Distribution‐free methods for estimating flood and streamflow exceedance probabilities by correlation

Abstract
This paper deals with the problem in which it is necessary to infer the probabilistic characteristics of a streamflow variableyt(e.g., annual peak discharge, or accumulated streamflow during some time interval) given a correlated longer recordxt(e.g., annual peak discharge at a gaging site with longer record; rainfall during the same time interval). In particular, it is necessary to estimate probabilities of the formP(yy0) for givenY0. Conventional methods make assumptions about the joint probability distribution ofxtandyt; the methods developed in this paper require no such assumption, being distribution free. Estimates ofP(yY0) are also obtained by Bayesian methods.