1984年10月《河南省中小流域设计暴雨洪水图集》出版发行，图集中的推

1984年10月《河南省中小流域设计暴雨洪水图集》出版发行，图集中的推理公式法广泛应用于山丘区水文资料缺乏的中小流域设计洪水计算。近年来与实测洪水成果对比论证，其计算结果偏大，特别是中小洪水更加明显，已超出规范规定的许可范围。经综合分析，发现是采用平均入渗率造成的问题。依据《水利水电工程设计洪水计算规范》及产流理论，阐明问题原因，明确参数概念，采用洪峰汇流时间的净雨对方法进行改进，使洪水成果接近实际，从而完善了河南省推理公式法。

In October 1984, the atlas of design rainstorm and flood in small and medium-sized basins in Henan Province was published. The reasoning formula method in the atlas is widely used in the calculation of design flood in small and medium-sized basins lacking hydrological data in hilly areas. Compared with the measured flood results in recent years, the calculated results are too large, especially the medium and small floods, which has exceeded the allowable scope specified in the specification. Through comprehensive analysis, it is found that the problem is caused by the average infiltration rate. According to the code for design flood calculation of water resources and hydropower projects and the runoff generation theory, this paper expounds the causes of the problems, defines the concept of parameters, and improves the method by using the net rain of flood peak confluence time, so as to make the flood results close to reality, so as to improve the reasoning formula method of Henan Province.

In October, 1984, the Atlas of Design Rainstorm and Flood in Small and Medium-sized Watershed of Henan Province was published, and the inference formula method in the atlas was widely used to calculate the design flood in small and medium-sized watersheds lacking hydrological data in hilly areas. In recent years, compared with the measured flood results, the calculated results are too large, especially the small and medium-sized floods, which have exceeded the allowable range stipulated in the code. Through comprehensive analysis, it is found that the problem is caused by using average infiltration rate. According to the Code for Design Flood Calculation of Water Conservancy and Hydropower Engineering and the runoff generation theory, the causes of the problems are clarified, the concept of parameters is clarified, and the method is improved by using the net rain at the peak concentration time, so that the flood results are close to the reality, thus perfecting the inference formula method in Henan Province.