The impact of pipe segment length on break predictions in water distribution systems

Break prediction models are important tools in asset management and rehabilitation planning of water distribution systems. To some extent though, they may depend on the configuration of the network as defined in the company database. This paper examines the effect of the length of pipe segments on break predictions and proposes methods for eliminating short sections of pipe sandwiched between longer pipes and for concatenating segments of the same (or similar) nature. A study was conducted on a large French network using a set of rules and length threshold values to prepare several different data files. These data files, containing the pipes' attribute information and associated break histories were used with the statistical model, LEYP, to make break predictions for each segment. The results were compared using a number of indicators. Ultimately, there would appear to be little benefit in concatenation as the model is likely to become less sensitive and less able to distinguish between risk factors.