Floods affected not only buildings and infratructure but also traffic infrastructure. This infrastructure is organized as a network or as a multi-layer network. If floods affect individual road and railway segments, the disruption of the traffic in these segments cascades throughout major parts of the network. Hence, transportation networks exhibit a systemic vulnerability. The main research question of this project is how floods disrupt the functioning of the transportation network as a whole. We are developing routines and metrics to estimate and quantify the vulnerability of network infrastructure. The main challenge is to merge simulation approaches with network analysis approaches. Our analysis allows to identify cities and villages that will be pivotal during the flooding by providing critical services such as hospitalization services, food supply, etc. throughout a flood event. Moreover, we analyse the loss of emergency services due to traffic interruptions. This approach is particularly relevant for practical risk management and will help decision makers for allocating resources in space and time.