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CLICCS
Cluster of ExcellenceClimate, Climatic Change,
and Society (CLICCS)

Photo: J.Marotzke/ M.Böttinger

Theme C

Conceptual Model

Towards a socio-ecological system understanding of urban flood risk and barriers to adaptation under climate change in the city of Hamburg

Cities are facing increasing challenges of flood risk due to the combined effects of climate change and socioeconomic development. Consequently, climate change adaptation is imperative for the protection of both citizens and assets. We developed a qualitative system dynamics modeling framework to holistically investigate urban flood risk under climate change and its challenging adaptation process in a coupled socio-ecological system using the city of Hamburg as a case study. Particular emphasis is placed on identifying and analyzing the dynamic feedback processes underlying the complex urban system in order to understand barriers to climate change adaptation.

Methodically, the study draws on the group model building approach of Vennix (1996) focusing on building system dynamics models with teams. This participatory qualitative modelling process was embedded in an interdisciplinary setting with researchers from 17 different disciplines. In fact, 13 group interviews were conducted to develop disciplinary mental maps representing different worldviews on the problem. Then, the partial mental maps were merged to an overall group model, and analyzed in terms of model behavior and dynamics.

The integrated model shows that the main drivers of urban flood risk growth in Hamburg are linked to socio-economic and institutional processes. Climate change mainly affects the city externally through increasing flood hazards contributing to flood risk. However, the city also internally contributes to flood risk through exposure and social vulnerability, and even amplifies flood risk through reinforcing dynamics. The results show that barriers to climate change adaptation in the city are linked to amplifying feedback loops.

Contact: Dr. Franziska S. Hanf (UHH)

Figure: Sketch of the merged conceptual model based on the disciplinary mental maps developed in the group interviews.

 

Related scientific C1 publications

Hanf, F.S., Ament, F., Boettcher, M., Burgemeister, F., Gaslikova, L., Hoffmann, P., Knieling, J., Matthias, V., Meier, L., Pein, J., Poschlod, B., Quante, M., Ratzke, L., Rudolph, E., Scheffran, J., Schlünzen, K. H., Shokri, N., Sillmann, J., Vogelbacher, A., von Szombathely, M., Wickel, M. (2025). Towards a socio-ecological system understanding of urban flood risk and barriers to climate change adaptation using causal loop diagrams. International Journal of Urban Sustainable Development, 17 (1), 69–102, https://doi.org/10.1080/19463138.2025.2474399.