Risk and Vulnerability Analysis of Interdependent Technical Infrastructures

Reliable electrical power supply is a prerequisite for the modernsociety, and if it fails, it can cause severe consequences in terms of economiclosses and even fatalities. It is thus important to analyse the vulnerabilityof the electric power system. Network analysis has previously been used toanalyse the vulnerability of electric transmission systems. Recent events inSweden, however, have shown that perturbations in distribution systems canalso cause severe societal consequences. Thus, we argue that vulnerabilityanalysis at the distribution level is equally important. Furthermore, previouswork has focused on the technical aspects of the system, and in this paper wetake a step towards incorporating the societal aspects of vulnerability bysuggesting new network analytic measures. We analyse the distribution systemsin two Swedish municipalities using the proposed measures. We conclude thatthe proposed measures can increase the value of using network analysis whenanalysing societal vulnerability to perturbations in electric distribution systemsand that such analysis also can be useful in emergency mitigation andpreparedness planning.