The analysis of ruptures in metropolitan gas pipelines

We model the yearly counts of occurred ruptures in a metropolitan gas distribution network using both a homogeneous Poisson process and a power law process. Covariates such as depth, diameter and site of the pipes are included via standard generalised linear modelling for Poisson data in the first case and via a proportional intensity function in the second case. It is found that the homogeneous Poisson process provides an acceptable interpretation of the data, thus confirming the hypothesis that the cast iron pipes do not suffer from erosion and that only the traffic condition on the site above the pipes seem to affect the rupture rate.