# Methodology for the Assessment of Multi-Hazard Risk in Urban Homogeneous Zones
## 3 Results
### Multi-Hazard Risk Assessment of Homogenous Zones  
Three natural-hazards--seismic, flood and extreme waves--are combined and evaluated together to assess the multi-hazard risk, and the analysis is made on the level of homogenous zones. The two combined risk analysis are made: combination of two risks for seismic and flood hazard; and combination of three risks for seismic, flood and extreme waves hazard. Each analysis is made on three levels. The first level of analysis is based on hazard and  
Figure 12: Results of the PROMETHEE method for 14 homogeneous zones (better rank represents higher risk). Figure 13: Seismic risk assessment for homogenous zones (green represents low risk, red represents high risk). vulnerability data aggregated for each homogenous zone. A second and third level of analysis are using additional criteria for each homogenous zone (Table 3). Therefore, six multicriteria analyses are made on three different levels for each of the two scenarios. These multi-criteria analyses are classifying homogenous zones in accordance with multi-hazard risk. The first analysis is the combined seismic-flood risk (Scenario S-F) on three different levels. Each level represents different criteria sets. Criteria are grouped in two major groups: main criteria, which are related to hazard and vulnerability and additional criteria, which are related to some important spatial data. Each criteria group has its own weight. In this case, an equal weight is given to each group--50%. An example of distribution of the criteria weights within the group are presented in Table 4. Criteria weights in this particular application are estimated comparing the estimated Expected Annual Damage values for each observed natural hazard. The Expected Annual Damage concept is based on the combination of occurrence probability and corresponding damage caused by each natural hazard [48], and it has proved to be an effective method since it enables a practical comparison of significantly different natural phenomena. \begin{table}
\begin{tabular}{c l l} \hline \hline
**Level** &
\begin{tabular}{c} **Combined Seismic-Flood Risk:** \\ **Scenario S-F** \\ \end{tabular} & **Combined Seismic-Flood-Extreme Waves Risk: Scenario S-F-EW** \\ \hline Level 1 criteria & Seismic hazard (1.1) & Seismic hazard (1.1) \\  & Seismic vulnerability (1.2) & Seismic vulnerability (1.2) \\  & Flood hazard (1.3) & Flood hazard (1.3) \\  & Flood vulnerability (1.4) & Flood vulnerability (1.4) \\  & & Extreme waves hazard (1.5) \\  & & Extreme waves vulnerability (1.6) \\ \hline Level 2 criteria & Seismic hazard (1.1) & Seismic hazard (1.1) \\  & Seismic vulnerability (1.2) & Seismic vulnerability (1.2) \\  & Flood hazard (1.3) & Flood hazard (1.3) \\  & Flood vulnerability (1.4) & Flood vulnerability (1.4) \\  & Construction density (2.1) & Extreme waves hazard (1.5) \\  & Inhabitation density (2.2) & Extreme waves vulnerability (1.6) \\  & Importance factor (2.3) & Construction density (2.1) \\  & Historical buildings (2.4) & Inhabitation density (2.2) \\  & & Importance factor (2.3) \\  & & Historical buildings (2.4) \\ \hline Level 3 criteria & Seismic hazard (1.1) & Seismic hazard (1.1) \\  & Seismic vulnerability (1.2) & Seismic vulnerability (1.2) \\  & Flood hazard (1.3) & Flood hazard (1.3) \\  & Flood vulnerability (1.4) & Flood vulnerability (1.4) \\  & Construction density (2.1) & Extreme waves hazard (1.5) \\  & Inhabitation density (2.2) & Extreme waves vulnerability (1.6) \\  & Importance factor (2.3) & Construction density (2.2) \\  & Historical buildings (2.4) & Inhabitation density (2.2) \\  & Electrical infrastructure (3.1) & Importance factor (2.3) \\  & Water supply infrastructure (3.2) & Historical buildings (2.4) \\  & Road network (3.3) & Electrical infrastructure (3.1) \\  & Water supply infrastructure (3.2) \\  & Road network (3.3) & Road network (3.3) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Combined risks analysis and criteria for each level of analysis.