The Probability Density Evolution Method for Flood Frequency Analysis: A Case Study of the Nen River in China

Abstract

Abstract:A new approach for flood frequency analysis based on the probability density evolution method (PDEM) is proposed. It can avoid the problem of linear limitation for flood frequency analysis in a parametric method and avoid the complex process for choosing the kernel function and window width in the nonparametric method. Based on the annual maximum peak discharge (AMPD) in 54 years from the Dalai hydrologic station which is located on the downstream of Nen River in Heilongjiang Province of China, a joint probability density function (PDF) model about AMPD is built by the PDEM. Then, the numerical simulation results of the joint PDF model are given by adopting the one-sided difference scheme which has the property of direction self-adaptive. After that, according to the relationship between the marginal function and joint PDF, the PDF of AMPD can be obtained. Finally, the PDF is integrated and the frequency curve could be achieved. The results indicate that the flood frequency curve obtained by the PDEM has a better agreement with the empirical frequency than that of the parametric method widely used at present. The method based on PDEM is an effective way for hydrologic frequency analysis. OPEN ACCESSWater 2015, 7 5135 Keywords: probability density evolution method (PDEM); annual maximum peak discharge (AMPD); flood frequency analysis

Identification of the Most Suitable Probability Distribution Models for Maximum, Minimum, and Mean Streamflow

“…Another approach is the probability density evolution method (PEDM) developed from probability-weighted moments [31]. Its advantages are that it circumvents the linear limitations in flood frequency analysis that are often encountered in parametric methods and avoids the problem of selecting the kernel function and window width in some nonparametric approaches [35]. However, its use in flood frequency analysis is still limited.…”