Sustainable Infrastructure Subjected to Multiple Threats

Critical infrastructure systems provide a foundation for socio-economic stability, national security, and quality of life. Their performance is continuously threatened by an array of hazards, while insufficient physical performance can have cascading social, environmental, and economic consequences. This paper frames the various threats to sustainable infrastructure and summarizes the state of the art for measuring sustainable performance with indicators. A risk based paradigm of "engineering sustainable infrastructure against threats" is presented. Threats considered include aging and deterioration, population growth and urbanization, natural hazards and climate change. Performance measures of sustainable systems challenged by these threats span the three core areas of sustainable engineering including social, environmental, and economic impacts, such as safety, energy usage, and life-cycle cost. A simple application is provided for bridge infrastructure systems located in seismic zones. This paper illustrates the critical link that the natural hazards and risk assessment community can play in developing strategies to select and promote sustainable lifeline systems.