• 물과 미래
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• 제9권2호
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• pp.76-86
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• 1976

The 30-year design flood hydrograph for the Musim Representative Basin, one of the study basins of the International Hydrological Program, is synthesized by the method of unit hydrograph. The theory of unit hydrograph has been well known for a long time. However, the synthesis of flood hydrograph by this method for a basin with insufficient hydrologic data is not an easy task and hence, assumptions and engineering judgement must be exercized. In this paper, the problems often encountered in applying the unit hydrograph method are exposed and solved in detail based on the theory and rational judgement. The probability rainfall for Cheonju Station is transposed to the Musim Basin since it has not been analyzed due to short period of rainfall record. The duration of design rainfall was estimated based on the time of concentration for the watershed. The effective rainfall was determined from the design rainfall using the SCS method which is commonly used for a small basin. The spatial distribution of significant storms was expressed as a dimensionless rainfall mass curve and hence, it was possible to determine the hyetograph of effective design storm. To synthesize the direct runoff hydrograph the 15-min. unit hydrograph was derived by the S-Curve method from the 1-hr unit hydrograph which was obtained from the observed rainfall and runoff data, and then it was applied to the design hyetograph. The exsisting maximum groundwater depletion curve was derived by the base flow seperation. Hence, the design flood hydrograph was obtained by superimposing the groundwater depletion curve to the computed direct runoff hydrograph resulting from the design storm.

• 대한토목학회논문집
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• 제33권4호
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• pp.1361-1375
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• 2013

Lee et al. (2011)이 제시한 목감천 유역의 하천복원 설계절차에 근거하여 수리구조물의 설계와 관련 있는 설계홍수량을 산정에 있어 비정상성을 고려하여 산정하였다. 본 연구의 목적은 목감천 유역에서 비정상성을 고려한 새로운 설계홍수량을 제안하기 위함이다. 설계홍수량 산정방법인 설계-호우단위도법과 직접 홍수빈도해석법을 적용하였으며, 각각의 방법에 사용되는 빈도분석은 NCAR (National Center for Atmospheric Research)에서 개발된 extRemes 모형을 통하여 비정상성을 고려하였다. 직접 홍수빈도해석의 방법은 유량으로부터 직접 빈도해석을 수행한다는 점에서 신뢰성이 기대되지만, 설계-호우단위도법보다 다소 과소 추정되었다. 따라서 가장 크게 산정된 설계호우-단위도법의 100년 빈도 설계홍수량을 목감천 유역의 설계홍수량으로 결정하였다.

• 물과 미래
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• 제14권4호
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• pp.27-34
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• 1981

The design flow of the urban strom drainage systems has been assessed largely on a basis of empirical relations between rainfall and runoff, and the rational formula has been widely used for the cities in our country. In order to estimate it more accurately, the urban runoff simulation model based on the RRl method has been developed and applied to the sample basin in this study. The rainfall hyetograph of the design stromfor the design flow has been obtained by the determination of the total rainfall and the temporal distributions of that rainfall. The total rainfall has been assessed from the empirical formula of rainfall intensity and the temporal distribution of that rainfall determined on the basis of Huff's method from the historical rainfall data of the basin. The virtual inflow hydrograph to each inlet of the basin has been constructed by computing the series of discharges in each time increment, using design strom hyetograph and time-area diagram. The actual runoff hydrograph at the basin outlet has been computed from the virtual inflow hydrographs by developing a relations between discharge and storage for the watershed. The discharge data for verification of the simulated runoff hydrograph are not available in the sample basin and so the sensitivity analysis of the simulation model has not been possible. The peak discharge for the design of drainage systems has been estimated from the computed runoff hydrograph at the basin outlet and compared to thatl obtained form the rational formula.

• 물과 미래
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• 제19권1호
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• pp.57-63
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• 1986

유역 추적에 자주 쓰이는 합성 단위 유량도 방법의 일종인 Snyder 방법에 있어서의 계수를 남한강 수계에서 재조정하는 과정을 제시하였다. 그 과정은, 과거의 조사에서 구한 남한강 수계의 Snyder 공식에서 초기값을 구한 다음, 이 값을 HEC-1 모델에 적용시켜 계수를 재조정한 후에 그 계수로부터 Snyder의 개선공식을 구하게 된다. 이와 같은 과정으로 구한 개선 공식은 기존 공식에 비해 계산 수문 곡선의 첨두 유량의 크기가 커지게 되며, 첨두 유량에 도달하는 기울기도 기존 공식보다 급격하게 되는 특성을 가지게 된다. 또한 첨두 유량이 발생하는 시간을 결정하여 주는 지체 시간이 기존 공식에 비해 개선 공식에서 작게 되기 때문에 첨두 유량이 발생되는 시간도 개선 공식을 사용하게 되면 기존 공식을 사용한 경우보다 더 빨라지게 된다.

• Korean Journal of Hydrosciences
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• 제3권
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• pp.97-104
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• 1992

To design the minor structures in the small watersheds, it is required to calculate the peak discharge. For these calculations the simple peak flow prediction equations, the unit hydrograph method. the syntheic unit hydrograph methods or the runoff simulation models are adopted. To use these methods it is generally requried to know the amount and the distributions of the design rainfall; which are the uniform distribution, the trangular distribution, the trapezoidal distribution, or the Huff type distribution. In this study, the peak discharges are calculated by the different rainfall distributions and the results are compared.

• 산업기술연구
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• 제3권
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• pp.95-101
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• 1983

This study aims at the determination of the coefficienties of runoff and infiltration affecting runoff. The rating curve is more available than the peak flood runoff to determine flood control plan of flood control reservoir and the volume of hydroelectric power plant, or to make multipurpose dam. In hydrologic analysis and design, it is necessary to develop relations between precipitation and runoff, possible using some of the factors affecting runoff as parameters. In order to calculate the runoff discharge, the runoff process constituting elements are divided to the surface runoff, the subsurface runoff and the groundwater runoff. By comparing the computed hydrograph with the measured hydrograph, determinned the watershed TANK Model constant Varying the tank model constant for approximating the computed hydrograph to the measured hydrograph.

• 한국수자원학회논문집
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• 제30권4호
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• pp.327-334
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• 1997

본 연구는 우리나라의 2개 하천지점에서 홍수 수문곡선 유도에 이용된 탱크모형의 매개변수를 검정하여 향후 상기 모형들이 관련 하천의 홍수예·경부에 직접 이용되도록 하는데 있다. 선정된 지점은 금강의 공주와 영산강의 나주지점이며 모형의 검정 결과 영산강의 겨우 영산강 유역개발 2단계 수문조사에서 유도된 모형의 매개변수가 비교적 타당하였으나 금강의 경우 대청 다목적댐 타당성 조사보고서에 수록된 모형의 매개변수에 10-1을 곱함으로서 실측치와 거의 일치하는 홍수 수문곡선을 얻을 수 있었다.

• 한국농공학회논문집
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• 제56권6호
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• pp.103-111
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• 2014

This study was to develop the flood analysis module (FAM) for implementation of a web-based real-time agricultural flood management system. The FAM was developed to apply for an individual watershed, including agricultural reservoir. This module calculates the flood inflow hydrograph to the reservoir using effective rainfall by NRCS-CN method and unit hydrograph calculated by Clark, SCS, and Nakayasu synthetic unit hydrograph methods, and then perform the reservoir routing by modified Puls method. It was programmed to consider the automatic reservoir operation method (AutoROM) based on flood control water level of reservoir. For a $15.7km^2$ Gyeryong watershed including $472{\times}10^4m^3$ agricultural reservoir, rainfall loss, rainfall excess, peak inflow, total inflow, maximum discharge, and maximum water level for each duration time were compared between the FAM and HEC-HMS (applied SCS and Clark unit hydrograph methods). The FAM results showed entirely consistent for all components with simulated results by HEC-HMS. It means that the applied methods to the FAM were implemented properly.

• 한국수자원학회논문집
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• 제34권6호
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• pp.627-640
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• 2001

일반적으로 합성단위도법은 강우-유출기록이 없는 유역의 설계홍수량 산정을 위해 제안되었다. 그러나 국내에서는 아직까지 자료의 부족 등으로 외국에서 개발된 각종 유출모의 모형이 주로 이용되고 있다. 따라서 그 동안 축적된 국내의 강우-유출 자료를 이용하여 국내의 수문특성엥 적합한 유출모형의 개발이 절실한 상황이다. 이를 위해 본 연구에서는 설마천 유역의 2개 지점과 IHP 대표유역인 평강창, 보청천, 위천의 17개 지점에 대해 그 동안 축 (중략) 특성 관련 연구결과를 종합하여 새로운 합성단위도법을 개발하였다. 개발된 합성단위도는 유역특성인자와 단위도치식 치(첨두시간, 첨두유량)와의 다중회귀분석을 통해 유역면적-유로연장-유로경사의 3가지 변수로 구성되는 효 (중략) 전국을 있었다. 따라서 우리나라에서는 아직까지 수계별로 합성단위도를 분리하여 제시하기는 무리라고 보여지 (중략)

• 한국농공학회지
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• 제4권1호
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• pp.583-597
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• 1961