Multi-attribute evaluation of flood management in Japan: a choice experiment approach

This paper intends to clarify the relationship among the important attributes of flood prevention measures and the effects of socio-economic factors on the public preferences of selecting the measures based on the choice experiment approach. The experiment was conducted via a mail survey in the Toki-Shonai River basin of central Japan. First, the relationships among the five attributes (external flood reduction, internal flood reduction, early warning systems, environmental protection and willingness to pay for such countermeasures) were quantitatively clarified, and it was shown that an early warning system in terms of fatality rate due to floods was lowly evaluated by the public. Second, certain socio-economic factors, like annual household income, flood experience, sex and distance to a river, had statistically significant impacts on the utility functions in our model. Third and finally, there was a statistically significant difference in regional model results between Toki city and Kita ward of Nagoya city. These results imply the necessity to implement localized watershed management in Japanese urban catchments, and to improve information provision and public understanding of flood risk.