Modelling Unusual Behaviour of Rainfall Using Truncated GEV Distribution in a Mixture Framework

A truncated generalised extreme value (GEV) distribution in a mixture framework is proposed for the analysis of abnormal rare events in heterogeneous data representing environmental phenomena. The proposed extremal mixture model produced a better understanding of the extremal rainfall behaviour in the Mula-Mutha-Bhima subbasin in India. It gave some realistic extrapolation of quantiles corresponding to a very low probability of exceedance useful in water resources planning and design of civil infrastructure. The proposed model could be useful for the class of problems characterising extreme events and heterogeneity in fields like hydrology, environment and so on.