Chapter 22 - Multihazard analyses and their implications for the defense of society against natural phenomena

Abstract

The Sendai Framework for Disaster Risk Reduction (2015–30) calls for incorporating science into the policy process. However, this carries the risk of politicizing science, and therefore, may blur the boundaries of the roles of the different risk management actors. These difficulties are aggravated in the context of an emergency or natural disaster, where scientists advise the authorities. In these situations, decision-makers need to respond with the utmost precision to three basic questions: (1) what phenomena will occur, (2) when will they occur, and (3) where will they impact? Despite the efforts of the scientific community to conduct increasingly accurate studies on natural events, uncertainty is often high and/or unavoidable. This uncertainty, in an environment of pressure, urgency, and ineffective communication, can lead to the proliferation of nonconsensual, incomprehensible, misunderstood, and erroneous information. In an extreme case, it can even aggravate the impact of such a natural disaster (e.g., L'Aquila earthquake in 2009). On the other hand, in a context of climate change—where the magnitude and frequency of many events are increasing—and unstoppable demographic expansion, the trend is toward greater risk. Moreover, the appearance of increasingly complex and strong relationships between different types of events, with the occurrence of concatenations and cascading effects, increases uncertainty, and therefore makes it difficult to design strategies for prevention, action, and recovery. Multihazard analyses can help to reduce this uncertainty in the complex scenarios that are plaguing society today and will continue to do in the future. Multihazard analyses are a first step toward a transdisciplinary, cross-sectoral, and cross-border multirisk management plan that is based on scientific knowledge. The greater precision of risk estimation will contribute to better supporting decision-makers, thus implying the ethical communication of information that reduces misunderstanding, thereby contributing to the resilience of societies.