NOTE ON THE ANALYTICAL EXPRESSION OF THE INTEREVENT TIME CHARACTERISTICS FOR BARTLETT-LEWIS TYPE RAINFALL MODELS

The random parameter Bartlett-Lewis rectangular pulses model has been shown to be an effective tool in reproducing the features of the rainf all process at various time-scales, including features of the time-ser ies of events. The current paper yields exact expressions of these fea tures, i.e. the distribution of the inter-event time, the number of ev ents per month and the average duration of rainfall events. Equations are given for both this model and the simpler Bartlett-Lewis rectangul ar pulses model. These equations are applied to the case of rainfall d ata from Birmingham (UK) to provide optimal parameters for the random parameter model.