In this study, the regional frequency analysis is used to determine each subbasin drought frequency with reliable monthly precipitation and the L-Moments method which is almost unbiased and has very nearly a normal distribution is used for the parameter estimation of monthly precipitation time series in Nakdong river basin. As the result of this study, the duration of '93-'94 is most severe drought year than any other water year and the drought frequency is established as compared the regional frequency analysis result of cumulative precipitation of 12th duration months in each subbasin with that of 12th duration months in the major drought duration. The Linear regression equation is induced according to linear regression analysis of drought frequency between Nakdong total basin and each subbasin of the same drought duration. Therefore, as the foundation of this study, it can be applied proposed method and procedure of this study to the water budget analysis considering safety standards for the design of impounding facilities large-scale river basin and for this purpose, above all, it is considered that expansion of reliable preciptation data is needed in watershed rainfall station.

전국적인 가뭄특성을 조사하고 '94-'95 가뭄의 심도를 기왕의 주요 가뭄과 비교평가하기 위하여 전국의 47개 소유역으로 분할한 후 강우량계열로부터 작성된 가뭄우량계열의 지역빈도분석을 실시하였다. L-모멘트법을 사용하여 적정확률분포의 매개 변수를 결정하였으며, 강우지속기간별, 재현기간별 가뭄우량을 산정하여 지속기간별 확률가뭄우량도를 작성하였다. 강우지속기간-재현기간-가뭄우량 관계를 고려하여 '94-'95 가뭄의 심도와 지역적 범위를 기왕의 주요가뭄과 비