指数Gamma分布在无资料地区水文频率分析中的应用研究

Application of Exponential Gamma Distribution in Hydrological Frequency Analysis for Un-Gauged Basins

指数Gamma分布在水文频率分析中具有良好的普适性和拟合弹性,该文探讨了该分布的参数等值图法在无资料地区的应用情况。选取江谷河流域作为研究区域,基于指数Gamma分布采用参数等值线图法对该地区暴雨序列进行频率分析,与采用参数等值线图法的P-Ⅲ型分布计算结果和采用优化适线法的指数Gamma分布计算结果进行对比研究,分析指数Gamma分布在无资料地区水文频率分析结果的可靠性。计算结果表明,采用参数等值线图法计算得到的设计值与优化适线法计算得到的设计值各有优劣,且多数优于采用参数等值线图法P-Ⅲ型分布的计算结果,指数Gamma分布可以用于无资料地区的水文频率计算。文中参数估计方法以期为我国水文频率分析及相关软件开发提供支撑。

The Exponential Gamma Distribution has good universality and fitting elasticity in hydrological frequency analysis.This paper discusses the application of this distribution in un-gauged basins.Selecting Jianggu river basin as the study area,the frequency of rainstorm is analyzed by using the parameter contour map method based on the Exponential Gamma Distribution.Compared with the results of P-III distribution using the parameter contour map method and the results of the Exponential Gamma Distribution using the optimal fitting method,the reliability of hydrological frequency analysis of the Exponential Gamma Distribution in un-gauged basins is analyzed.The calculation results show that the design values calculated by the Parametric Contour Map method and the Optimal Fitting method have their own advantages and disadvantages,and most of them are better than the calculation result of P-Ⅲdistribution by the Parametric Contour Map method.The Exponential Gamma Distribution can be used to calculate the hydrological frequency in un-gauged basins.The parameter estimation method in this paper is expected to provide support for the hydrological frequency analysis and related software development in China.