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Satoru Nishikawa

Nagoya University

Breakout Room 4.


Perception; Exposure; Landuse; Statistics; Incentive

How can the human dimensions of disaster impacts be more accurately captured and represented in the analysis, modeling and simulation of disasters?

Disasters can be described as a conjunction of hazard; vulnerability and exposure. Substantial progress has been made in scientific analysis of hazard phenomena. Also; progress in developing engineered structures contributes to decreasing vulnerability. However; vulnerability has huge human factors. Let us take an example of earthquake safety in an old house owned by a family in Tokyo. From a disaster reduction expert’s point of view; I would recommend the family to have a seismic inspection of the house; to see whether that house meets the latest seismic standards. If the house is found to be structurally fragile; I would recommend the house to be either retrofitted or rebuilt. Now will the family accept this recommendation and take action? There are several steps before they take action. First; one or more members of the family need to be concerned about earthquake safety. Also; they need to feel that an earthquake might hit them within their lifetime. Further; they need to sincerely feel that they do not want to die or be injured by future earthquakes; and more. This is a matter of risk perception. Exposure is mostly human factors. Thanks to the progress in numerical simulation based on hydrology; flood inundation hazard maps are widely published. But we know that many new houses are built in possible inundation zones. This is a matter of risk perception. How individuals perceive risks and how a group takes action is a huge factor in each disaster case. However; this area is still to be addressed.

What type of data and supporting research infrastructure would be necessary to enable novel, transdisciplinary approaches to answering these and other human-centered disaster questions?

We do not have basic statistical database on deaths and injuries by age; sex; and by location on each disaster events covering all Japan. For a limited number of big disasters; detailed case studies are conducted. But their methodology differs by the researcher group’s focus; and comparisons among disaster cases are not commonly conducted. I guess the same is in the USA. Such a basic statistical database would be necessary. Behaviors of individuals; behaviors of families; behaviors of small companies; behaviors of large companies; behaviors of non-profit organizations etc.; against risks are the important factors in deciding whether a natural hazard turns into a disaster or not. Risk perception of individuals and as a group or an organization is the deciding factor in location of houses; factories; shops; i.e.; land use and exposure. We do not have enough accumulation of such data on behaviors of individuals and groups regarding disasters. There are limited case studies of how individuals or groups reacted in disasters; but we do not have sizable mass to extract some kind of common wisdom of crowds to be applied for reliable simulation of human behavior in crisis. In the field of public health; a  sizable mass of human data exists and is applied. If there can be a common repository of such data to be accumulated and compared; it would lead to progress in clarification of root causes of disasters. But there is a big barrier: protection of personal data. The key is how to overcome this challenge.

In what ways can US-Japan collaborations advance these questions in new and important ways?

Both Japan and the US are democratic countries with multiple layers of governments and free economy. The government sector has limited power to regulate people and their economic activities. Both countries have experiences of hurricanes/typhoons; tornadoes; earthquakes and volcanic eruptions. If there can be a systematic comparison of human behavior or group reaction to risk information and warnings; we may be able to extract hints for better ways to guide people and groups to take preventive action and react promptly to early warnings. If we can measure the effectiveness of policy incentives to guide individuals and groups to avoid risks and be resilient; through comparison of two countries; I believe this will be a big contribution to disaster risk reduction.

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