Societal Impacts of Infrastructure Failure Interdependencies: Building an Empirical Knowledge Base

This paper discusses recent efforts to gather and synthesize empirical data on the societal impacts of infrastructure failure interdependencies (IFIs). A systematic database has been developed on IFIs and their social, economic, health, safety, and environmental consequences. Data pertain to several events, including the August 14, 2003 blackout (affecting the northeastern U.S. and eastern Canada), the 1998 Quebec ice storm, and three 2004 Florida hurricanes. The database emphasizes IFIs deriving from electric power disruptions. Data are drawn primarily from print/text media reports. Verification exercises are conducted against various other primary and secondary information sources. The database is used to comparatively assess patterns in the severity of societal consequences from IFIs, including characterizing hazard, infrastructure sectors, and impact types according to their "intensive" or "extensive" nature. Hurricanes and ice storms are found to be more similar to each other than to blackouts. Infrastructure sectors of greatest concern include transportation and utilities. Specific IFIs are identified that frequently occur and cause significant societal impacts. These results provide a basis for considering priorities for risk mitigation.