Paving the Way for Climate-Resilient Infrastructure - UN CC:Learn

Chapter 7: A Framework for Risk Assessment and Risk-Informed Decision-Making for Infrastructure DevelopmentRepresenting the systemRisk management utilizes models that apply experiences of the private sector and expertise of scienceto make predictions about the real world. These models are based on observable indicators of exposure(i.e. events), vulnerability (associated with constituent failure events and direct consequences) and robustness(associated with indirect consequence), and are influenced by risk reduction measures (i.e. actions).Consistent with Bayesian probability theory, these real-world indicators provide valuable informationconcerning risks (i.e. probable losses) of a given system for improved decision-making.The three primary indicators of risk — exposure, vulnerability and robustness — contribute to the generationof consequences within the risk management framework. An exposure event (e.g. tropical cyclone,earthquake, or volcanic eruption) stimulates a system change. Based on the vulnerability and robustnessof the system, change in the physical system can lead to two types of event-imposed consequences: directand indirect consequences (see Figure 7.4).Figure 7.4: The generation of consequences from exposure, vulnerability and robustnessDirect consequences depend on vulnerability of the system and do not alone impede performance ofthe system. These physical impacts, such as loss of a house or impairment to a bridge, though damaging,can typically be repaired and do not necessarily result in system failure. The less vulnerable a system is, thefewer the direct consequences.Indirect consequences due to system change depend on the robustness of the system and are related todecreases in the system capacity. These event-imposed consequences, such as decreased functionality ofthe network, result in reduction of economical output of the societies where direct losses occur.84Paving the Way for Climate-Resilient Infrastructure: Conference Proceedings