## 3 Results and Discussion
### Final AHP-GDM Weights  
The final AHP-GDM weights for the flood vulnerability criteria and sub-criteria (Figure 6) were obtained by aggregating the individual weights. The population criterion is the one that contributes more to the final vulnerability, followed by the building and exposed elements, the socio-economic criterion had the lower weight in the final vulnerability. Within the population criterion, the age structure sub-criterion contributes significantly to vulnerability, while gender contributes the least. The percentage of the population under 14, the percentage of the population between 14 and 65, and the percentage of households with more than five persons were considered the most relevant sub-criteria. Several studies indicate that the elderly have limited mobility and physical difficulties during an evacuation, are more reluctant to leave their homes, have health problems, and have a longer recovery time after the flood event [50]. Households with many relatives are also more likely to share income and have more dependents, such as children and the elderly, to evacuate [35], making them more vulnerable. The youngest also have high levels of physical vulnerability and dependency [34; 35; 36; 38]. For the building's criterion, the function and percentage of collective buildings are the sub-criteria with the higher contribution. Collective buildings can contribute to increased vulnerability because they present additional difficulties in the evacuation and resettlement  
Figure 5: Dispersion of individual expert’s weights for each criterion. The red line indicates the median, and the bottom and top edges of the box indicate the 25 th and 75 th percentiles, respectively. The whiskers extend to the most extreme data points not considered outliers, and the outliers are plotted individually using the plus red symbol. A black dot marks the final group weight for each criterion. Figure 6: Final criteria and sub-criteria AHP-GDM weights. process [51]. The percentage of buildings built before 1980, the percentage of buildings with one or two floors, and the percentage of buildings that are exclusively or mainly residential were considered to be the most relevant sub-criteria. Newer buildings are built according to stricter building safety regulations and should therefore be more resistant. Older neighbourhoods (usually in city centres and/or close to rivers) also have older sewerage systems, which contribute to higher flood vulnerability [39]. As the number of storeys increases, flood vulnerability decreases as upper storeys can protect people and their property [40]. The results showed that residential buildings contribute more to the vulnerability than non-residential buildings. A plausible explanation, which may vary from country to country depending on the insurance practices, relates to the fact that non-residential buildings are, in general, insured. For the socio-economic criterion, the four sub-criteria have a similar weight to the final social vulnerability. In the socio-economic criterion, the percentage of persons having completed junior high school and the percentage of rented dwellings were considered the most relevant sub-criteria. Educational attainment and illiteracy rates can be considered socio-economic vulnerability factors because of their direct relationship with economic capacity and employment opportunities [34,35]. Landlords make improvements to their buildings and have insurance coverage, unlike tenants [41]. In terms of the exposed elements criterion, the land use and population density sub-criteria have a slightly higher contribution than building density. Urban areas were considered to be the most relevant sub-criteria. In urban areas with high population densities, the rescue process can be challenging. There is also a correlation between high population density and the presence of low-income families [46].