A Synthesis of Unit Hydrograph by a Correlation Analysis between the Basin Characteristics and the Runoff-Characteristics - Han and Geum River Basin -

유역특성과 유출특성간의 상관관계 해석에 의한 단위유량도의 합성 - 한강 및 금강유역 -

An attempt is made to develope a scheme for synthesizing unit hydrograph for any arbitrary small watershed in the Han or Geum River basin, which can be applied in determining various sizes of design flood for flood control prijects. Stage gauging stations, seven in the Han and five in the Geun River basin with rating curves, were selected as subbasins for the analysis. Unit hydrographs of 2-hour duration were derived for several heavy storm events using the storm and the corresponding flood runoff data for each subbasin. The Clark method programmed by the Hydrologic Engineering Center, U.S. Corps of Engineers, was utilized for derivation of instantaneous unit hydrographs which were, in turn, converted into 2-hour unit hydrograph. By averaging the 2-hour unit hydrographs from several storm events a representative 2-hour unit hydrograph was determined for each subbasin and hence a separate derivation of dimensionless unit hedrograph was also possible for the Han and Geum River basins. The physiographic characteristics such as stream length, distance to the centroid of each watershed were correlated with the characteristic parameters of the derived unit hydrograph for the subbasins within two large basins. correlation analyses between the characteristic parameters were also made. These correlation analyses resulted a series of four equations and a dimensionless unit hydrograph for the two large basins, which made it possible to draw a synthetic 2-hour unitgraph for any small watershed within the Han or Geum River basin. A detailed procedure for aplying the derived method for an arbitrary basin is summarized with one sample computation for each of the two basins. A comparison of the actually derived 2-hour unit hydrogrograph and the synthesized one showed a fair agreement. A recommendation is made for the further study.

본연구는 1974년 건설부 수자원국의 연구사업중의 하나인 $\ulcorner$홍수량 추정을 위한 합성단위유량도유도의 연구$\Ircorner$의 일부로서 건설부에서 제공한 재정적 후원에 감사를 드린다.