Assessing resilience of urban lifeline networks to intentional attacks

Abstract

Lifeline networks are critical to urban economies and societies. Resilience is an emerging concept for analyzing the dynamic performances of critical infrastructures impacted by natural hazards or attacks. Although many studies have examined how to assess the resilience of lifeline networks to natural disasters, very few have investigated resilience to intentional attacks. This study presents a framework for assessing the resilience of urban lifeline networks to intentional attacks. Using a game-theoretic model, this framework can firstly predict the most likely strategies of both the attacker and defender at Nash equilibrium as the preconditions for resilience assessment. Then a new feature ‘degree of recovery’ is proposed to quantify differences in network's performance (pre-attack vs. post-recovery). The framework also integrates a requirement for functional characteristics in designing the performance response function of lifeline networks. In the case study of IEEE 30-bus network, the most likely strategies of attacker and defender at Nash equilibrium were figured out. Then the resilience of network was assessed and thoroughly discussed. The results showed that the recovery resource and budget had different effects on the resilience. Furthermore, it was demonstrated how the assessment framework can provide a quick reference tool for optimal decision-making under various scenarios.