Aqua (Mar 2024)
Identifying failure types in cyber-physical water distribution networks using machine learning models
Abstract
Water cyber-physical systems (CPSs) have experienced anomalies from cyber-physical attacks as well as conventional physical and operational failures (e.g., pipe leaks/bursts). In this regard, rapidly distinguishing and identifying a facing failure event from other possible failure events is necessary to take rapid emergency and recovery actions and, in turn, strengthen system's resilience. This paper investigated the performance of machine learning classification models – support vector machine (SVM), random forest (RF), and artificial neural networks (ANNs) – to differentiate and identify failure events that can occur in a water distribution network (WDN). Datasets for model features related to tank water levels, nodal pressure, and water flow of pumps and valves were produced using hydraulic model simulation (WNTR and epanetCPA tools) for C-Town WDN under pipe leaks/bursts, cyber-attacks, and physical attacks. The evaluation of accuracy, precision, recall, and F1-score for the three models in failure type identification showed the variation of their performances depending on the specific failure types and data noise levels. Based on the findings, this study discussed insights into building a framework consisting of multiple classification models, rather than relying on a single best-performing model, for the reliable classification and identification of failure types in WDNs. HIGHLIGHTS Further investigation for anomaly detection machine learning models in identifying a specific failure type is needed for WDN resilience.; Machine learning models showed reliable failure identification performance.; The models’ performance varied with the failure types and data noise levels.; The models produced misclassification between different failure events that produced similar hydraulic responses.; Insights into a framework with multiple classification models were discussed to improve the reliable failure identification of WDNs.;
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