Resource allocation, emergency response capability, and infrastructure concentration around vulnerable sites

Public and private decision-makers continue to seek risk-based approaches to allocate funds to help communities respond to disasters, accidents, and terrorist attacks involving critical infrastructure facilities. The requirements for emergency response capability depend both upon risks within a region's jurisdiction and mutual aid agreements that have been made with other regions. In general, regions in close proximity to infrastructure would benefit more from resources to improve preparedness because there is a greater potential for an event requiring emergency response to occur if there are more facilities at which such events could occur. Thus, a potentially important input into decisions about allocating funds for security is the proximity of a community to high concentrations of infrastructure systems that potentially could be at risk to an industrial accident, natural disaster, or terrorist attack. In this paper, we describe a methodology for measuring a region's exposure to infrastructure-related risks that captures both a community's concentration of facilities or sites considered to be vulnerable and of the proximity of these facilities to surrounding infrastructure systems. These measures are based on smoothing-based nonparametric probability density estimators, which are then used to estimate the probability of the entire infrastructure occurring within any specified distance of facilities in a county. The set of facilities used in the paper to illustrate the use of this methodology consists of facilities identified as vulnerable through the California Buffer Zone Protection Program. For infrastructure in surrounding areas we use dams judged to be high hazards, and BART tracks. The results show that the methodology provides information about patterns of critical infrastructure in regions that is relevant for decisions about how to allocate terrorism security and emergency preparedness resources.