洪水频率分析成果是水利水电规划设计的依据之一。目前,国内外推求设计洪水应用比较广泛的方法,是数理统计和水文气象两类方法。水文工作者普遍感到,现有洪水实测系列太短,历史洪水可靠性较差,对推算的稀遇洪水把握性不大。而可能最大洪水不仅受资料条件的限制,且因其理论不够完善,人为的任意性较大,尤其在观测点极为稀少的地区,使用现有方法困难更大。所以,水文工作者在实际工作中,一方面尽可能采用几种方法,根据所用资料的数量、精 The result of flood frequency analysis is one of the bases of water conservancy and hydropower planning and design. At present, the method of deducing design floods at home and abroad is widely used, which is the two methods of mathematical statistics and hydro-meteorology. It is generally felt by hydrological workers that the existing flood measurement series is too short and the reliability of historical floods is poor, and the grasped floods rarely reach a conclusion. However, the maximum flooding may not only be limited by the conditions of the data, but also due to its imperfect theory and artificial arbitrariness, especially in areas where observation points are extremely scarce. The existing methods are more difficult. Therefore, the actual work of hydrologists, on the one hand, as far as possible using several methods, according to the amount of information used, refined