L 및 LH-모멘트법과 지역빈도분석에 의한 가뭄우량의 추정(I) - L-모멘트법을 중심으로 -

이순혁 ( Lee Soon Hyuk ),윤성수 ( Yoon Seong Soo ),맹승진 ( Maeng Sung Jin ),류경식 ( Ryoo Kyong Sik ),주호길 ( Joo Ho Kil ) 한국농공학회 2003 韓國農工學會誌 : 전원과 자원 Vol.45 No.5

This study is mainly conducted to derive the design drought rainfall by the consecutive duration using probability weighted moments with rainfall in the regional drought frequency analysis. It is anticipated to suggest optimal design drought rainfall of hydraulic structures for the water requirement and drought frequency of occurrence for the safety of water utilization through this study. Preferentially, this study was conducted to derive the optimal regionalization of the precipitation data that can be classified by the climatologically and geographically homogeneous regions all over the regions except Cheju and Ulreung islands in Korea. Five homogeneous regions in view of topographical and climatological aspects were accomplished by K-means clustering method. Using the L-moment ratio diagram and Kolmogorov-Smirnov test, generalized extreme value distribution was confirmed as the best fitting one among applied distributions. At-site and regional parameters of the generalized extreme value distribution were estimated by the method of L-moments. Design drought rainfalls using L-moments following the consecutive duration were derived by the at-site and regional 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 drought rainfall derived by at-site and regional analysis in the observed an simulated data were computed and compared. In has shown that the regional frequency analysis procedure can substantially more reduce the RRMSE. RBIAS and RR in RRMSE than those of at-site analysis in the prediction of design drought rainfall. Consequently, optimal design drought rainfalls following the regions and consecutive durations were derived by the regional frequency analysis.

L-모멘트법에 의한 가뭄우량의 지역빈도분석

이순혁 ( Lee Soon-hyuk ),윤성수 ( Yoon Seong-soo ),맹승진 ( Maeng Sung-jin ),류경식 ( Ryoo Kyong-sik ),주호길 ( Joo Ho-kil ) 한국농공학회 2003 한국농공학회 학술대회초록집 Vol.2003 No.-

This study was mainly conducted to derive the design drought rainfall by the consecutive duration using probability weighted moments with rainfall in the regional drought frequency analysis. Selecting the drought rainfall series by the consecutive durations of drought observed for the long period all over the regions in Korea, optimal regionalization of the drought rainfall was classified by the climatologically and geographically homogeneous regions. Using the L-moment ratio and Kolmogorov-Smimov test, resonable frequency distribution for the drought rainfall was selected by the regions and consecutive periods of drought. Design drought rainfalls by the regions and consecutive durations were derived and compared by at-site and regional drought frequency analysis using the method of L-moments.

LH-모멘트법과 지역빈도분석에 의한 가뭄우량의 추정

이순혁 ( Lee Soon Hyuk ),윤성수 ( Yoon Seong Soo ),맹승진 ( Maeng Sung Jin ),류경식 ( Ryoo Kyong Sik ),주호길 ( Joo Ho Kil ),박진선 ( Park Jin Seon ) 한국농공학회 2004 한국농공학회 학술대회초록집 Vol.2004 No.-

본 연구에서는 확률가중모멘트의 차수를 증가시킨 고차확률가중모멘트인 L1, L2, L3 및 L4-모멘트법(일명 LH-모멘트법)에 의한 지점 및 지역빈도분석과 Arc-View에 의한 빈도별 가뭄우량의 추정에 관한 연구로서 Lee et al(2003)에 적용한 것과 동일한 4가지 확률분포형을 사용하였다. 그리고 적용된 확률분포형들의 실측가뭄우량자료에 대한 LH-모멘트비를 산정하고 LH-모멘트비도와 K-S 검정에 의한 적정한 확률분포형을 선정하였다. 이어서 강우관측지점별 지속기간별 가뭄우량의 지점 및 지역빈도분석에 의한 빈도별 가뭄우량을 유도하고 Monte Carlo 기법에 의해 모의발생된 강우관측지점별 지속기간별 실측가뭄우량의 지점 및 지역빈도분석에 의한 빈도별 가뭄우량을 유도하였다. 또한, 실측가뭄우량과 모의발생된 가뭄우량의 지점 및 지역빈도분석에 의한 빈도별 가뭄우량의 비교분석을 실시하였다. 본 연구에서는 Lee et al(2003)에서 결과된 빈도별 적정 가뭄우량과 본 연구에서 결과된 빈도별 적정 가뭄우량과의 비교분석에 의해 최종적으로 지역별 지속기간별로 신빙성 높은 빈도별 가뭄우량을 제시하고 또한, 이를 Arc-View를 이용하여 전국을 망라한 지속기간별 빈도별 가뭄우량도를 작성하였다. LH-moment ratio diagram and the Kolmogorov-Smirnov test on the Gumbel (GUM), Generalized Extreme Value (GEV), Generalized Logistic (GLO) and Generalized Pareto (GPA) distributions were accomplished to get optimal probability distribution. Design drought rainfalls were estimated by both at-site and regional frequency analysis using LH-moments and GEV distribution, which was confirmed as an optimal one among applied distributions. Design rainfalls were estimated by at-site and regional frequency analysis using LH-moments, the observed and simulated data resulted from Monte Carlo techniques. Design drought rainfalls derived by regional frequency analysis using LI, L2, L3 and L4-moments (LH-moments) method have shown higher reliability than those of at-site frequency analysis in view of RRMSE (Relative Root-Mean-Square Error), RBIAS (Relative Bias) and RR (Relative Reduction) for the estimated design drought rainfalls. Relative efficiency were calculated for the judgment of relative merits and demerits for the design drought rainfalls derived by regional frequency analysis using L-moments and IA, L2, L3 and L4-moments. Design drought rainfalls derived by regional frequency analysis using L-moments were shown as more reliable than those using LH-moments. Design drought rainfalls for the classified five homogeneous regions following the various consecutive durations were derived by regional frequency analysis using L-moments, which was confirmed as a more reliable method through this study.

L 및 LH-모멘트법과 지역빈도분석에 의한 가뭄우량의 추정 (II)- LH-모멘트법을 중심으로 -

이순혁 ( Lee Soon-hyuk ),윤성수 ( Yoon Seong-soo ),맹승진 ( Maeng Sung-jin ),류경식 ( Ryoo Kyong-sik ),주호길 ( Joo Ho-kil ),박진선 ( Park Jin-seon ) 한국농공학회 2004 한국농공학회논문집 Vol.46 No.5

In the first part of this study, five homogeneous regions in view of topographical and geographically homogeneous aspects except Jeju and Ulreung islands in Korea were accomplished by K-means clustering method. A total of 57 rain gauges were used for the regional frequency analysis with minimum rainfall series for the consecutive durations. Generalized Extreme Value distribution was confirmed as an optimal one among applied distributions. Drought rainfalls following the return periods were estimated by at-site and regional frequency analysis using L-moments method. It was confirmed that the design drought rainfalls estimated by the regional frequency analysis were shown to be more appropriate than those by the at-site frequency analysis. In the second part of this study, LH-moment ratio diagram and the Kolmogorov-Smirnov test on the Gumbel (GUM), Generalized Extreme Value (GEV), Generalized Logistic (GLO) and Generalized Pareto (GPA) distributions were accomplished to get optimal probability distribution. Design drought rainfalls were estimated by both at-site and regional frequency analysis using LH-moments and GEV distribution, which was confirmed as an optimal one among applied distributions. Design rainfalls were estimated by at-site and regional frequency analysis using LH-moments, the observed and simulated data resulted from Monte Carlotechniques. Design drought rainfalls derived by regional frequency analysis using L1, L2, L3 and L4-moments (LH-moments) method have shown higher reliability than those of at-site frequency analysis in view of RRMSE (Relative Root-Mean-Square Error), RBIAS (Relative Bias) and RR (Relative Reduction) for the estimated design drought rainfalls. Relative efficiency were calculated for the judgment of relative merits and demerits for the design drought rainfalls derived by regional frequency analysis using L-moments and L1, L2, L3 and L4-moments applied in the first report and second report of this study, respectively. Consequently, design drought rainfalls derived by regional frequency analysis using L-moments were shown as more reliable than those using LH-moments. Finally, design drought rainfalls for the classified five homogeneous regions following the various consecutive durations were derived by regional frequency analysis using L-moments, which was confirmed as a more reliable method through this study. Maps for the design drought rainfalls for the classified five homogeneous regions following the various consecutive durations were accomplished by the method of inverse distance weight and Arc-View, which is one of GIS techniques.