Applications of discriminative flow pattern analysis using the CFPD method
Author: Peter van Thienen, Ilse Pieterse-Quirijns, Jan Vreeburg, Karel Vangeel, Zoran Kapelan
Several applications of a new method for flow pattern analysis called the Comparison of Flow Pattern Distributions (CFPD) are presented. This method allows the user to compare flow patterns of a supply area and distinguish consistent from inconsistent changes in them. The so-called consistent changes are mainly caused by modifications in the characteristics of the population. The so-called inconsistent changes are generally related to new large volume customers, new types of water use and/or changes in leakage. Detailed knowledge of the supply area allows quantitative statements to be made about leakage. The method presented here is simple, not computationally intensive, independent of any model assumptions and easily implemented. The automated application of this method on long time series, called CFPD block analysis, is applied on data from three different areas. These applications illustrate, respectively, the identification and pinpointing (in time) of a small leak, the independent quantification of concurrent different types of changes with opposite signs in a supply pattern, and the difficulties of interpretation in cases in which climate has an overwhelming influence on demand patterns. In each case, discriminative quantification and visualization by the CFPD method result in features and trends in complicated time series becoming apparent at a glance.