를 분석하였고, 의정부 지역의 초기우수월류 오염부하량의 토지용도에 따른 경향성과, 강우량 및 강우분포, 배수면적에 따른 경향성을 비교하였다.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.547-565
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• 2011

Different types of schemes have been used in stage prediction involving conceptual and physical models. Nevertheless, none of these schemes can be considered as a single superior model. To overcome disadvantages of existing physics based rainfall-runoff models for stage predicting because of the complexity of the hydrological process, recently the data-derived models has been widely adopted for predicting flood stage. The objective of this study is to evaluate model performance for stage prediction of the Neuro-Fuzzy and regression analysis stage prediction models in these data-derived methods. The proposed models are applied to the Wangsukcheon in Han river watershed. To evaluate the performance of the proposed models, fours statistical indices were used, namely; Root mean square error(RMSE), Nash Sutcliffe efficiency coefficient(NSEC), mean absolute error(MAE), adjusted coefficient of determination($R^{*2}$). The results show that the Neuro-Fuzzy stage prediction model can carry out the river flood stage prediction more accurately than the regression analysis stage prediction model. This study can greatly contribute to the construction of a high accuracy flood information system that secure lead time in medium and small streams.

• Journal of Korea Water Resources Association
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• v.45 no.6
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• pp.607-616
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• 2012

The objective of this study is to evaluate the valid forecast lead time and the accuracy when AWS observed rainfall data are used for real-time river flow forecast. For this, Namhan river basin is selected as study area and SURF model is constructed during flood seasons in 2006~2009. The simulated flow with and without the assimilation of the observed flow data are well fitted. Effectiveness index (EI) is used to evaluate amount of improvement for the assimilation. EI at Chungju, Dalcheon, Hoengsung and Yeoju sites as evaluation points show 32.08%, 51.53%, 39.70% and 18.23% improved, respectively. In the results of the forecasted values using the limited observed rainfall data in each forecast time before peak flow occur, the peak flow under the 20% tolerance range of relative error at Chungju, Dalcheon, Hoengsung and Yeoju sites can be simulated in forecast time-11h, 2h, 3h and 5h and the flow volume in the same condition at those sites can be simulated in forecast time-13h, 2h, 4h and 9h, respectively. From this results, observed rainfall data can be used for real-time peak flow forecast because of basin lag time.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.1
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• pp.69-78
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• 2008

An integration study of watershed model(HSPF, Hydological Simulation program-Fortran) and reservoir water quality model (CE-QUAL-W2) was performed for the evaluation of turbid water management in Yongdam reservoir. The watershed model was calibrated and analyzed for flow and suspended solid concentration variation during rainy period, their results were inputted for reservoir water quality model as time-variable water temperature and turbidity. Results of the watershed model showed a good agreement with the field measurements of flow and suspended solid. Also, results of the reservoir water quality model showed a good agreement with the filed measurements of water balance, water temperature and turbidity using linkage of the watershed model results. Integration of watershed and reservoir model is an important in turbid water management because flow and turbidity in stream and high turbidity layer in reservoir could be predicted and analyzed. In this study, the integration of HSPF and CE-QUAL-W2 was applied for the turbid water management in Yongdam reservoir, where it is evaluated to be appliable and important.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.1
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• pp.179-192
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• 1993

Three-dimensional cohesive sediment transport model, COSETM-3, is develpoed using a finite difference method. The model results are compared with the physical experimental results for the relative concentration with time at the mid-depth of the recirculating flume and are found to be in good agreement. This model is applied to Suyoung Bay in Pusan of Korea to verify the field applicability of the model and to investigate on the SS (suspended solids) diffusion phenomena at the bay. Behaviors of discharging SS from Suyoung River at normal river flow and flood river flow are predicted. The numerical results appear to be reasonable and qualitative agreement with field data. The influence of settling velocity on the concentration distribution of SS is also investigated. In case of not considering settling velocity, SS concentration at surface layer is higher than that at lower layer, but in case of considering settling velocity, SS concentration at lower layer is higher than that at surface layer. The fluctuation of SS concentration at surface layer is large due to the strong mixing, but the fluctuation of the concentration at lower layer is small due to the weak mixing. SS diffusion patterns at flood river flow are similar to those at normal river flow, while the concentration at that flow is so much higher than that at this flow. SS concentration increases with time until the peak discharge occurs, but the concentration decreases with time with decreasing river flow after the peak discharge.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.308-320
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• 2021

An integrated sediment management approach that includes the recovery of the amount of declined sediment supply is effective as a fundamental solution to coastal erosion. During planning, it is essential to analyze the transfer mechanism of the sediments generated from estuaries (the junction between a river and sea) to assess the amount and rate of sediment discharge (from the river to sea) supplied back to the coast. Although numerical models that interpret the tidal sand bar flushing process during flooding have been studied, thus far, there has been no study focusing on the formation and development processes of tidal sand bars. Therefore, this study aims to construct wave deformation, flow regime calculation, and topographic change analysis models to assess the amount of recovered sediment discharge and reproduce the tidal sand bar formation process through numerical analysis for integrated littoral drift management. The tidal sand bar formation process was simulated, and the wave energy and duration of action concepts were implemented to predict the long-term littoral movement. The river flux and wave conditions during winter when tidal sand bars dominantly develop were considered as the external force conditions required for calculation. The initial condition of the topographic data directly after the Maeupcheon tidal sand bar flushing during flooding was set as the initial topography. Consequently, the tidal sand bar formation and development due to nearshore currents dependent on the incident wave direction were reproduced. Approximately 66 h after the initial topography, a sand bar formation was observed at the Maengbang estuary.

• Journal of Korea Water Resources Association
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• v.51 no.1
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• pp.71-80
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• 2018

For the stream management, time of concentration is one of the important factors. In particular, as the requirement about various application of the stream increased, accuracy assessment of concentration time in the stream as waterfront area is extremely important for securing evacuation at the flood. the past studies for the assessment of concentration time, however, were only performed on the single hydrological event in the complex basin of natural streams. The development of a assessment methods for the concentration time on the complex hydrological event in a single watershed of urban streams is insufficient. Therefore, we estimated the concentration time using the rainfall- runoff data for the past 10 years (2006~2015) for the Oncheon stream, the representative stream of the Busan, where frequent flood were taken place by heavy rains, in addition, reviewed the reliability using artificial neural network method based on Matlab. We classified a total of 254 rainfalls events based on over unrained 12 hours. Based on the classification, we estimated 6 parameters (total precipitation, total runoff, peak precipitation/ total precipitation, lag time, time of concentration) to utilize for the training and validation of artificial neural network model. Consequently, correlation of the parameter, which was utilized for the training and the input parameter for the predict and verification were 0.807 and 0.728, respectively. Based on the results, we predict that it can be utilized to estimate concentration time and analyze reliability of urban stream.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.545-553
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• 2021

The frequency by water disaster in urban areas are increasing continuously due to climate change and urbanization. Countermeasures are being conducted to reduce the damage caused by water disasters. An analysis based on permeability, one of the parameters that affect runoff, is needed to predict quantitative runoff in urban watersheds and study runoff reduction. In this study, the SWAT model was simulated for the oncheon stream basin, a representative urban stream in Busan. The permeability map was prepared by calculating the CN values for each hydrologic response unit. Based on the permeability map prepared, EPA SWMM analyzed the effect of LID technology application on the water cycle in the basin for short-term rainfall events. The LID element technology applied to the oncheon stream basin was rooftop greening in the residential complex, and waterproof packaging was installed on the road. The land cover status of the land selected based on the permeability map and the application of LID technology reduced the outflow rate, peak flow rate, and outflow rate and increased the infiltration. Hence, LID technology has a positive effect on the water cycle in an urban basin.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.113-113
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• 2016

기후변화로 인한 집중호우가 빈번히 발생하고 있으며, 도시지역에서는 호우에 의한 침수피해가 더욱 빈번히 발생하고 있다. 인구와 건물이 밀집한 도시지역은 불투수율이 높아 호우 발생시 홍수 위험도가 커지고 있으며, 침수에 의한 사유재산뿐만 아닌 사회기반시설에 대한 피해도 증가하고 있다. 도시는 건물과 건물 사이로 도로 네트워크가 복잡하게 설계되어있다. 이러한 건물과 도로들은 투수성이 떨어지며, 지하공간과 건물들이 발달하여 유역지표면의 가하학적 형상이 매우 복잡하게 변화하고 있다. 도시지역은 저류 및 침투능이 부족하고, 지역의 특성에 따라 내수배제시설이 부족하여 우수관망에 대한 우수배제의 의존도가 높으며, 호우에 의한 침수와 관거 월류에 의한 침수피해 발생시 우수는 도로를 따라 저지대로 흐르며 침수지역이 넓어지게 된다. 이와 같은 도시지역의 침수를 예측하기 위한 침수해석에는 지형의 높낮이, 형상을 고려한 예측이 필요하다. 특히 건물 및 도로망이 복잡한 지역일수록 지형이 정교하게 고려되어야 한다. 지형이 적절히 고려되지 않은 침수해석은 침수예상지역을 다소 과대 또는 과소하게 나타낼 수 있고, 침수심을 제대로 반영하지 못한 결과가 도출될 수 있다. 건물과 도로가 밀집된 도시지역에서 이러한 문제가 발생할 경우 예상치 못한 지역에서 침수가 발생하여 피해를 줄 수 있으며, 이는 곧 인명과 재산피해로 이어지게 된다. 본 연구에서는 과거 침수피해가 있었던 도림천 유역을 대상으로 지형자료의 해상도에 따른 침수분석을 실시하였다. 우수관망과 도시지역의 유출모의에 적합하다고 알려진 SWMM 모형을 활용하여 LiDAR(Light Detection And Ranging), 10m DEM, 1:1,000 수치지형도를 활용하여 지형상세도의 변화에 따른 침수모의를 실시하였다.