Estimation of Design Rainfall by the Regional Frequency Analysis using Higher Probability Weighted Moments and GIS Techniques (III) - On the Method of LH-moments and GIS Techniques -

고차확률가중모멘트법에 의한 지역화빈도분석과 GIS기법에 의한 설계강우량 추정 (III) - LH-모멘트법과 GIS 기법을 중심으로 -

  • Published : 2002.09.01

Abstract

This study was conducted to derive the regional design rainfall by the regional frequency analysis based on the regionalization of the precipitation suggested by the first report of this project. According to the regions and consecutive durations, optimal design rainfalls were derived by the regional frequency analysis for L-moment in the second report of this project. Using the LH-moment ratios and Kolmogorov-Smirnov test, the optimal regional probability distribution was identified to be the Generalized extreme value (GEV) distribution among applied distributions. regional and at-site parameters of the GEV distribution were estimated by the linear combination of the higher probability weighted moments, LH-moment. Design rainfall using LH-moments following the consecutive duration were derived by the regional and at-site analysis using the observed and simulated data resulted from Monte Carlo techniques. Relative root-mean-square error (RRMSE), relative bias (RBIAS) and relative reduction (RR) in RRMSE for the design rainfall were computed and compared in the regional and at-site frequency analysis. Consequently, it was shown that the regional analysis can substantially more reduce the RRMSE, RBIAS and RR in RRMSE than at-site analysis in the prediction of design rainfall. Relative efficiency (RE) for an optimal order of L-moments was also computed by the methods of L, L1, L2, L3 and L4-moments for GEV distribution. It was found that the method of L-moments is more effective than the others for getting optimal design rainfall according to the regions and consecutive durations in the regional frequency analysis. Diagrams for the design rainfall derived by the regional frequency analysis using L-moments were drawn according to the regions and consecutive durations by GIS techniques.

Keywords

References

  1. Lee, S. H., J. H. Park, K. S. Ryoo, H. K. Jee, T. K. Jeon and Y. H. Shin. 2001. Estimation of Design Rainfall by the Regional Frequency Analysis using Higher Probability Weighted Moments and GIS Techniques(I). Journal of the Korean Society of Agricultural Engineers 43(4): 57-68. (in Korean)
  2. Lee, S. H., J. H. Park, K. S. Ryoo, H. K. Jee, T. K. Jeon and Y. H. Shin. 2001. Estimation of Design Rainfall by the Regional Frequency Analysis using Higher Probability Weighted Moments and GIS Techniques(II). Journal of the Korean Society of Agricultural Engineers 43(5): 70-82. (in Korean)
  3. Maeng, S. J. 2002. Estimation of Design Flood by the Determination of Best Fitting Order for LH-Moments. Ph. D. Thesis. Cheongju, Chungbuk Prov.: Chungbuk National University, (in Korean)
  4. Wang, Q. J. 1997. LH Moments for Statistical Analysis of Extreme Events. Water Resources Research 33(2): 2841- 2848
  5. Wang, Q. J. 1997. Using Higher Probability Weighted Moments for Flood Frequency Analysis. Journal of Hydrology 194: 95-106 https://doi.org/10.1016/S0022-1694(96)03223-4