Contrast of Generalized Logistic Distribution in 31 Historical Records of Annual Extreme Events

The Generalized Logistic distribution is the most recent whose application has been established as precept. Thus, comparing it with the other two that preceded it: the Log–Pearson type III in USA and the General Extreme Values in England, is of high importance. In this work, the relevance of probabilistic analysis and the above mentioned distributions in design flood estimation is pointed out. For the most recent, a fitting method of L–moments is described in detail for the estimation of its three parameters, also a fitting by minimizing the quadratic mean error through numerical optimization is proposed. The results of the application of this distribution to 31 records, using both cited methods, are compared with the optimal ones obtained using the General Extreme Values and Log–Pearson type III models. It is concluded that the Generalized Logistic distribution is a good choice for records with high L–kurtosis quotients and its predictions in general are more extreme in high return periods when applied to records with outliers.