At the beginning of the project, a thematic committee was set up to structure the project and to ensure that it was in line with the governmental guidelines regarding flooding. These guidelines namely included the protection of people, the mitigation of damages to material goods and the protection of natural ecosystem functions.
The first step in the process was to identify scientific literature and expert knowledge in order to establish and weight the prioritization criteria with the project team. A hierarchical structure with four core components and a range of sub-components and criteria was selected. These core components are the elements of risk established in the literature:
- Historical consequences
Based on historical data, the “risk” component allows us to validate the occurrence of flooding risk for each watershed. The notion of vulnerability is often associated with the sensitivity and readiness of the natural and humanized territory to suffer damage. The “historical consequences” component quantifies the actual impacts of past floods. Finally, measures to mitigate risks and improve community capacities to cope with the risk are reflected in the “resilience” component.
Furthermore, the approach required defining the concept of flooding that would be used, since it implies not only the natural phenomenon of a flood, but also its occasional impact on the humanized environment. According to the Ministry of Public Safety (MPS), flood risk is defined as the probability that a natural or man-made phenomenon or risk will occur in an area where material and human issues are present. The flood risk is therefore the product of the natural hazard itself (the flood), but also of the sensitivity of the issues that may be affected by this risk.