洪水频率分析常苦于资料太短,即使考虑历史调查洪水并作特大值处理,频率曲线的稀遇洪水部分定线仍然困难和不可靠.本文提出利用支流末端洪水平流沉积推算干流几千年前洪水以及由这些古洪水、历史(调查)洪水、实测洪水构成的不连序系列进行频率分析的方法.该法可使频率曲线最重要的稀遇洪水部分精度显著提高. Flood frequency analysis often suffer from the data is too short, even taking into account historical surveys of floods and dealing with large value, the frequency curve of the rare part of the alignment of the flood is still difficult and unreliable.This paper proposes the use of tributary flood advection deposition mainstream thousands of years ago As well as the frequency analysis of these discontinuous series of paleo-floods, historical (survey) floods, and measured floods, which can significantly improve the precision of the most important parts of the flood spectrum of the frequency curve.