Resilience and Sustainability in Relation to Natural Disasters
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Natural Hazard Science. Please check back later for the full article.
Increasing complexity of cities, along with the alarming rate of the occurrence of severe natural disasters, is now recognized as one of the main global issues affecting the quality of human life and environmental safety. Accordingly, a feasible approach aimed at managing the urban and global environment is urgently needed, and, in this regard, sustainable development is the solution.
A sustainable process is a set of actions aimed at ensuring the well-being of both current and future generations. It is implemented with a view to governing the two main complex systems that constitute the urban fabric: the first includes man and society, and the second the environment and natural resources, with the two systems interrelated by dynamic, and sometimes also conflicting, relationships.
Nowadays, achieving the sustainability of urban environments is an ambitious challenge from both a local (i.e., land, community, and local resource management) and a global perspective (i.e., energy and financial use efficiency, societal development, and human well-being). In this regard, communities have to cope with natural disasters by addressing mitigation, adaptation, emergency management, and recovery actions in a conscientious and efficient manner. As a consequence, a focal, comprehensive objective—that communities can pursue to ensure future sustainable cities that are able to cope with the risks they are exposed to—is related to urban resilience.
Essentially, resilience is defined as the capability of cities and communities to withstand major unexpected events and to recover in a functional and efficient manner. Accordingly, in an urban context, resilience should be guaranteed to ensure the sustainability of processes in both peace time and cases of disaster.
The same definition of resilience implies that a wide and highly diversified range of factors and intrinsic dynamics are accounted for, which requires a multi-scale approach: from the single building level to the urban and, ultimately, the global environmental scale.
Moreover, when shifting the focus from the single structure to the single city scale, human behavior is revealed as a very critical factor. This is because social actors behave and make choices every day in an unpredictable and unorganized manner that affects city functioning. In this sense, urban complexity can be addressed through the ecosystem theory approach, which accounts for interrelations between physical and human components. As a consequence, cities can be understood as physical systems, assessed through engineering metrics; yet contextually, they can be studied according to a human-centric perspective.
On this scale, resilience can be understood as the potential of the complex city system to overcome a catastrophic event that affects its built environment and, consequently, the citizens using it, while also ensuring social, economic, and environmental sustainability. This perspective enables resilience to be defined in two different ways: the ecosystem approach, which considers the complex urban nature; and the engineering perspective, which enables the rigorous quantification of resilience. In this article, the two meanings are merged, and engineering resilience is defined according to ecosystem theory, namely the capability of complex systems to withstand external stress and bounce back to an equilibrium state, which can be the same as the pre-event state or a new condition.