In order to ascertain the maximum value of a variable for which design needs to be carried out, a set of high values of the variable is used to perform extreme value analysis (EVA). The simplest method is graphical approach and this is often adopted by designers. However, order statistics approach like Lieblein technique improves accuracy of the estimated distribution parameters and consequently the extreme values. For important structures, for which very low risk is desired, such methods are more appropriate. In this article, the Lieblein method has been applied for the rainfall records from a western coastal site in India and compared with the results of graphical method. The site receives most of the rainfall during south-west monsoon during the four months of June, July, August and September. Though the errors were found to be on the conservative side, the estimates of extreme rainfall from the graphical method would yield expensive designs. Frechet distribution was more suitable as compared to Gumbel distribution for modeling the rainfall extremes at the site. The extreme daily rainfall values for the site are 629 mm, 806 mm, 1844 mm, and 4223 mm for return periods of 50 years, 100 years, 1000 years, and 10000 years respectively.
South-west Monsoon, Rainstorms, Extreme Value Analysis, Graphical Technique, Lieblein Technique, Least Square Method
