Flood indirect impacts assessment: A systematic review of models and empirical literature

Floods are among the most frequent and costliest natural hazards worldwide and the associated human and economic losses are expected to increase due to climate change, urbanization and population growth. Therefore, it is crucial to develop a comprehensive understanding of the economic impacts of these disasters on our interconnected society. This should include the indirect impacts (e.g. business interruption, service disruption, cascading effects), which have been very often overlooked, especially in engineering works.

For this reason, this study reviews the recent scientific literature in the fields of economy and engineering on the socio-economic impacts of floods to derive the current state-of-the-art of the indirect impacts estimation. Given the complexity of the problem, it is necessary to integrate economic theory studies, which in general tend to focus on flow losses, and civil engineering studies, which, on the other hand, have centred their attention mainly on stock losses.

The different frameworks, methodologies and empirical studies are analysed through a systematic qualitative and quantitative review. The published articles are derived from well-known scientific database by setting indicators and keywords.

The results highlight the different sectors (e.g. economic sectors, firms, transportation system) and the different metrics (e.g. monetary values, time, space), adopted to quantify the indirect impacts, as well as the different purposes (e.g. risk assessment, risk management) of each study.

This work derives the current knowledge on the estimation of indirect impacts of flooding to provide clarity on the different perspectives of indirect impacts. Moreover, the findings can help to underline key gaps in the existing scientific literature and to indicate future research work.