Understanding Extreme Geohazards: The Science of the Disaster Risk Management Cycle

European Science Foundation Conference
November 28 to December 1, 2011, Sant Feliu de Guixols, Spain

Session 2 “Session 4: Predicting increased risks for extreme hazards: earthquakes.”

Discussion: “Towards a time-variable view on probability”

Alik Ismail-Zadeh: Costs of preparation versus costs of disaster (or how to break a seismo-illogical cycle?)

Scientists knew about historical devastating earthquakes and tsunamis, such as those, which occurred in the Indian Ocean region, in Himalayas, Tibet, and the Japanese islands. Did it help to mitigate humanitarian disasters caused by extreme geohazard events in the 21st century?

Time is an important variable in natural disaster management, especially when it concerns extreme events. An extreme seismic event, in general, cannot be predicted in full details. So far, seismology can put confidence limits on uncertainty, although the limits are very wide in terms of the time, place and magnitude of an anticipated earthquake, which gives insufficient information for disaster management. Nevertheless hazard preparedness is vital for society. The less often natural events occur (and the extreme magnitude events are rare by definition), the more often disaster managers postpone preparedness for the events.

Ismail-Zadeh and Takeuchi (2007) wrote: “The tendency to reduce the funding for preventive disaster management of natural catastrophes rarely follows the rules of responsible stewardship for future generations neither in developing countries nor in highly developed economies”. The investment to avoid losses tends not to be easily accepted in political decision-making (due to a short life of governments-in-office) as compared with that to gain positive benefits. It is because the benefit of preventing losses, however long lasting it is, is not easily visible while the positive benefit is obvious and can easily be agreed by people.

A large investment is made, when a big disaster due to an earthquake occurs, and the investment decreases till the next large earthquake (see the figure below). If about 5 to 10% of the funds, necessary for recovery and rehabilitation after a disaster, would be spent to mitigate an anticipated earthquake, it could in effect save lives, constructions, and other resources. The reaction of media and the societal attention to disasters follow the same cycle. I call this cycle the “seismo-illogical cycle” meaning that a large investment is made when a big earthquake disaster occurs and the investment decreases till the next disaster occurs. If a seismic cycle is marked by an increase of tectonic stresses toward an earthquake (stress drop), the “seismo-illogical cycle” is characterised by a decrease of funding toward the next large seismic event.

How to break the seismo-illogical cycle?

How to convince disaster-management authorities paying forward, in advance of extreme events, to mitigate or even to prevent in some cases inflicting humanitarian disasters?

What is the role of geoscientists in preventive disaster management of catastrophic events?