Rainfall Quantile Estimation using Regional Frequency Analysis and Cluster Analysis in Han River Basin Younghun Jung1, Woo Sung Nam2, Kyung Won Joo3, and Jun-Haeng Heo4
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Ph.D candidate, School of Civil and Environmental Engineering, Yonsei University, YERC 307B, Hydro Lab., 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-749, Korea (Tel: +82-2-1597, Fax: +82-6280-1597, e-mail:
[email protected]) 2 Ph.D candidate, School of Civil and Environmental Engineering, Yonsei University, YERC 307B, Hydro Lab., 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-749, Korea (Tel: +82-2-1597, Fax: +82-6280-1597, e-mail:
[email protected]) 3 Ph.D candidate, School of Civil and Environmental Engineering, Yonsei University, YERC 307B, Hydro Lab., 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-749, Korea (Tel: +82-2-1597, Fax: +82-6280-1597, e-mail
[email protected]) 4
Professor, School of Civil and Environmental Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-749, Korea (Tel: +82-2-1597, Fax: +82-364-5300, e-mail:
[email protected])
A374,
The aim of this study is to investigate and determine regions and to derive regional rainfall quntile estimates for 104 gauged sites in Han River basin in South Korea using an index flood method with L-moments parameter estimation and Regional Shape Estimation (RSE) method. It is very important to determine homogeneous regions using cluster analyses. In recent years, the problem of clustering in various data has been gaining significant attention. Cluster analysis using various at-site characteristics is used to determine homogeneous rainfall regions. For the regionalization of Han River basin, 4 cluster analyses such as average linked method, WARD method, two-step method, and k-means method are applied for grouping regions by using variables of meteorology and geomorphology. The results from cluster analysis are compared for each region using various distributions. Accurate measures for the estimated regional growth curves and quantiles have been calculated for the candidate distributions using Monte Carlo simulations. Monte Carlo simulation is used to evaluate the quantile estimates on the basis of the relative root mean square error. And then, regional rainfall quantiles by index flood and regional shape estimation methods are compared based on the applied cluster methods for rainfall data of Han River basin in South Korea.
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REFERENCES 1 Heo, J.H., Boes, D.C., and Salas, J.D. (1990) Regional Flood Frequency Modeling and Estimation, Water Resour. Pub., No. 101, Colorado State Univ., Fort Collins, Colorado, USA. 2 Heo, J.H., Lee, Y.S., Shin, H., Kim, K.D. (2007). “Application of regional rainfall frequency analysis in South Korea(Ⅰ): rainfall quantile estimation.” Korea Water Resources Association, 27(2B), pp. 101-111. 3 Hosking, J.R.M. and Wallis, J.R. (1997). Regional Frequency Analysis. Cambridge University Press. 4 Lee, Y.S., Heo, J.H., Nam, W.S., Kim, K.D. (2007). “Application of regional rainfall frequency analysis in South Korea(Ⅱ): Monte Carlo simulation and determination of appropriate method.” Korea Water Resources Association, 27(2B), pp. 113-123. 5 Rao, A.R. and Srinivas, V.V. (2006). “Regionalization of watersheds by fuzzy cluster analysis.” Journal of Hydrology 318, pp. 57-79.
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