• Journal of Korea Water Resources Association
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• v.44 no.12
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• pp.967-974
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• 2011

Based on daily time series from RDAPS numerical weather forecast, Streamflow prediction was simulated and the result of ESP analysis was implemented considering quantitative mid- and long-term forecast to compare the results and review applicability. The result of ESP, ESP considering quantitative weather forecast, and flow forecast from RDAPS numerical weather forecast were compared and analyzed with average observed streamflow in Guem River Basin. Through this process, the improvement effect per method was estimated. The result of ESP considering weather information was satisfactory relatively based on long-term flow forecast simulation result. Discrepancy ratio analysis for estimating accuracy of probability forecast had similar result. It is expected to simulate more accurate flow forecast for RDAPS numerical weather forecast with improved daily scenario including time resolution, which is able to accumulate 3 hours rainfall or continuous simulation estimation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.3
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• pp.773-784
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• 2014

This study evaluated the applicability of the Modified Bartlett-Lewis Rectangular Pulse (MBLRP) rainfall generation model for modeling extreme rainfalls and floods in Korean Peninsula. Firstly, using the ISPSO (Isolated Species Particle Swarm Optimization) method, the parameters of the MBLRP model were estimated at the 61 ASOS (Automatic Surface Observation System) rain gauges located across Korean Peninsula. Then, the synthetic rainfall time series with the length of 100 years were generated using the MBLRP model for each of the rain gauges. Finally, design rainfalls and design floods with various recurrence intervals were estimated based on the generated synthetic rainfall time series, which were compared to the values based on the observed rainfall time series. The results of the comparison indicate that the design rainfalls based on the synthetic rainfall time series were smaller than the ones based on the observation by 20% to 42%. The amount of underestimation increased with the increase of return period. In case of the design floods, the degree of underestimation was 31% to 50%, which increases along with the return period of flood and the curve number of basin.

• Journal of Korea Water Resources Association
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• v.43 no.3
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• pp.283-294
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• 2010

The objective of this study is to develop an accurate and stable dynamic water quality model which is capable of reflecting various flows and irregular cross sections and handling numerical oscillations under the low flow conditions. In order to solve the oscillation problem under the low flow conditions, diffusive wave method was applied to the low flow condition in developing a hydraulic model, DyHYD. DyQUAL is also developed as a water quality model to calculate up to 12 water quality variables including autochthonous BOD, water temperature, DO, TN and TP. The developed model is applied to both hypothetical river channels and actual Nakdong river watershed. Additionally, the applicability and reliability of the models are verified by comparing simulation results with observed values. Nash-Sutcliffe coefficients are estimated by comparison between simulation results and observed values. In the calibration and verification process, the coefficients varies from 0.391 to 0.591 and 0.704 to 0.902 for discharge, BOD, TN and TP, respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.6
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• pp.723-731
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• 2009

Recently, it has been strangely increasing rainfall and rainfall meter by global warming. so flood damage is being increase. It has happened there are so many damaged by influence by backwater of dam. However, the alleviative solutions of flood damages are focused on the lower river basin where the density of population is higher than upper river basin. This research proceeds based on design and build 3D topography model and reflects the topographical factors of upper river basin. It also simulated the circumstances of flooding by investigation of factors of outflow, hence, as a result, we would find out the vulnerable area for flooding and scale of damages effectively. This research suggests the solution and method of flooding for vulnerable area of the flooding to reduce the damages by predicting flooding. Thus, the suggestion may support to make a decision efficiently to prevent the damage of flooding.

• Journal of Korea Water Resources Association
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• v.30 no.5
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• pp.431-439
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• 1997

This paper describes the development of a decision support system (DSS) for the real time reservoir operation that aims to maximize the flood control effect. In the decision support system, model base and real time data processing subsystem are included along with the graphical user interface(GUI) that is able to visualize the forecasted runoff hydrographs at the flood control points and reservoir water levels resulting from the model run as well as the current hydrologic status. The system was verified through the pseudo real time applications to the Taechong reservoir operation with the historical flood events of the Kum river basin occurred in July, 1987 and August, 1995, Decision making processes were performed using the developed system and the results were compared with the real operations at that time. The reservoir operation using the pseudo real time application of DSS were simulated by the flood runoff simulation model, that shows the reservoir operation by DSS were successful in flood control for the lower Kum River.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.1
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• pp.29-37
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• 2021

It is important to introduce a local adaptive water supply system for upper mountainous regions, which provide a margin of water supply. This can be done through the process of securing a water source, planning for optimal use, and combining it with a water source that can be linked. In particular, in a mountainous region located at the uppermost part of the watershed, an approach should be found to utilize the groundwater discharge supplied through valley water and lateral discharge. This study sought to improve the water supply system using sand dams in drought-prone areas in Chuncheon, in Gangwon Province. Our approach involved virtually installing a sand storage tank under the existing water source to perform modeling in consideration of the current water intake and calculating the amount of water that can be taken from the sand dam. When the sand dam was applied at a size four times larger than the existing water source, it was found that the groundwater drainage increased significantly with changes in water surface slope and hydraulic conductivity.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.351-351
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• 2021

저수지에 대한 비상대처계획수립은 최근 기상이변 등에 따른 대규모 호우가 빈번히 발생하고 있을 뿐만 아니라 세계 도처에서 대규모 지진 등으로 많은 인명과 재산 피해가 속출함에 따라 지진 및 이상홍수에 대한 저수지의 안정성 평가를 수행하고 저수지 지점에서 발생할 수 있는 천재지변 또는 예상치 못한 대규모 재해에 효율적으로 대처하기 위한 비상상황의 등급 및 위험수준을 체계적으로 판단하고 비상상황 가상 시나리오별 체계적 행동요령 및 대처계획을 수립하여 저수지 붕괴에 따른 대규모 홍수피해 예상지역 주민들의 신속한 대응으로 생명과 재산피해를 최소화하는데 목적이 있다. 현행 한국농어촌공사 및 지자체에서 수립하고 있는 30만 톤 이상 저수지에 대한 1차원 모형 기반의 EAP수립은 침수구역을 산정할 때 수치지도에 의한 단일 침수심 분석으로 실제 침수구역과는 많은 오류가 나타난다. 이는 침수구역 부정확에 따른 피해복구액 산정이 과다로 책정될 수 있고, 마지막으로 가장 중요한 비상대처계획 수립에 막대한 영향을 미친다. 이에 본 연구는 댐 붕괴에 대응하기 위한 EAP 수립 시 기본이 되는 홍수범람해석을 수행하고 1차원 및 2차원 모형의 결과검토를 통해 보다 효과적인 비상대처계획의 수립을 위한 방안을 제시하고자 하였다. 이를 위해 경천저수지 유역을 대상으로 가능최대강수량 조건 하에서 가능최대홍수량을 산정하고 DAMBRK 모형을 이용하여 댐 붕괴 모의를 위한 시나리오 구성 및 모의를 수행하였다. 이후 댐 붕괴 모의결과를 이용하여 WMS(Watershed Modeling System) 모형을 이용한 1차원 홍수범람해석과 FLUMEN(FLUvial Modeling ENgine) 모형을 이용한 2차원 홍수범람해석에 적용 후 각 결과를 비교·검토하였다.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.105-119
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• 2023

Water supply is decreasing due to climate change, and coastal and island regions are highly dependent on groundwater, reducing the amount of available water. For sustainable water supply in coastal and island regions, it is necessary to accurately diagnose the current condition and efficiently distribute and manage water. For a precise analysis of the groundwater flow in the coastal island region, submarine fresh groundwater discharge was calculated for the Seongsan basin in the eastern part of Jeju Island. Two methods were used to estimate the thickness of the fresh groundwater. One method employed vertical interpolation of measured electrical conductivity in a multi depth monitoring well; the other used theoretical Ghyben-Herzberg ratio. The value using the Ghyben-Herzberg ratio makes it impossible to accurately estimate the changing salt-saltwater interface, and the value analyzed by electrical conductivity can represent the current state of the freshwater-saltwater interface. Observed parameter was distributed on a virtual grid. The average of submarine fresh groundwater discharge fluxes for the virtual grid was determined as the watershed's representative flux. The submarine fresh groundwater discharge and flux distribution by year were also calculated at the basin scale. The method using electrical conductivity estimated the submarine fresh groundwater discharge from 2018 to 2020 to be 6.27 × 10⁶ m³/year; the method using the Ghyben-Herzberg ratio estimated a discharge of 10.87 × 10⁶ m³/year. The results presented in this study can be used as basis data for policies that determine sustainable water supply by using precise water budget analysis in coastal and island areas.

• The Journal of Society for e-Business Studies
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• v.20 no.4
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• pp.1-17
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• 2015

A river water level monitoring system which prevents salt water damages and effectively excludes floods has been developed to contribute efficient operation of Nakdong river estuary barrage. The system can be used for monitoring upstream conditions more quickly and do appropriate responses over changes. Telemetry and telecontrols using PLCs have been built at the three sites that directly influence on the operation of barrage gates, and are linked to Nakdong river estuary barrage's IOS (Integrated Operation System) through public communication networks. By using PLC, the system can achieve even higher reliability and versatility than before as well as easy management. By power control devices, we can remotely control the power of PLCs to treat the minor troubles instantly without going on-sites. The power control devices also save data in preparation for the cases of communication failures. The system uses ADSL (FTTH) as a main network between SCADA server and PLCs, and CDMA (M2M) as a secondary network. In order to compensate security vulnerabilities of public communication network, we have installed the VPNs for secure communication between center and the observation stations, just like a dedicated network. Generally, river water level observations have been used custom-manufactured remote terminals to suit their special goals. However, in this case, we have established a system with open architecture considering the interface between different systems, the ease of use and maintenance, security, price, etc.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1068-1072
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• 2005

조석이란, 해면의 완만한 주기적 승강을 말하며, 보통 그 승강은 1일 약 2회이나, 곳에 따라서는 1일 1회의 곳도 있다. 조석에 있어서는 이 밖에 수일의 주기를 갖는 약간 불규칙한 승강, 반년, 또는 1년을 주기로 하는 다소 규칙적인 승강까지 포함하여 취급한다. 그러나, 각 항만마다 갖는 특정적인 주기인 수분내지 수십분의 주기의 승강은 조석으로 취급하지 않는다. 조석은 해양의 제현상 중에서 예측가능성이 가장 큰 현장으로 이는 조석이 천체의 운행과 연관되기 때문이다. 조석이란 지구로부터 일정한 거리에서 각 고유의 속도를 가지는 적도상을 운행하는 무수의 가상천체에 기인하는 규칙적인 개개의 조석을 합성한 것이며 이 개개의 조석을 분조(Constituent)라 한다. 여기에서 사용되는 신경망 모형은 입력과 출력으로 구성되는 블랙박스 모형으로서 하나의 시스템을 병렬적으로 비선형적으로 구축할 수 있다는 장점 때문에 과거 하천유역의 강우-유출과정에서의 경우 유출현상을 해석하고 유출과정을 모형화 하기 위해 사용하였다. 본 연구에서는 기존의 조위 예측방법인 조화분석법이 아닌 인공신경망을 이용하여 조위예측을 실시하였다. 학습이라는 최적화 과정을 통해 구조와 기능이 복잡한 자연현상을 그대로 받아들여 축적시킴으로써 이를 지식으로 현상에 대한 재현능력이 뛰어나고, 또한 신경회로망의 연상기억능력에 적용하여 수학적으로 표현이 불가능한 불확실한 조위곡선에 적용하기에 유리한 장점을 가지고 있다. 본 연구의 목적은 과거 조위이론을 통해 이루었던 조위예측을 우리가 알기 쉬운 여러 기후인자(해면기압, 풍향, 풍속, 음력 등)에 따른 조위곡선을 예측하기 위해 신경망 모형을 이용하여 여수지역의 조위에 적용하여 비교 분석하고자 한다. May가 제안한 공식을 더 확장하여 적용할 수 있는 실험 공식으로 개선하였으며 다양한 조건에 대한 실험을 수행하여 보다 정밀한 공식으로 개선할 수 있었다.$10,924m^3/s$ 및 $10,075m^3/s$로서 실험 I의 $2,757m^3/s$에 비해 통수능이 많이 개선되었음을 알 수 있다.함을 알 수 있다. 상수관로 설계 기준에서는 관로내 수압을 $1.5\~4.0kg/cm^2$으로 나타내고 있는데 $6kg/cm^2$보다 과수압을 나타내는 경우가 $100\%$로 밸브를 개방하였을 때보다 $60\%,\;80\%$ 개방하였을 때가 더 빈번히 발생하고 있으므로 대상지역의 밸브 개폐는 $100\%$ 개방하는 것이 선계기준에 적합한 것으로 나타났다. 밸브 개폐에 따른 수압 변화를 모의한 결과 밸브 개폐도를 적절히 유지하여 필요수량의 확보 및 누수방지대책에 활용할 수 있을 것으로 판단된다.8R(mm)(r^2=0.84)$로 지수적으로 증가하는 경향을 나타내었다. 유거수량은 토성별로 양토를 1.0으로 기준할 때 사양토가 0.86으로 가장 작았고, 식양토 1.09, 식토 1.15로 평가되어 침투수에 비해 토성별 차이가 크게 나타났다. 이는 토성이 세립질일 수록 유거수의 저항이 작기 때문으로 생각된다. 경사에 따라서는 경사도가 증가할수록 증가하였으며 $10\% 경사일 때를 기준으로 $Ro(mm)=Ro_{10}{\times}0.797{\times}e^{-0.021s(\%)}$로 나타났다.천성 승모판 폐쇄 부전등을 초래하는 심각한 선