THE ROLE OF REGIONAL INFORMATION IN ESTIMATION OF EXTREME POINT RAINFALLS

Previous analysis has shown that inclusion of regional information imp roves at-site estimation of point rainfalls and makes it possible to o btain estimates at non-monitored sites. The basis for this analysis wa s a partial duration series (PDS) modelling of individual rainfall obs ervations and use of regional prior distributions for the PDS-paramete rs in a Bayesian estimation procedure. The advantages of this theoreti cally satisfactory, but also somewhat complicated procedure are evalua ted by means of a comparison with simplified procedures. These include modelling based on regional pooling of all point rainfall data into o ne sample from a common parent distribution and modelling with disrega rd of either the dependence between stations or the regional heterogen eity. The different models are analysed and compared with respect to t he uncertainty of the predicted extreme events.