• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.348-351
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• 2012

4대강 살리기 사업 등 대형 사업의 건설 및 시행에 의한 환경적 영향에 대한 예측과 적절한 수질관리 대안을 마련하기 위해서는 적절한 수문 수질모델을 이용하는 것이 필수적이며, 국내 대형 국책 사업 또는 중요 환경영향평가에서는 계속적으로 수질모델이 사용되고 그 적용 범위는 더욱 증가 될 전망이다. 따라서 이들 수질 모델의 사용에 있어서 예측의 정확도 및 신뢰도를 제고하는 것은 매우 중요한 일이라 할 수 있을 것이다. 특히 4대강 살리기 사업에 의해 다수의 보가 하천 내에 건설되고 준설이 실시됨에 따라 하천 내의 수리 동역학적 특성 및 수질특성이 변화할 것으로 예상되며, 적절한 수질관리 대책을 수립하기 위해서는 사업에 의한 수리 및 수질 특성 변화를 예측하고 시나리오를 분석할 있는 모델링 시스템을 구축하는 것이 필수적이다. 따라서 본 논문에서는 보 건설에 따른 다양한 수리 및 수질 특성 변화를 예측하기 위해 모의 가능 모형들을 조사하고, 국 내외 적용사례 분석을 통해서 현재 가장 많이 적용되고 있는 모형들을 선별하였다. 이를 토대로 모형 별 성능을 비교 분석하여 모형별 적용성을 검토하였다. 검토결과 신설보 설치에 따른 하천 수리 특성의 변화, 부유물질 및 동반 오염물질에 의한 수질 변화 등의 고려가 가능하며, 동적상태 모형으로 하천에서의 불연속적인 흐름에 따른 모의, 수심방향으로의 모의가 가능한 EFDC 모형이 보 설치에 따른 국부적인 영향을 자세하게 파악하는데 가장 적절한 모형으로 파악되었다.

• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.641-655
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• 1998

The methods of development and application of an expert system are suggested to solve more efficiently the problems of water resources and quality induced by the rapid urbanization. Major parameters of the water quantity and quality of urban areas are selected their characteristics are presented by the sensitivity analysis. The rules to decide the parameters effectively are proposed based on these characteristics. the ESPE(Expert System for Parameter Estimation), an expert system based on the 'facts' and 'rules', is developed using the CLIPS 6.0 and applied to the basin of the An-Yang stream. The results of estimating t도 parameters of water quantity show a high applicability, but those of water quality imply the necessity of improving the present methods due to both the complexity of estimation processes and the lack of decision rules.

• Journal of Korea Water Resources Association
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• v.42 no.12
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• pp.1039-1052
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• 2009

Radar measurement with high temporal and spatial resolutions can be a valuable source of data, especially in the areas where rain gauge installment is not practical. However, this kind of data brings with it many errors. The objective of this paper is to propose a method to evaluate statistically the quantitative and qualitative accuracy at different radar ranges, temporal intervals and raingage densities and use a bias adjustment technique to improve the quality of radar rainfall for the purpose of hydrological application. The method is tested with the data of 2 storm events collected at Jindo (S band) and Kwanak (C band) radar stations. The obtained results show that the accuracy of radar rainfall estimation increases when time interval rises. Radar data at the shorter range seems to be more accurate than the further one, especially for C-band radar. Using the Monte Carlo simulation experiment, we find out that the sampling error of the bias between radar and gauge rainfall reduces nonlinearly with increasing raingage density. The accuracy can be improved considerably if the real-time bias adjustment is applied, making adjusted radar rainfall to be adequately good to apply for hydrological application.

• Journal of Korea Water Resources Association
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• v.36 no.1
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• pp.117-128
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• 2003

The objectives of this study are to develop the total maximum daily loads simulation system, TOLOS that is capable of estimating annual nonpoint source pollution from small watersheds, to monitor the hydrology and water quality of the Balkan HP#6 watershed, and to validate TOLOS with the field data. TOLOS consists of three subsystems: the input data processor based on a geographic information system, the models, and the post processor. Land use pattern at the tested watershed was classified from the Landsat TM data using the artificial neutral network model that adopts an error back propagation algorithm. Paddy field components were added to SWAT model to simulate water balance at irrigated paddy blocks. SWAT model parameters were obtained from the GIS data base, and additional parameters calibrated with field data. TOLOS was then tested with ungauged conditions. The simulated runoff was reasonably good as compared with the observed data. And simulated water quality parameters appear to be reasonably comparable to the field data.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.3
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• pp.13-22
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• 2008

The objective of this study is to evaluate the applicability of extracted PRMS input parameters by KGIS-Hydrology over Yongdam-Dam watershed. KGIS-Hydrology is a system for automatic extraction and analysis of watershed characteristic data. Input parameters of PRMS were generated from GIS data (DEM, soil, forest type, etc.) using KGIS-Hydrology. Multi-temporal meteorological data from Jangsu station of KMA (Korea Meteorological Administration) were used for all simulation periods. Input parameters of PRMS were optimized using observed runoff data of Yongdam-Dam station (1966-2001) and validated using observed runoff data of Yongdam-Dam station (2002-2006, Yongdam-Dam watershed). The results showed that the simulated flows were much closed to the observed flows of Yongdam-Dam (2002-2006) and Donghyang (2001-2004) station by 0.49~0.83 and 0.57~0.75 model efficiencies, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.3
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• pp.303-314
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• 2024

Precipitation data are an integral part of water management planning, especially the design of hydroelectric structures and the study of floods and droughts. However, it is difficult to obtain accurate data due to space-time constraints. The recent increase in hydrological variability due to climate change has further emphasized the importance of precipitation simulation techniques. Therefore, in this study, the Modified Bartlett-Lewis Rectangular Pulse model was utilized to apply the parameters necessary to predict daily precipitation. The effect of this parameter on the daily precipitation prediction was analyzed by applying exponential distribution, Gamma distribution, and Weibull distribution to evaluate the suitability of daily precipitation prediction according to each distribution type. As a result, it is judged that parameters should be selected in consideration of regional and seasonal characteristics when simulating precipitation using the MBLRP model.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.205-205
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• 2012

국내에서 새로운 댐 저수지 건설을 통한 수자원의 안정적인 확보는 어려운 여건에 있다. 따라서 수자원의 효율적인 확보, 댐 하류하천의 수질 개선, 신규댐 건설 대체 효과를 기대하기 위해 기존 댐 저수지의 연계운영이 중요하게 인식되고 있다. 본 연구에서는 다수의 댐 저수지 수체를 연계하여 모델을 통해 해석하고자 안동-임하호를 연결한 2차원 모델(CE-QUAL-W2)을 구축하고, 2002년과 2006년 수문사상을 재현하였으며, 수리해석을 실시하였다. 안동호의 좌안인 임동면 마리와 임하호의 우안인 망천리를 연결하고, EL. 140 m 위치에 길이 2 km, 직경 5.5 m로 콘크리트 터널을 연결하는 것으로 가정하였다. 관내 바닥 마찰계수와 미소 마찰손실 값은 0.05를 입력하였다. 저수지 실측수위와 모의수위를 시계열로 비교한 결과, 2002년과 2006년 안동호와 임하호에서 여름철 유입량 증가에 따른 수위 상승을 잘 반영하였고, 결정계수값($R^2$)이 모두 0.9953 이상으로 나타나 모델은 두 저수지 물수지 계산에 있어서 높은 신뢰도를 보였다. 2006년을 대상으로 안동호와 임하호의 댐 앞에서 수심별 수온의 실측값과 모의값을 비교한 결과, 안동호는 4월부터 성층이 진행되어 5월에 수온약층이 EL. 130 m에 형성되었다. 7월 홍수가 중층 밀도류를 형성하여 수온 성층구조를 교란하였고, 기존의 수온약층이 EL. 120 m 로 하강하였으며, 표층 EL. 145 m에 새로운 수온약층이 형성되는 2단 성층 구조를 보였다. 여름철 동안 이러한 현상은 지속되었고, 10월부터 대기기온 강하와 함께 수직혼합이 시작되었다. 수온예측 오차는 AME $0.336{\sim}1.806^{\circ}C$, RMSE $0.415{\sim}2.271^{\circ}C$의 범위로 실측값을 잘 반영하는 것으로 나타났다. 임하호도 안동호와 유사한 경향을 보였고, 모델은 두 저수지에서 전 기간에 걸쳐 모두 안정적으로 저수지 수온 성층현상을 모의하였다. 2002년 수문사상에서 안동-임하 연계 운영시 안동호의 평균 수위는 1.38 m 상승하였고, 임하호는 3.75 m 낮아지는 것으로 모의되었다. 수위변동에 따른 유동 유량은 임하호에서 안동호로 3억 6천 4백만 톤, 안동호에서 임하호로 2억 9천 1백만 톤으로 임하호에서 안동호로 유동한 유량이 높게 나타났다. 유역면적에 비해 저수용량이 작은 임하호의 경우 두 저수지간 유량의 이동에 따라서 저수용량의 증가로 인한 홍수 저감 효과가 있을 것으로 판단된다. 반면, 안동-임하 연계 운영시 임하호의 차가운 물이 안동호로 유입되는 경우, 안동호의 수온 성층구조에 영향을 주었다. 안동호의 경우는 단독운영시보다 높은 위치에 수온약층(EL. 140 m)이 형성되었으며, 임하호는 반대로 저수위가 낮아지면서 단독운영시보다 수온약층의 위치가 약간 낮아졌다. 이러한 결과는 두 저수지 연결시 안동호의 탁수와 수질 환경에 변화가 있을 수 있음을 시사한다.

• Journal of the Korean GEO-environmental Society
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• v.25 no.9
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• pp.5-14
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• 2024

In Korea, torrential rain frequency and intensity have surged over the past five years (2019-2023), breaking rainfall records. Due to insufficient observation facilities for rainfall and runoff data in small mountainous catchments, preparing for unexpected floods is challenging. This study examines the Bidogyo catchment in Goesan-gun, Chungcheongbuk-do, comparing design flood discharge calculated with optimized parameters versus standard guidelines. Using HEC-HMS and Q-GIS for model construction, five rainfall events were analyzed with data from the National Water Resources Management Information System. The time of concentration (Tc) and storage constant (K) were calculated using the Seokyeongdae formula and model optimization. Results showed that optimized parameters produced higher objective function values for flood events. The design flood discharge varied by -10.7% to 17.3% from the standard guidelines when using optimized parameters. Moreover, optimized parameters yielded flood discharges closer to observed values, highlighting limitations of the Seokyeongdae formula for all catchments. Further research aims to develop suitable parameter estimation methods for small mountainous catchments in Korea.

• Journal of Korea Water Resources Association
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• v.40 no.6 s.179
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• pp.447-458
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• 2007

In this study, the coastal urban flood prediction and warning system based on HEC-RAS and SWMM were investigated to evaluate a watershed of On-Cheon stream in Busan which has characteristics of costal area cased by flooding of coastal urban areas. The basis of this study is a selection of various geological data from the numerical map that is a watershed of On-Cheon stream and computation of hydrologic GIS data. Thiessen method was used for analyzing of rainfall on the On-Cheon stream and 6th regression equation, which is Huff's Type II was time-distribution of rainfall. To evaluate the deployment of flood prediction and warning system, risk depth was used on the 3 selected areas. To find the threshold runoff for hydraulic analysis of stream, HEC-RAS was used and flood depth and threshold runoff was considered with the effect of tidal water level. To estimate urban flash flood trigger rainfall, PCSWMM 2002 was introduced for hydrologic analysis. Consequently, not only were the criteria of coastal urban flood prediction and warning system decided on the watershed of On-Cheon stream, but also the deployment flow charts of flood prediction and warning system and operation system was evaluated. This study indicates the criteria of flood prediction and warning system on the coastal areas and modeling methods with application of ArcView GIS, HEC-RAS and SWMM on the basin. For the future, flood prediction and warning system should be considered and developed to various basin cases to reduce natural flood disasters in coastal urban area.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.408-412
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• 2006

Growing needs for efficient management of water resources urge integrated management of whole basin. As one of the tools for supporting above tasks, this study aims to indicate a hydrologic model that can simulate the streamflow discharges at some control points located both upper and down stream of dams. For the development and utilization of non analysis model, relevant basin information including historical precipitation and river water stage data, geophysical basin characteristics, and water intake and consumptions needs to be collected and stored into the hydrologic database of Integrated Real-Time Water Information System. The well-known SSARR model was selected for basis of continuous daily runoff model for forecasting short and long-term national river flows in this paper.