Logistic pipe failure prediction models for an urban water distribution network in the developing world: a case study of Kampala water, Uganda

Abstract

Statistical models can be used as proactive approaches to pipe failure management for the satisfactory and efficient functionality of a water distribution network (WDN). The study aimed to develop two logistic regression models using historical data and evaluated them based on prediction accuracy, receiver operator characteristics (ROC), and area under the curve (AUC). Pipe sizes ranging from 150 mm to 350 mm in the WDN were adequate to prevent pipe failure. However, a 250 mm pipe diameter had the lowest failure probability. Old pipes had a lower failure probability than new pipes. Although it was evident that the installation design of water pipes is changing from steel to unplasticized polyvinyl chloride (uPVC), steel pipes had a lower failure probability than uPVC at the same depth from the soil surface. Pipes buried in gravel with a small diameter had a lower failure probability than those in clay of a bigger diameter. With a median pipe age of 8 years in the WDN and greater class weight on pipe failures, the binomial logistic regression model had better performance (accuracy – 96.9%, AUC – 0.996) than the multinomial logistic model (accuracy – 90.9%, AUC – 0.992), representing reliable model predictions. The models can be used to modify data collection protocols to better identify potential water pipes that require maintenance or replacement. HIGHLIGHTS Pipe failure is intricate and depends on physical, environmental, and operational pipe attributes.; 250-mm pipe diameter had the lowest failure probability.; Old pipes have a lower failure probability than new pipes.; Pipes with low population density had a higher failure probability than those in densely populated areas.; Binomial logistic regression model had better performance than the multinomial logistic model.;

Keywords

• failure frequency
• logistic regression
• model
• prediction
• water distribution
• water mains replacement