Statistical analysis and definition of blockages-prediction formulae for the wastewater network of Oslo by evolutionary computing

Oslo Vann og Avløpsetaten (VAV) – the water/wastewater utility in the Norwegian capital city of Oslo – is assessing future strategies for selection of most reliable materials for wastewater networks, taking into account not only material technical performance but also material performance, regarding operational condition of the system. The research project undertaken by SINTEF, NTNU and Oslo VAV adopts several approaches to understand reasons for failures that may impact flow capacity, by analysing historical data for blockages in Oslo. The aim of the study was to understand whether there is a relationship between the performance of the pipeline and a number of specific attributes such as age, material, diameter, to name a few. This paper presents the characteristics of the data set available and discusses the results obtained by performing two different approaches: a traditional statistical analysis by segregating the pipes into cohorts, each of which with the same explanatory variables, and a Evolutionary Polynomial Regression model (EPR), developed by Technical University of Bari and University of Exeter, to identify possible influence of pipe’s attributes on the total amount of predicted blockages in a period of time.