Analysis of the rare and extreme values through statistical modeling is an important issue in economic crises,climate forecasting,and risk management of financial portfolios.Extreme value theory provides the probability models needed for statistical modeling of extreme values.There are generally two ways to identifying the extreme values in a data set,the block-maxima and the peak-over-threshold method.The block-maxima method uses the Generalized Extreme Value distribution and the peak-over-threshold method uses the Generalized Pareto distribution.