国内外设计洪水计算方法的比较研究

Comparative Study of Different Design Flood Estimation Methods

摘要: 设计洪水是水利水电工程设计和流域规划中的关键问题。本文介绍了国内外基于流量资料推求设计洪水的计算方法及几种常用的洪水频率分析模型。构建了P-III/CF、P-III/LM、Gumbel/LM和Log P-III/MM等四种洪水频率分析模型，比较了不同模型估计的设计洪水值。研究表明，中国规范推荐的P-III/CF模型比其他模型的估计结果偏大10%~15%；在开展设计洪水计算时，样本资料系列的代表性非常重要，同时也要认识到历史洪水资料具有可能提高或损害系列的代表性；不同洪水频率分析模型的成果差异，跟模型构建中的频率分布线型、参数估计方法和适线准则均有关；基于设计洪水计算中存在的各种客观现实条件，在开展设计洪水研究和计算时，应充分重视基础资料的“三性”审查及分析过程和成果的合理性分析。

Abstract: The design flood is the key problem in hydropower project designing and watershed planning. The design flood estimation methods, the most frequently-used distribution functions and parameter estimation methods were introduced. Four kinds of flood frequency analysis models were built for the comparative study. The results demonstrate that the design floods estimated by the P-III/CF model which is recommended by Chinese regulation are larger by 10% - 15% than other models. It is also shown that the representativeness of data series is significantly important. The historical flood information either can enhance or damage sample representativeness. The differences of results estimated by different models greatly have correlation with frequency distribution function, parameter estimation methods and curving-fitting guidelines. Taking the practical difficulties in flood designing into consideration, full at-tention should be paid to the reasonable analysis of basic data, the calculation process and the results.