Portmanteau Procedure for Model-Fit Evaluation

Theoretic concepts of basic Shannonian information are discussed with special reference to the setting up of relatively simple small-scale computational hydraulics models. It is argued that often the relative mutual information between two distributions, I(X; Y)/S(X), may be a simple, versatile, robust, and approximately consistent quantitative estimate of the degree of fit between measurements (X distribution) and model results (Y distribution). It is proposed that the quantity be named the confluence, ?, and test results are presented in support of its practical utility.