Flood is a typical phenomenon that involves the human-water interactions. In socio-hydrology, which deals with the coevolution of water and society, the development of socio-hydrological models to represent the human-flood interaction has been progressing rapidly. The proposed model describes the interaction between floods, residential density, awareness, preparedness, and flood losses, and uses empirical data to estimate the parameters of the model (Di Baldassarre et. al., 2015). The data on flood awareness and preparedness are the most important for correctly estimating the parameters and modeling the system dynamics (Barendrecht et. al., 2019). It is assumed that flood awareness and preparedness vary from region to region depending on the sociodemographic characteristics and socio-hydrological context in the region. Therefore, comparative analysis of those parameters among different regions is absolutely necessary to properly understand and represent the socio-hydrological phenomena.
In this study, we conducted a questionnaire survey on flood awareness/preparedness, memory, and sociodemographic factors in Nagano City, a typical flood-prone area in Japan, which was also affected by the Typhoon Hagibis in 2019 (number of subjects: 1,000). And we clarified how these factors are related to sociodemographic characteristics, disaster experience, risk perception, and land attachment. Finally, we compare the several results of the survey with those conducted in the northeastern part of the Italian Alps, which was affected by mudslides in 2000 and 2002 (Scolobig et.al., 2012), and discuss the characteristics of human-water interaction in Japan.
Barendrecht, M. H., Viglione, A., Kreibich, H., Merz, B., Vorogushyn, S., & Blöschl, G. (2019). The value of empirical data for estimating the parameters of a sociohydrological flood risk model. Water Resour. Res., 55, 1312– 1336.
Di Baldassarre, G., Viglione, A., Carr, G., Kuil, L., Yan, K., Brandimarte, L., and Blöschl, G. (2015), Debates—Perspectives on socio-hydrology: Capturing feedbacks between physical and social processes, Water Resour. Res., 51, 4770– 4781.
Scolobig, A., De Marchi, B., and Borga, M., 2012. The missing link between flood risk awareness and preparedness: findings from case studies in an Alpine Region. Natural Hazards, 63 (2), 499–520.