Comparison between the peaks over threshold method and the annual maximum method for flood frequency analyses
Hydrological Sciences Journal, (2014)Abstract
Flood frequency analyses (FFA) can be made by using two types of flood peak series, i.e. annual maximum (AM) and peaks over threshold (POT) series. This study represents a comparison of the results of both methods for the data from gauging station Litija 1 on the Sava River in Slovenia. Six commonly used distribution functions and three different parameter estimation techniques were considered in the AM analyses. The results showed a better performance of the method of L-moments when compared with the conventional moments and maximum likelihood method. The combination of the method of L-moments and the log-Pearson 3 distribution gave the best results among all the considered AM cases. The POT method gave better results than the AM method. Binomial distribution did not offer any noticeable improvement of the Poisson distribution for modelling the annual number of exceedances above the threshold.