Developing resilience to naturally triggered disasters

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.