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Optimal distance exponent of inverse distance method

역거리법의 최적 거리 지수

  • Yoo, Ju-Hwan (Department of Civil & Environmental Engineering, U1 University)
  • 유주환 (유원대학교 토목환경공학과)
  • Received : 2017.12.27
  • Accepted : 2018.02.21
  • Published : 2018.05.31

Abstract

We calculated the optimal exponent values based on the hourly rainfall data observed in South Korea by treating the exponent value as a variable without fixing it as a square in the inverse distance method. For this purpose, rainfall observation stations providing the data are classified into four groups which are located at the Han river upstream, downstream, the Geum river upstream, and the Nakdong river midstream area. A total of 52 cases were analyzed for seven stations in each group. The optimal exponent value of distance was calculated in a case including one base station and four surrounding stations in a group. We applied the golden section search method to calculating this optimum values using rainfall data for 10 years (2004~2013) and verified the optimum values for the last three years (2014~2016). We compared and analyzed two results of the conventional inverse distance method and the inverse distance method in this study. The optimal values of distance exponent obtained in this study were 3.280, 1.839, 2.181, and 2.005 respectively, in the four groups, and totally mean value was 2.326. It is shown the proposed inverse distance method applying the optimal exponent is superior to the conventional inverse distance method.

역거리법에 포함된 지수 값을 제곱으로 고정하지 않고 변수로 취급하여 강수량 자료를 바탕으로 지수 값의 최적치를 산출하였다. 이를 위해서 한강 상류부, 한강 하류부, 금강 상류부, 낙동강 중류부 등 4개 Group으로 나누고 각 Group 내 7개 관측소에 대하여 총 52개의 Case를 분석하였다. 각 Group에서 기준 관측소 1개와 주변관측소 4개를 조합한 Case별로 거리 지수 값의 최적치를 구하였다. 이 최적치를 산출하기 위해서 황금비 분할조사법을 적용하였고 강수 자료는 10년(2004~2013년) 간의 시우량 자료를 사용하였다. 이와 같이 구한 최적치를 최근 3년(2014~2016년) 간에 대하여 검증하였다. 본 연구에서 구한 최적의 거리 지수 값은 4개 Group에서 평균적으로 각각 3.280, 1.839, 2.181, 2.005로 나타났고 전체 평균하면 2.326이었다. 그리고 최적의 지수 값을 적용한 역거리법은 지수 값을 제곱으로 한 기존 역거리법과 비교하여 우수함을 보였다.

Keywords

References

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