Systemic seismic risk assessment of urban healthcare system considering interdependencies to critical infrastructures

Abstract

The performance of healthcare and other emergency systems, like firefighting, is of utmost importance in the aftermath of natural disasters such as seismic events. However, previous studies have often overlooked the interconnectedness of emergency systems to other critical infrastructures. In reality, the performance of the healthcare system does not only rely on the vulnerability of hospital buildings, but also on the vulnerability and performance of interdependent critical infrastructures, such as the transportation system for the accessibility of injured people to hospitals from the damaged sites or the continuous supply of water and electricity for the uninterrupted operation of hospital facilities. These interdependencies can significantly impact the overall emergency response effectiveness and is vital to consider them in the design and assessment of healthcare systems to safeguard resilience of the community. This study proposes a comprehensive methodological framework and associated metrics for evaluating and mapping the healthcare system's performance considering its interdependencies with other critical infrastructures. It encompasses hazard characterization, risk assessment at both component and system levels, and network-based analysis with conditional branching to account for first and second order interdependencies. The proposed framework is applied to the healthcare system of Thessaloniki, Greece. The operational tool and insights can help to prioritize ex-ante investments and identify ex-post intervention measures, ensuring an emergency response system on an urban scale within a resilient systemic perspective. Its applicability can be extended to address a spectrum of other hazards and interdependencies at urban and regional scales, to ensure peoples' safety and minimize socioeconomic losses.