Developing resilience to naturally triggered disasters

Abstract

Naturally triggered disasters are serious disruptions to society resulting from complex interactions between natural and human systems. Probabilistically based risk management is intrinsically unreliable for planning local (or community) resilience to naturally triggered disasters, because the number of such events that will affect a given community in any realistic planning time frame is very small, so event occurrence is unlikely to reliably match probability, and because even with small discrepancies between probability and occurrence, utility optimisation compounds these to yield optima with very large imprecisions. Thus, probabilistically based risk management is only applicable reliably to disaster reduction that considers large numbers of events, for example, when governments are performing their mandated duties around regional or national public safety and when insurance companies are analysing disaster statistics across large areas. This leaves a methodology gap for disaster reduction at local scale, which puts in question the validity of larger-scale strategies to reduce disaster impacts. Complex system science suggests that disasters are fundamentally unpredictable; certainly, they are often unexpected when they occur. Disaster risk reduction/management identifies the need to “Identify, assess and monitor disaster risks…”; but because disaster triggers are generally poorly quantified, or unexpected in type or magnitude, this is an unrealistic aspiration. An alternative strategy, for developing community resilience to disaster effects scenarios, is suggested herein, as a complement to conventional risk management applied over larger areas. Communities can increase their resilience by engaging with scientists and officials to develop realistic disaster event and effects scenarios and then to plan how the effects scenarios can be reduced, by adapting community behaviour and structure as opportunities arise. This can then underpin and link to larger-scale disaster reduction strategies. Systems that exhibit resilience to system shocks have structures and behaviours that appear to correspond to the characteristics of complex dynamic systems. However, modern societal behaviours deviate from these, and strategies for improving resilience to naturally triggered disasters may be indicated by complex system behaviour.

Appendix: Definitions (http://www.unisdr.org/we/inform/terminology)

1.1 Disaster

A serious disruption of the functioning of a community or a society involving widespread human, material, economic or environmental losses and impacts, which exceeds the ability of the affected community or society to cope using its own resources.

Comment Disasters are often described as a result of the combination of: the exposure to a hazard; the conditions of vulnerability that are present; and insufficient capacity or measures to reduce or cope with the potential negative consequences. Disaster impacts may include loss of life, injury, disease and other negative effects on human physical, mental and social well-being, together with damage to property, destruction of assets, loss of services, social and economic disruption and environmental degradation.

30 Aug 2007

1.2 Disaster risk

The potential disaster losses, in lives, health status, livelihoods, assets and services, which could occur to a particular community or a society over some specified future time period.

Comment The definition of disaster risk reflects the concept of disasters as the outcome of continuously present conditions of risk. Disaster risk comprises different types of potential losses which are often difficult to quantify. Nevertheless, with knowledge of the prevailing hazards and the patterns of population and socio-economic development, disaster risks can be assessed and mapped, in broad terms at least.

23 Jan 2009

1.3 Disaster risk management

The systematic process of using administrative directives, organisations, and operational skills and capacities to implement strategies, policies and improved coping capacities in order to lessen the adverse impacts of hazards and the possibility of disaster.

Comment This term is an extension of the more general term “risk management” to address the specific issue of disaster risks. Disaster risk management aims to avoid, lessen or transfer the adverse effects of hazards through activities and measures for prevention, mitigation and preparedness.

30 Aug 2007

1.4 Disaster risk reduction

The concept and practice of reducing disaster risks through systematic efforts to analyse and manage the causal factors of disasters, including through reduced exposure to hazards, lessened vulnerability of people and property, wise management of land and the environment and improved preparedness for adverse events.

Comment A comprehensive approach to reduce disaster risks is set out in the United Nations-endorsed Hyogo Framework for Action, adopted in 2005, whose expected outcome is “The substantial reduction in disaster losses, in lives and the social, economic and environmental assets of communities and countries.” The International Strategy for Disaster Reduction (ISDR) system provides a vehicle for cooperation among Governments, organisations and civil society actors to assist in the implementation of the Framework. Note that while the term “disaster reduction” is sometimes used, the term “disaster risk reduction” provides a better recognition of the ongoing nature of disaster risks and the ongoing potential to reduce these risks.

30 Aug 2007

1.5 Risk

The combination of the probability of an event and its negative consequences.

Comment This definition closely follows the definition of the ISO/IEC Guide 73. The word “risk” has two distinctive connotations: in popular usage, the emphasis is usually placed on the concept of chance or possibility, such as in “the risk of an accident”, whereas in technical settings, the emphasis is usually placed on the consequences, in terms of “potential losses” for some particular cause, place and period. It can be noted that people do not necessarily share the same perceptions of the significance and underlying causes of different risks.

See other risk-related terms in the Terminology: Acceptable risk; Corrective disaster risk management; Disaster risk; Disaster risk management; Disaster risk reduction; Disaster risk reduction plans; Extensive risk; Intensive risk; Prospective disaster risk management; Residual risk; Risk assessment; Risk management; Risk transfer.

30 Aug 2007