Groundwater-induced flooding, a rare phenomenon that is increasing in low-elevation coastal cities due to higher water tables, is often neglected in flood risk mapping due to its sporadic frequency and considerably lower severity with respect to other flood hazards. A loosely coupled flood model is used to simulate the interplay between surface and subsurface flooding mechanisms simultaneously. This work opens new horizons on the development of compound flood models from a holistic perspective.

In this work, we proposed a multi-source data assimilation framework for near-real-time flood mapping. We used a quasi-2D hydraulic model to update model states by injecting both stage gauge observations and satellite-derived flood extents. Results showed improvements in terms of water level prediction and reduction of flood extent uncertainty when assimilating both stage gauges and satellite images with respect to the disjoint assimilation of both observations.

Floods may affect critical infrastructure which provides essential services to people. We analyse the impact of floods on road networks and water supply systems, and we investigate how cascade effects propagate if interdependencies among networks are not considered. The analysis shows that if preparedness plans include information on accessibility to key sections of water supply plants, less people suffer from water shortage in case of flood. The method is tested in the city of Florence (Italy).

Flood risk management requires a realistic estimation of flood losses. However, the capacity of available flood damage models to depict real damages is questionable. With a joint effort of eight research groups, the objective of this study was to compare the performances of nine models for the estimation of flood damage to buildings. The comparison provided more objective insights on the transferability of the models and on the reliability of their estimations.

Floods cause damage to people, buildings and infrastructures. Due to their usual location near rivers, water utilities are particularly exposed; in case of flood, the inundation of the facility can damage equipment and cause power outages. Such impact lead to costly repairs and disruption of service affecting indirectly people outside the inundated area. In this work a method to estimate the impact of floods on a water distribution system is introduced and applied to a case study.