On‐Line Warning System for Pipe Burst Using Bayesian Dynamic Linear Models

• Published in: Water resources research Vol. 59; no. 4
• Main Authors: Henriques‐Silva, Renato, Duchesne, Sophie, St‐Gelais, Nicolas Fortin, Saran, Naysan, Schmidt, Alexandra M.
• Format: Journal Article
• Language: English
• Published: 01.04.2023
• Subjects: Bayes' factor; outlier detection; time series analysis; water flow
• ISSN: 0043-1397; 1944-7973
• DOI: 10.1029/2021WR031745

Pipe breaks are a recurrent problem in water distribution networks and detecting them quickly is crucial to minimize the economic and environmental costs for municipalities. This study presents a burst detection methodology applying Bayesian dynamic linear models (DLMs) on water flow time series combined with an outlier monitoring tool. The model is used to characterize the actual flow and, for each time, a one‐step ahead forecast distribution is obtained recursively before moving onto the next observation. The outlier detection method consists of comparing the main model with an alternative one wherein the mean flow is shifted to a higher value (as bursts tend to increase flow) to evaluate which model best fit the observed data. If the alternative model is favored, a burst alarm is issued. To verify the performance of this approach, the DLM and monitoring tool were applied on 2 yr of flow data from two district meter areas (DMAs) in Halifax (Canada), and a historical break data set is used to assess model accuracy. The model was able to detect up to 75% and 71.2% of the pipe breaks, with a false alarm rate of 5.15% and 12% in the first and second DMA, respectively. Finally, the proposed model allows for straightforward interpretation of model parameters, nonlinear relationship between flow and predictors of interest, naturally describes the uncertainty for future predictions, can easily accommodate missing values and can be tuned to maximize break detection or minimize false alarm rates to adapt to specific objectives of water infrastructure managers. Key Points A Bayesian dynamic linear model is developed to detect pipe burst by modeling flow time series and monitoring outliers The model naturally accommodates nonlinear associations between flow and predictors (e.g., pressure, temperature) Non‐stationarity of the flow time series is naturally accounted for through the dynamic structure of the parameters in the model