基于伽马函数的洪水频率适线方法研究  

Research on flood frequency fitness line method based on Gamma Function

作　　者：刘媛媛[1,2,3] 刘正风 刘业森 李匡[1,2] 刘舒 LIU Yuanyuan;LIU Zhengfeng;LIU Yesen;LI Kuang;LIU Shu(China Institute of Water Resources and Hydropower Research,Beijing 100038;Research Center on Flood and Drought Disaster Reduction of the Ministry of Water Resources(Flood and Drought Disaster Prevention Center),Beijing 100038;Key Laboratory of Water Safety for Beijing-Tianjin-Hebei Region of Ministry of Water Resources,Beijing 100038;General Institute of Water Resources and Hydropower Planning and Design,Beijing 100120)

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038 [2]水利部防洪抗旱减灾工程技术研究中心(水旱灾害防御中心),北京100038 [3]水利部京津冀水安全保障重点实验室,北京100038 [4]水利部水利水电规划设计总院,北京100120

出　　处：《中国防汛抗旱》2025年第3期35-38,85,共5页China Flood & Drought Management

基　　金：中国水利水电科学研究院揭榜挂帅类项目(减JZ0145B042024);水利青年拔尖人才项目(JHQB202221)。

摘　　要：在工程规划设计中,普遍采用P-Ⅲ曲线来计算设计洪水。然而,近年来全球气候变化导致实测洪峰流量频繁突破历史纪录,因此从工程安全角度出发,需要调整频率曲线,使其更倾向于大值区。传统上,这种调整是通过改变CV与CS的比值来实现的,但这种方法会导致曲线扭曲和变形,从而偏离理想形状。基于此,提出一种新的方法:基于伽马函数,对大值区进行适当加密,并利用伽马函数的反函数自动进行曲线拟合。这种方法不仅能够保持P-Ⅲ曲线的合理形状,确保曲线与频率点的吻合度较好,还能实现P-Ⅲ曲线向历史大值区的偏移,从而更准确地反映洪水风险。此外,这种方法还显著提高了工作效率和计算精度,为工程设计提供了更为科学和精确的洪水计算依据。In engineering planning and design,the P-Ⅲcurve is usually used to calculate the design flood.However,in recent years,global climate change has led to frequent record breaking of flood peak flows,so from the perspective of engineering safety,it is necessary to adjust the frequency curve so that it is more inclined to the high-value region.In the usual method,this adjustment is realized by changing the ratio of C_(v)/C_(s).However,this method leads to distortion and deformation of the curve,thus deviating from the ideal shape.Based on this,a new method is proposed:based on the gamma function,the high-valued region is appropriately encrypted and the inverse function of the gamma function is utilized for automatic curve fitting.This method not only maintains the reasonable shape of the P-Ⅲcurve and ensures a better fit of the curve to the frequency points,but also realizes the offset of the P-Ⅲcurve to the historical high-value area,thus reflecting the flood risk more accurately.In addition,this method significantly improves the working efficiency and calculation accuracy,providing a more scientific and accurate basis for flood calculation for engineering design.

关 键 词：设计洪水 洪水频率 伽马函数 频率曲线 

分 类 号：P338[天文地球—水文科学]