• 한국농공학회논문집
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• 제55권2호
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• pp.47-57
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• 2013

This study is to assess the reduction of non-point source pollution loads for rice straw mulching of upland crop cultivation at a watershed scale. For Byulmi-cheon watershed (1.21 $km^2$) located in the upstream of Gyeongan-cheon, the HSPF (Hydrological Simulation Program-Fortran) and SWAT (Soil and Water Assesment Tool), physically based distributed hydrological models were applied. Before evaluation, the model was calibrated and validated using 9 rainfall events. The Nash-Sutcliffe model efficiency (NSE) for streamflow using the HSPF was 0.62~0.76 and the determination coefficient ($R^2$) for water quality (sediment, total nitrogen T-N, and total phosphorus T-P) were 0.72, 0.62, and 0.63 respectively. The NSE for streamflow using the SWAT were 0.43~0.81 and the $R^2$ for water quality (sediment, T-N, and T-P) were 0.54, 0.87, and 0.64 respectively. From the field experiment of 16 rainfall events, the rice straw cover condition reduced surface runoff average 10.0 % compared to normal surface condition. By handling infiltration capacity (INFILT) in HSPF model, the value of 16.0 mm/hr was found to reduce about 10.0 % reduction of surface runoff. For this condition, the reduction effect of sediment, T-N, and T-P loads were 87.2, 28.5, and 85.1 % respectively. By handling soil hydraulic conductivity (SOL_K) in SWAT model, the value of 111.2 mm/hr was found to reduce about 10.0 point reduction of surface runoff. For this condition, the reduction effect of sediment, T-N, and T-P loads were 80.0, 83.2, and 78.7 % respectively. The rice straw surface covering was effective for removing surface runoff dependent loads such as sediment and T-P.

• 한국수자원학회논문집
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• 제47권10호
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• pp.935-943
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• 2014

정규식생지수 (Normalized Difference Vegetation Index)는 각종 수문모델, 지표-대기 모델에 입력 자료로 사용되는 인자로 대기와 지표 사이의 에너지 교환 및 수문기상학적인자의 변동성을 파악하는데 매우 중요하다. 이에따라, 식생고유의 분광반사 특성을 이용하여 인공위성으로 관측하는 NDVI 값의 정확한 모의를 위한 연구가 진행되고 있다. 본 연구에서는 국내 최초의 정지궤도위성인 Communication, Ocean and Meteorological Satellite (COMS)에서 산출된 정규식생지수의 적용성을 판단하기 위해 Maximum Value Composite (MVC) 방법을 활용하여 산정한 16일 단위, 8일 단위의 정규식생지수와 MODerate-resolution Imaging Spectro-radiometer (MODIS) 센서에서 관측된 정규식생지수와 비교 검증을 실시하였다. 그 결과 16일 단위와 8일 단위 NDVI 모두 좋은 결과를 나타내었다. 이러한 결과를 토대로 COMS의 활용 가능성을 확인할 수 있었으며 추후 수문 생태학적 연구에 중요한 자료로 사용될 수 있을 것이다.

• 한국수자원학회논문집
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• 제46권3호
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• pp.229-243
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• 2013

평창유역의 적설량을 모의하기 위하여 HSPF 모형을 적용하였다. 미래 적설량을 평가하기 위해 CIMIP3에서 제공하는 A1, A1B, B1의 온실가스 배출시나리오에 기반한 GCMs를 이용하였으며, HSPF 모형과 GCMs의 통계학적 오류를 최소화 하기 위해 편의보정(Bias-correction)과 시간적 분해모형(Temporal disaggregation)을 적용하였다. 모형의 검 보정 결과 모의된 유출량과 적설량의 경우 모형 효율이 높게 나타났으며, 특히 모형의 검정 후 상관계수를 분석한 결과 월별 유출량의 상관계수는 0.94로 나타났다. 월별 적설량, 또한, 상관계수가 0.91로 나타나 보정된 HSPF 모형이 평창지역에 대한 유출량과 적설량을 잘 모의하고 있는 것으로 판단된다. GCMs를 이용한 2018년 평창올림픽 경기장의 적설량을 분석한 결과 1월에는 17.62%, 2월에는 9.38%, 3월에는 7.25%의 적설량이 감소되는 것으로 나타났다.

• 한국측량학회지
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• 제8권2호
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• pp.9-16
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• 1990

본 논문은 해안에 건설된 해안 구조물에 의한 해안선 번형에 관한 연구이다. 해안선 변형을 예측하는 방법에는 경험적인 방법, 수리모형방법 및 수치방법 등이 있다. 이 중에서 수치모형방법이 측지분야에서는 가장 적합하다. 예측 모델은 여러 가지가 있다. 본 연구는 수리학적 인자가 적고, 자연현상을 단순화 시킬 수 있는 해안선 모델을 채택하였다. 본 연구는 우선 이상적인 안벽 경계 조건을 설정하고, 동해안의 동산항에 개략 모델과 엄밀 모델을 적용하였다. 그 결과 해안선 변형 모델은 안벽의 최적 위치를 예측할 수 있었으며, 안벽은 파의 입사각이 20$^\circ$이하인 해안을 보호할 수 있었으며 파고와 쇄파대의 비는 해안선 변형에 영향을 미치지 않았다. 또한 엄밀 모델은 정확하나 장기 변형의 예측이 불가능하였고, 개략법은 그와 반대였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.188-188
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• 2017

Rainfall is an important input to hydrological models. The accuracy of hydrological studies for water resources and floods management depend primarily on the estimation of rainfall. Thailand is among the countries that have regularly affected by floods. Flood forecasting and warning are necessary to prevent or mitigate loss and damage. Merging near real time satellite-based precipitation estimation with relatively high spatial and temporal resolutions to ground gauged precipitation data could contribute to reducing uncertainty and increasing efficiency for flood forecasting application. This study tested the applicability of satellite-based rainfall for water resources management and flood forecasting. The objectives of the study are to assess uncertainty associated with satellite-based rainfall estimation, to perform bias correction for satellite-based rainfall products, and to evaluate the performance of the bias-corrected rainfall data for the prediction of flood events. This study was conducted using a case study of Thai catchments including the Chao Phraya, northeastern (Chi and Mun catchments), and the eastern catchments for the period of 2006-2015. Data used in the study included daily rainfall from ground gauges, telegauges, and near real time satellite-based rainfall products from TRMM, GSMaP and PERSIANN CCS. Uncertainty in satellite-based precipitation estimation was assessed using a set of indicators describing the capability to detect rainfall event and efficiency to capture rainfall pattern and amount. The results suggested that TRMM, GSMaP and PERSIANN CCS are potentially able to improve flood forecast especially after the process of bias correction. Recommendations for further study include extending the scope of the study from regional to national level, testing the model at finer spatial and temporal resolutions and assessing other bias correction methods.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.146-146
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• 2022

A flash flood is one of the most hazardous natural events caused by heavy rainfall in a short period of time in mountainous areas with steep slopes. Early warning of flash flood is vital to minimize damage, but challenges remain in the enhancing accuracy and reliability of flash flood forecasts. The forecasters can easily determine whether flash flood is occurred using the flash flood guidance (FFG) comparing to rainfall volume of the same duration. In terms of this, the hydrological model that can consider the basin characteristics in real time can increase the accuracy of flash flood forecasting. Also, the predicted radar rainfall has a strength for short-lead time can be useful for flash flood forecasting. Therefore, using both hydrological models and radar rainfall forecasts can improve the accuracy of flash flood forecasts. In this study, FFG was applied to simulate some flash flood events in the Taehwa river basin by using of SURR model to consider soil moisture, and applied to the flash flood forecasting using predicted radar rainfall. The hydrometeorological data are gathered from 2011 to 2021. Furthermore, radar rainfall is forecasted up to 6-hours has been used to forecast flash flood during heavy rain in August 2021, Wulsan area. The accuracy of the predicted rainfall is evaluated and the correlation between observed and predicted rainfall is analyzed for quantitative evaluation. The results show that with a short lead time (1-3hr) the result of forecast flash flood events was very close to collected information, but with a larger lead time big difference was observed. The results obtained from this study are expected to use for set up the emergency planning to prevent the damage of flash flood.

• 물과 미래
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• 제26권4호
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• pp.117-125
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• 1993

A flood -flow management system model of river basin has been developed in this study. The system model consists of the observation and telemetering system, the rainfall forecasting and data-bank system, the flood runoff simulation system, the dam operation simulation system, the flood forecasting simulation system and the flood warning system. The Multivariate model(MV) and Meterological-factor regression model(FR) for rainfall forecasting and the Streamflow synthesis and reservoir regulation(SSARR) model for flood runoff simulation have been adopted for the development of a new system model for flood-flow management. These models are calibrated to determine the optimal parameters on the basis of observed rainfall, streamflow and other hydrological data during the past flood periods. The flood-flow management system model with SSARR model(FFMM-SR,FFMM-SR(FR) and FFMM-SR(MV)), in which the integrated operation of dams and rainfall forecasting in the basin are considered, is then suggested and applied for flood-flow management and forecasting. The results of the simulations done at the base stations are analysed and were found to be more accurate and effective in the FFMM-SR and FFMM0-SR(MV).

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.138-142
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• 2005

The change of precipitation and temperature due to the global. warming eventually caused the variation of water availability in terms of potential evapotranspiration, soil moisture, and runoff. In this reason national long-term water resource planning should be considered the effect of climate change. Study of AOGCM-based scenario to proposed the plausible future states of the climate system has become increasingly important for hydrological impact assessment. Future climate changes over East Asia are projected from the coupled atmosphere-ocean general circulation model (AOGCM) simulations based on Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A2 and B2 scenarios using multi-model ensembles (MMEs) method (Min et al. 2004). MME method is used to reduce the uncertainty of individual models. However, the uncertainty increases are larger over the small area than the large area. It is demonstrated that the temperature increases is larger over continental area than oceanic area in the 21st century.

• Journal of the Korean Data and Information Science Society
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• 제24권2호
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• pp.401-408
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• 2013

Soil moisture is a very important variable in various area of hydrological processes. We predict the soil moisture using a support vector regression. The model is trained and tested using the soil moisture data observed in five sites in the Yongdam dam basin. With respect to soil moisture data of of four sites-Jucheon, Bugui, Sangieon and Ahncheon which are used to train the model, the correlation coefficient between the esimtates and the observed values is about 0.976. As the result of the application to Cheoncheon2 for validating the model, the correlation coefficient between the estimates and the observed values of soil moisture is about 0.835. We compare those results with those of artificial neural network models.

• 상하수도학회지
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• 제13권2호
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• pp.74-81
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• 1999

In this study, the hydrological changes due to urbanization were investigated and fundamental theory and characteristics of typical urban runoff model such as CHICAGO Model was studied. Above model was applied for urbanizing Dongsucheon basin, Incheon. The main parameters(CI, CP, CS) which are included in this model depending on runoff results were determined, and dimensionless values such as total runoff ratio($Q_{TR}$), peak runoff ratio($Q_{PR}$), and runoff sensitivity ratio($Q_{SR}=Q_{TR}/Q_{PR}$) were estimated in order to evaluate and compare the characteristics of model based on relative sensitivity analysis. Finally, applied model was proposed based on understanding of work types and established urban runoff models which can simulate well for areal development patterns and urban river basin.