THEORY OF EXTREME EVENTS AND PROBABILITY DISTRIBUTIONS OF FLOODING CHARACTERISTICS

摘要

The character of distribution of the maximal runoff of rain floods on the rivers of Russia was investigated. Two approaches are discussed: using of mix of the distributions, including the component with so-called heavy tail (Pareto distribution), and approximation of tails of distributions on the base of generalized Pareto distribution (for a range of maximal values). The problem of accuracy increase for the estimation of distribution parameters by means of data grouping was investigated. Mean regional values of parameters combined with the method of L-moments for an estimation of unknown parameters are recommended for practical use of results of researches.