Classical hydraulic approaches of urban floods do not consider flow exchanges between streets and buildings, which might be introducing a bias in the estimation of property damage. Using coupled hydraulic-economic models we analyze the effect of considering porous buildings in the assessment of material damage at a district level. Our results show potentially significant differences in flood damage when using porous buildings in comparison with more classic approaches.

It is impossible to protect all issues against flood risk. To prioritise protection, economic analyses are conducted. The French Ministry of the Environment wanted to make available damage functions that we have developed for several sectors. For this, we propose a methodological framework and apply it to the model we have developed to assess damage to agriculture. This improves the description, validation, transferability and updatability of models based on expert knowledge.

Estimating flood damage, although crucial for assessing flood risk and for designing mitigation policies, continues to face numerous challenges, notably the assessment of indirect damage. We focus on flood damage induced by the interactions between economic activities. By modeling the production processes of a cooperative wine-making system, we show that these interactions are important depending on their spatial and temporal characteristics.

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.

To limit the losses due to floods, people can adopt measures to protect their dwellings. We assessed the cost and efficacy of such measures using computer modelling. We found that the benefits of most of the measures studied are unlikely to exceed their cost when they are taken in dwellings that are not exposed to frequent floods (probability of occurrence of less than 1 / 100 per year). It is also often less expensive to use building materials adapted to floods than other common materials.