2004 Volume 48 Pages 97-102
A flood frequency analysis using historical flood information was carried out for Lake Biwa since 18th century. The probability distributions of the standardized annual maximum water level andthe annual maximum rainfall totals for 30days was investigated and the effects of using historical flood information on flood frequency analysis were examined by plotting position. As results, it became apparent that these two extreme hydrological values obey the Gumbel distribution for Lake Biwa, and it was shown that the estimation precision of the quantile corresponding to the return period of several decades to a hundred years is largely improved by utilizing historical flood information.
