Assessment of Parameters of the Generalized Extreme Value Distribution in Rainfall of the Peruvian North

The maximum rainfall in the Peruvian north behaves seasonally, concentrating between the first months of the year, however, few studies have analyzed its distribution over time through an analysis of extremes. The objective of the research was to evaluate the parameters of location, scale and shape of the generalized extreme value distribution in maximum rainfall in the Peruvian north corresponding to the Pacific 5 and Pacific 6 hydrological regions. The maximum daily rainfall data available was collected in the climatic stations of both regions, considering a minimum number of 15 years of records per station and a filter based on statistical and visual analysis, for which 138 stations were established. Subsequently, the adjustments were applied to ordinary moments and to linear moments of the generalized extreme value distribution and two types of hypothesis tests were used for each region that helped to validate the similarities of each parameter in both regions. The results show significant differences only in the location parameter, while, when contrasting the altitude, average rainfall and maximum rainfall of each hydrological region it was determined that there are high correlations with the location and scale parameters. Finally, it is concluded that both hydrological regions, the scale and shape parameters show a good performance for both adjustments based on the applied hypotheses and the location parameter showed that the Pacific 6 hydrological region is rainier than the Pacific 5 hydrological region.