Credits: @cristina_gottardi Unsplash

The extent of damages caused by floods also depends on how people prepare to face the risk but current methods do not take into account individual perception and human behavior. An international team of scientists including Director of CMCC RAAS Division Jaroslav Mysiak addresses the issue in a Perspective article published in Nature Climate Change.

What turns a natural event, such as a flood, into a disaster? What information must be taken into account to assess flood risk and arrange strategies and investments to reduce damages? According to a recent article published in Nature Climate Change “Integrating human behaviour dynamics into flood disaster risk assessment”, the behavior of individuals, companies and government agencies – before, during and after a flood – is a critical factor that can dramatically influence the impact. However, it is rarely considered.

“Existing models estimate the damage by taking into account the characteristics of a flood event, not the level of awareness and the behaviour of the population,” explains Jaroslav Mysiak, director of the RAAS division of CMCC and co-author of the study. “Factors such as flood depth, speed, content of transported sediments and debris, etc. are considered, but risk perception and the adoption of protection measures (such as whether to stipulate an insurance policy, or, more simply, the choice of where to park your car) are not”.

According to the authors, the next generation of flood-risk assessment models should integrate better knowledge of how people deal with risk and damage. A goal that implies a revolution in the methods and criteria used to identify and collect the necessary data.

“Collecting this kind of information does not represent a more difficult task in itself,” explains Mysiak. “The models we use to estimate structural damage are pretty much the same from decades ago. They have been refined, so we certainly have a better knowledge now, but the model structure has not changed much: it is a function that combines the characteristics of a flood event and the exposure in an observed area. Now we need a step change to improve these models and take individual responses to risk into account. It is not an impossible goal. It would require, for example, a series of surveys and forensic analyses to help us understand the response of the population, or of certain social groups. We need to change the way we study and interpret risk and to set up different data-collecting methods than in the past. ”

For more information, read the integral version of the paper:
Aerts J. C. J. H., Botzen W. J., Clarke K. C., Cutter S. L., Hall J. W., Merz B., Michel-Kerjan E., Mysiak J., Surminski S. and Kunreuther H.
Integrating human behaviour dynamics into flood disaster risk assessment
2018, Nature Climate Change, 8, 193–199, doi:10.1038/s41558-018-0085-1