• Magazine of the Korean Society of Agricultural Engineers
• /
• v.36 no.4
• /
• pp.64-72
• /
• 1994

설계홍수량의 유도를 위해 일차적으로 극치계열인 금강, 영산강 및 석진강 수개 3개 유역의 연최고치계열을 중심으로 하여 SMEMAX법, 역변환(Power Transformation) 및 2단계역변환(Two step Power Transformation, TSPT)법에 의해 척도분포의 정규화를 위한 변환법의 효율성 검정과 설계홍수량의 유도 및 비교분석을 수행한 결과 SMEMAX 법과 Power 변환법에서는 정규분포화를 왜곡도계수의 영으로의 접근 시도는 가능하나 소설도, 3으로의 조건을 충족시킬 수 없었던 반면 2단계역변환법에서는 소설도, 3에 매우 근접된 결과를 가져오므로서 척도분포의 정규화를 기할 수 있었고 각각의 변환법에 유도된 설계홍수량간의 비교분석에서는 SMEMAX 및 Power 변환법에 비해 2단계역변환방법에 의한 설계 홍수량이 재현기간 10년 이상 실측치에 보다 접근된 좋은 결과를 나타내었다.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.34 no.4
• /
• pp.39-47
• /
• 1992

Derivation of reasonable design low flows was attempted by comparative analysis of design low flows was derived by Power and SMEMAX transformations for the normalizations of skewed distribution and by Type m extremal distribution presented in the first report of this study with annual low flows in the five watersheds of main river basins in Korea. The results were anslyzed and summarized as follows. 1.Basic statistics of annual low flows for the selected watersheds were calculated by using Power and SMEMAX transformations. 2.Power thansformation has found to be the best for the normalization of skewed distribution among others including log, square root and SMEMAX transformations. 3.Design low flows for the selected watersheds were derived by the Power and SMEMAX transformations. 4.Judging by the relative suitabilities of the Type III extremal distribution, Power and SMEMAX transformation, it was found that design low flows of all methods are closer to the observed data within 10 years of the return period and those of Power transformation can be acknowledzed as a reasonable one among others from the viewpoint of the median between values of Type m extremal distribution and SMEMAX transformation in addition to closing the observed than others over 10 years of the return period.