地区线性矩法在四川省暴雨频率分析中的应用

Regional Frequency Analysis in Hydrological Frequency Analysis of Sichuan Province

[目的]利用地区线性矩法改进我国传统洪水频率分析的研究。[方法]基于地区线性矩法的基本思想和原理,对四川省进行水文气象一致区的划分,并且利用蒙特卡洛模拟检测获得各个一致区的最优频率分布线型,根据各个一致区的最优频率分布线型估算得到各个站点不同重现期下的暴雨频率设计值。[结果]四川省可划分为4个水文气象一致区,各个水文气象一致区的最优频率分布线型分别为1区为Wakeby分布,2区为广义极值分布(GEV),3和4区均为广义逻辑斯蒂分布(GLO)。研究表明四川省各个地区的降雨分布及其不均,水文气象一致区4区为主要的暴雨区,其次为一致区2区,这与四川省的降雨特点是一致的。[结论]地区线性矩法相比于我国传统的暴雨频率分析方法可以获得更为合理准确的设计值,可以为我国的防洪工程提供一定的参考和借鉴。

[Objective]The purpose of this study is to improve the results of traditional flood frequency analysis in China by using the regional frequency analysis.[Method]Based on the basic idea and principle of regional frequency analysis,Sichuan province was divided into homogeneous regions,and Monte Carlo simulation was used to obtain the optimal frequency distribution of each homogeneous region.The precipitation amounts under different return period were estimated according to the optimal frequency distribution of each homogeneous region.[Result]Sichuan province could be divided into four homogeneous region.The optimal frequency distributions of each homogeneous regions respectively were:Region 1 st was Wakeby distribution,region 2 was Generalized Extreme Value Distribution(GEV),and region 3 and region4 were Generalized Logistic Distribution(GLO).Besides,the rainfall in the eastern part of Sichuan province was more,the region 4 was the main rainstorm area,followed by the region 2,which was consistent with the characteristics of rainfall in Sichuan province.[Conclusion]The results accumulated some experience in the application of regional frequency analysis in China,which promoted the study of hydrological frequency analysis in China and proved the applicability of regional frequency analysis in China.