Toward Improved Understanding Of Warnings For Short-Fuse Weather Events

点击翻译按钮获取中文摘要

INPUT-OUTPUT RISK MODEL OF CRITICAL INFRASTRUCTURE SYSTEMS There is no higher priority for the nation today than assuring the security, continuity, and availability of our critical infrastructures. Modern critical infrastructures are marked by immense complexity, and characterized by strong intra- and interdependencies, as well as multiple hierarchies. The higher degree of interdependencies exhibited by our critical infrastructures-attributable in part to their increased reliance on modern technology-make them more vulnerable to human-caused disasters such as acts of terrorism. In assessing the vulnerability of a critical infrastructure, it is important to analyze not only an infrastructure per se but also its interconnectedness and influences on other infrastructures. Understanding this interconnectedness can be achieved by modeling the way inoperability propagates and proliferates throughout a critical system of infrastructures. Inoperability is defined as the inability of the system to perform its intended natural or engineered functions. Risk of inoperability is defined as a measure of the probability and the consequence expressed as a degree of the inoperability of the system. The research goal to develop a model capable of describing the risks inherent to our Nation's critical infrastructures will be realized primarily through extensions of an existing Leontief-based infrastructure inoperability model. Following are the components of the research effort: (1) Establish the theoretical bases underlying the concept of risk of inoperability, namely the mechanics by which inoperability can propagate through a system of interconnected infrastructures; (2) Develop a hierarchical implementation of the inoperability input-output risk model to address geographical and functional decomposition of the system of infrastructures; (3) Study the dynamics of inoperability due to an initial perturbation, addressing cascading effects of an attack in various temporal regimes (e.g., short-term, intermediate-term, or long-term); and (4) Provide a prototype application of the proposed inoperability I-O risk model to the electric power infrastructure. The inoperability I-O risk model developed here is an initial attempt to contribute to the incredible efforts needed to better our understanding of these dependencies, and subsequently to manage more cost-effectively the threats and risks that critical infrastructures encounter today. Thus, the proposed model is best viewed as a first step in an ambitious attempt to develop a more comprehensive risk assessment and management framework for ensuring the integrity and continued operability of the Nation's complex critical infrastructures.