水文中往往需要研究水文变量在空间上的分配规律, 同频率地区组成法是目前解决该问题的一个重要方法, 但其中仍有一些理论问题悬而未解。以“上下同频、区间相应”的组成方案为例, 区间相应量的频率 C 与“同频”中 设计频率 P 之间的大小关系, 无法判断, 目前尚无理论证明。因此, 对正态分布和 P-ó 分布, 分别通过理论推导和统计试验途径, 明确了 C 与 P 之间关系。对设计洪水问题, 根据“上下同频、区间相应”求得的区间相应洪量, 其频率 C 将大于设计频率P ; 对径流或枯水设计问题而言, 区间径流量的频率 C 将小于设计保证率P 。研究结果从理论 上进一步明晰了同频率地区组成法中相应量的频率问题。

The spatial distribution rules of hydrological variables are often studied in hydrology. The Equivalent Frequency Regional Composition (EFRC) method is an important approach to solving this problem at present. However, there are still some theoretical issues that remain unsolved. Take as an example the composition scheme of "same design frequencies at upstream and downstream, with corresponding value at the interval", we cannot determine which is larger between the frequency of the interval area (C) and the design flood frequency (P) at both upstream and downstream due to a lack of theoretical proof. In this study, we investig ated the relationships between C and P for the normal and Pearson type III ( PE3) distributio ns by means of theo retical deriv at ion and Mo nte Carlo ( MC) ex periment . Results showed that C is lar ger than P for the design flood problem, while for the design problem of runoff or lowflow , P is larger than C. Ther efore, this study has clarified in theory the design frequency of corresponding value at the interval for the EFRC method.

国家重点研发计划重点专项( 2016YFC0402709) ; 国家自然科学基金( 51709073)