A methodological approach for mapping and analysing cascading effects of flooding events

ABSTRACT

Current local or regional flood risk assessments, as required by the EU flood risk directive, rarely account for cascading effects due to interdependencies between critical infrastructures. However, it is essential to consider these effects, as they may severely impact areas outside the immediate flood risk area. The main purpose is to present and problematize a method (AB-CEM) for mapping and analysing cascading effects due to floods, aiming at also being relevant for other spatially widespread hazards. The method development and the pilot study, in Sweden, reveal that there is a prominent practical need for methods for mapping and analysing critical infrastructure interdependencies and cascading effects. Another key finding is that the method process and its results can serve as an important basis for decision-making about proactive and reactive efforts related to geographically extensive hazards. We further conclude that there is a recurring problem regarding sensitive and secret data. More specifically, the conflicting interests of information availability and information security concerning critical infrastructures, which needs to be resolved at the national level and communicated through clear guidelines. The method is a much-needed step towards accounting for cascading effects of floods in practice.

KEYWORDS:

• Cascading effects
• flood risk assessment
• critical infrastructure
• interdependencies
• GIS
• Sweden
• flood directive

Acknowledgements

The Swedish Civil Contingencies Agency provided the funding enabling the presented research through the Centre for Critical Infrastructure Protection Research (CenCIP); their support is greatly acknowledged. The authors further extend gratitude to all the involved stakeholders for providing crucial insights and support for the development and evaluation of the method. Lastly, we wish to thank Emma Andersson and Daniel Carlström for performing the pilot study using AB-CEM as a part of their master thesis in risk and safety management.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Myndigheten för Samhällsskydd och Beredskap.