PARAMETRIC UNCERTAINTY IN STOCHASTIC PRECIPITATION MODELS - WET DAY AMOUNTS

A methodology was developed to quantify the uncertainty associated wit h maximum likelihood parameter estimates used in the wet day amount co mponent of stochastic rainfall models. Traditional point parameter est imates were combined with interval estimates to construct a probabilis tic region of parametric uncertainty. Regions of model uncertainty wer e then constructed from the region of parametric uncertainty. The wet day amount model was implemented by repeatedly selecting parameters fr om a bivariate normal distribution. The results of this test suggested that the amount model was sensitive to small changes in parameters. T he model was least sensitive to parametric uncertainty for small wet d ay amounts and increased in sensitivity toward large amounts.