A Proposed Rule-Discovery Scheme for Regionalisation of Rainfall-Runoff Characteristics in New South Wales, Australia

A project which sets out to explore alternative methods of regionalisation for prediction ofstreamflow in ungauged catchments is described. A commonly applied regionalisation methodology estimatesmodel parameters for the ungauged basin from multiple linear regressions between parameters and catchmentattributes, calibrated on gauged catchments. Its effectiveness is limited by the availability of sufficientlysimilar, well gauged and modelled catchments. In this paper a different approach is adopted, employing a datamining methodology to seek a useful set of rules in the catchment attribute space with parameter values asconsequent. The outline of a hypothesis testing algorithm is given, along with a suggestion for a newdiscretisation method. The techniques are both based on the information theoretic concepts of cross entropyand mutual information.