• 한국수자원학회논문집
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• 제36권5호
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• pp.851-861
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• 2003

적설 및 융설모의를 포함하여 소양강댐과 충주댐에 대한 유출모의를 수행하였다. 사용한 모의모형은 탱크모형의 수정 형태로서 직렬 3단 탱크와 맥동 응답함수로 이루어져 있다. 매개변수의 추정에는 컴플렉스 혼합진화 (SCE-UA) 전역최적화 기법을 사용하였다. 적설 및 융설모의를 위하여 유역을 고도별로 4개 영역으로 구분하였으며 고도에 따른 기온감률은 0.6$^{\circ}C$/100m로 하였다. 모의 결과 12∼2월 사이에 이 지역에 내리는 강수는 대부분 눈으로 쌓여 있다가3∼4월에 녹아서 유출되었다. 소양강댐의 3∼4월 평균 유출량은, 융설모의를 하는 경우가 하지않는 경우에 비하여 관측 유출량의 약 1/5이 증가되었다. 충주댐의 경우는 융설 모의로 인하여 관측 평균 유출량의 약 1/4에 이르는 유출량이 증가되었다. 그렇지만 두 댐 모두, 융설을 포함하여 유출을 모의하 였음께도 불구하고, 모의 유출량이 관측 유출량보다 작았다.

• 한국습지학회지
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• 제11권3호
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• pp.161-169
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• 2009

도시 지역의 강우-유출 과정은 자연유역과 비교하여 보다 복잡한 형태를 지니고 있다. 도심의 확장과 개발로 인해 유역의 특성들이 변화하고, 이로 인해 유출 모형의 적용 또한 어렵다. 본 연구에서는 전주의 대표적인 도시하천인 조경천 유역을 대상으로 도시화의 진행에 따른 수문환경의 변화와 강우-유출 형태의 변화를 분석하였다. 도시화 정도에 따라 도시화가 진행되기 전인 자연유역기(1924), 전북대학교 조성기(1963), 주거단지 조성기(1986), 도시화 완료기(1995)로 단계를 구분하고, 각 단계별 유역특성자료와 불투수면적 등의 입력자료를 기반으로 SWMM 모형을 이용하여 유출을 분석하였다. 단계별 배수계통도에 의하면, 유로연장, 조도계수, 지표면 저류계수는 감소하였고, 토지이용 상태는 투수면적이 97.7%에서 42%로 감소하였고, 불투수 면적은 0.6%에서 34.0%로 증가하였다. 도달시간은 90분에서 37분으로 감소하였고, 첨두유량은 $4.37m^3/s$에서 $111.13m^3/s$로 증가 하였으며, 유출률은 0.8%에서 68%로 증가하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.233-233
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• 2015

Vu Gia - Thu Bon basin is located in central Vietnam between Truong Son mountain range on the border with Lao in the west and the East Sea in the east. The basin occupies about 10,350 km2 or roughly 90% of the Quang Nam Province and includes Da Nang, a very large city with about 876,000 inhabitants. Total annual rainfall ranges from about 2,000 mm in central and downstream areas to more than 4,000 mm in southern mountainous areas. Rainfall during the monsoon season accounts for 65 to 80% of total annual rainfall. The highest amount of rainfall occurs in October and November which accounts for 40 to 50% of the annual rainfall. Rainfall in the dry season represents about 20 to 35% of the total annual rainfall. The low rainfall season usually occurs from February to April, accounting for only 3 to 5% of the total annual rainfall. The mean annual flow volume in the basin is $19.1{\times}109m 3$. Similar to the distribution of rainfall, annual flows are distinguished by two distinct seasons (the flood season and the low-flow season). The flood season commonly starts in the mid-September and ends in early January. Flows during the flood season account for 62 to 69% of the total annual water volume, while flows in the dry season comprise 22 to 38% of total annual run-off. The water volume gauged in November, the highest flow month, accounts for 26 to 31% of the total annual run-off while the driest period is April with flows of 2 to 3% of the total annual run-off. There are some hydropower projects in the Vu Gia - Thu Bon basin as the cascade of Song Bung 2, Song Bung 4, and Song Bung 5, the A Vuong project currently under construction, the Dak Mi 1 and Dak Mi 4 projects on the Khai tributary, and the Song Con project on the Con River. Both the Khai tributary and the Song Con join the Bung River downstream of SB5, although the Dak Mi 4 project involves an inter-basin diversion to Thu Bon. Much attention has recently been focused on the effects that climate variability and human activities have had on runoff. In this study, data from the Vu Gia - Thu Bon River Basin in the central of Viet Nam were analyzed to investigate changes in annual runoff during the period of 1977-2010. The nonparametric Mann-Kendall test and the Mann-Kendall-Sneyers test were used to identify trend and step change point in the annual runoff. It was found that the basin had a significant increasing trend in annual runoff. The hydrologic sensitivity analysis method was employed to evaluate the effects of climate variability and human activities on mean annual runoff for the human-induced period based on precipitation and potential evapotranspiration. This study quantitatively distinguishes the effects between climate variability and human activities on runoff, which can do duty for a reference for regional water resources assessment and management.

• 한국물환경학회지
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• 제28권1호
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• pp.1-9
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• 2012

It has been known that Golf course could impose negative impacts on water-ecosystem if pollutant-laden runoff is not treated well. It is important to control non-point source and re-use treated wastewater from the golf course to secure water quality of receiving waterbodies. At golf courses, the rainfall-runoff is affected by various practices to manage grasses. In many hydrological modelings, especially in simple rainfall-runoff modeling, effects on runoff of plant growth and cutting are not considered. In the study, the water erosion prediction project (WEPP), capable of simulating plant growth and various management, was evaluated for its runoff prediction from golf course under grass cutting and irrigation. The %Difference, $R^2$ and the NSE for runoff comparisons were 1.15%, 0.93 and 0.92 for calibration, and 18.12%, 0.82 and 0.88 for validation period, respectively. In grass cutting scenario, grass height was managed to be 18~25 mm. The estimated runoff was decreased by 27%. The difference in estimated total runoff was 11.8% depending on irrigation. As shown in this study, if grass management and irrigation are well-controlled, water quality of downstream areas could be obtained.

• 한국물환경학회지
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• 제30권1호
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• pp.8-15
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• 2014

In this study, regression equation was analyzed to estimate non-point source (NPS) pollutant loads in orchard area. Many factors affecting the runoff of NPS pollutant as precipitation, storm duration time, antecedent dry weather period, total runoff density, average storm intensity and average runoff intensity were used as independent variables, NPS pollutant was used as a dependent variable to estimate multiple regression equation. Based on the real measurement data from 2008 to 2012, we performed correlation analysis among the environmental variables related to the rainfall NPS pollutant runoff. Significance test was confirmed that T-P ($R^2=0.89$) and BOD ($R^2=0.79$) showed the highest similarity with the estimated regression equations according to the NPS pollutant followed by SS and T-N with good similarity ($R^2$ >0.5). In the case of regression equation to estimate the NPS pollutant loads, regression equations of multiplied independent variables by exponential function and the logarithmic function model represented optimum with the experimented value.

• Current Research on Agriculture and Life Sciences
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• 제32권3호
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• pp.135-143
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• 2014

The variability and temporal trends of the annual and seasonal minimum and maximum temperature, rainfall, relative humidity, wind speed, sunshine hours, and runoff were analyzed for 5 major rivers in Korea from 1960 to 2010. A simple regression and non-parametric methods (Mann-Kendall test and Sen's estimator) were used in this study. The analysis results show that the minimum temperature ($T_{min}$) had a higher increasing trend than the maximum temperature ($T_{max}$), and the average temperature increased by about $0.03^{\circ}C\;yr.^{-1}$. The relative humidity and wind speed decreased by $0.02%\;yr^{-1}$ and $0.01m\;s^{-1}yr^{-1}$, respectively. With the exception of the Han River basin, the regression analysis and Mann-Kendall and Sen results failed to detect trends for the runoff and rainfall over the study period. Rapid land use changes were linked to the increase in the runoff in the Han River basin. The sensitivity of the evapotranspiration and ultimately the runoff to the meteorological variables was in the order of relative humidity > sunshine duration > wind speed > $T_{max}$ > $T_{min}$. Future studies should investigate the interaction of the variables analyzed herein, and their relative contributions to the runoff trends.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.235-235
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• 2015

This study investigates the impact of event characteristics on runoff dynamics during extreme flood events observed in a $8.5km^2$ experimental watershed located in South Korea. The 37 most extreme flood events with event rainfall in excess of 50 mm were analysed using an event-based rainfall-runoff model; the Revitalised Flood Hydrograph (ReFH) routinely used for design flood estimation in the United Kingdom. The ReFH model was fitted to each event in turn, and links were investigated between each of the two model parameters controlling runoff production and response time, respectively, and event characteristics such as rainfall depth, duration, intensity and also antecedent soil moisture. The results show that the structure of the ReFH model can effectively accommodate any nonlinearity in runoff production, but that the linear unit hydrograph fails to adequately represent a reduction in watershed response time observed for the more extreme events. By linking the unit hydrograph shape directly to rainfall depth, the consequence of the observed nonlinearity in response time is to increase design peak flow by between 50% for a 10 year return period, and up to 80% when considering the probable maximum flood (PMF).

• 한국농공학회논문집
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• 제51권6호
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• pp.11-16
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• 2009

This study is to suggest the SWAT model as inputs for the estimation of CN (Curve number) if we do not have hourly rainfall and runoff data in the ungaged watershed. The daily CNs were estimated by using SWAT model for Chungju dam watershed and the CNs by hourly rainfall and runoff data in the same period with daily CN estimation were also estimated. Then the daily and hourly CNs were compared each other. The CNs by SWAT model were larger than the actual CNs. 7.4% larger in AMC-I, 1.2% in AMC-II, and 6.3% in AMC-III respectively. If we consider various uncertainties in the estimation of CN, the error of 6.8% could be acceptable for the application in the field.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.753-758
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• 1999

Concentration and discharge have been intensively monitored at the drainage canal in a paddy field area during storm-periods. Among 4 storm runoffs, the No. 2 and No. 3 runoff was in the fertilizer application period. The specific load-specific discharge equation L=aQ\ulcorner have different characteristics for the pollutants. The coefficient of b generally shows values of more than 1 for T-N, about 1 for COD\ulcorner, and less than 1 for T-P. For same specific discharge, No. 2 runoff shows higher specific load than other runoffs. For the coefficient of determination of the L-Q equation, COD\ulcorner is higher than T-N and T-P. The mean concentration of direct runoff, significantly depending on the storm events, is 0.6 to 8.3mg/ιfor T-N, 0.05 to 0.51 mg/ι for T-P, and 10.0 to 18.3 mg/ι for COD\ulcorner.

• 한국지형학회지
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• 제15권2호
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• pp.37-53
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• 2008

본 연구는 장기적인 기상 자료(meterological data)와 하천 유출량 자료(stream run off data)의 획득이 가능한 충청도 병천천 유역에 대해 BROOK90 4.4e 물리 결정 물 수지 모델(physical deterministic water balance model)을 사용하여 '병천천 유역의 물 수지 모델'을 수립한 것이다. 모델 조작 매개변수(model fitting parameter)를 교정(calibration)한 비준 모델(validation model)을 가지고 기상 자료(meterological data)가 있지만 하천 유출량 자료(stream runoff data)는 없는 시기에 대한 장기적인 물 수지를 수립하였다. 연구의 결과는 a priori 모의 단계에서 실측 하천 유출량(measured stream runoff data)과 모의 하천 유출량(simulated stream runoff data)이 유사하게 나옴으로써 물 수지 모의 실험(experiment for water balance modeling)이라는 연구 성격으로서 목표하는 첫 번째 기대 수준에 도달하고 있다. 모델 조작 매개변수(model fitting parameter)를 확정하고 수행한 비준 모의(validated simulation)를 통해 과거 9년(1998년 ~ 2006년)의 물 수지가 복원되었다. 이 유역의 지형(geomophology), 식생(vegetation), 토양(soil), 토지이용(land use) 상황이 변하지 않는다면 기상자료(meterological data)만 가지고서 언제나 하천 유출량(stream runoff amount), 토양수량(siol water amount) 그리고 증발산량(evapotranspiration) 등 다양한 수문기후 자료를 생산할 수 있다. 이 연구는 현재 한국의 물 수지(water balance) 수립은 물론이고 과거의 물 수지 복원(water balance reconstruction) 분야에 또 하나 새로운 지평을 열었다. 이러한 연구 결과는 한반도에서의 기후(climate)와 식생(vegetation)의 변화에 따른 미래 물 수지(water balance) 예측 분야에서도 널리 활용할 수 있을 것이다.