# Seismic Risk Assessment of Chania, Greece, Using an Integrated Computational Approach
## 4 Seismic Risk Analysis Results  
### Results Based on the Kythira Earthquake Local Seismic Model  
In this section, characteristic results of the application of QuakelST for the seismirisk assessment of Chania are provided, based on the Kythira earthquake local seismic modelreported by [PERSON] [51].The seismological data were taken from the relevant study of [PERSON] et al. [52]. The maps with average damage rates presented in the sequence are the outcome of the fragility analysisusing the available models of QuakelST taking into account the spatial distribution and vulnerability (due to construction type, material, and age) of existing buildings as well as the local site conditions that affect soil dynamic response. In particular, the seismic vulnerability and damage assessment methodologies proposed by [PERSON] and [PERSON] [38] in the framework of the RISK-UE project have been adopted for the purposes of the present study. In general, such approaches are suitable for buildings for the countries at the south of Europe, since field surveys from past earthquakes (e.g., as the recent ones in Greece and Italy) have demonstrated that the building typologies, construction materials, practices, norms, etc., as well as the scales of damage are quite similar. More specifically, the software contains the proper tools to assess all potential impacts in the area of interest when exposed to a certain seismic scenario. Hence, the user can define all parameters involved and derive the structural damage intensity at a localized level, i.e., for each building block. In this manner, average damage rates can be estimated taking into account specific characteristics of all buildings in each building block (age, material, typology, geometry, density, etc. ), as shown in the following plots. As earlier mentioned, the vulnerability assessment is based on the study of [PERSON] [38], who provided a well-established probabilistic methodology that leads to reliable estimates of mean average damage rates of buildings, \(\mu_{D}\) (with values \(0<\mu_{D}<5\)) taking into account macroseismic intensity as well as suitable vulnerability and ductility indices. In other words, the vulnerability in terms of \(\mu_{D}\) is calculated for each building of every block that presents any type of damage. In this manner, the mean damage rate is derived taking into account the status of the whole block. In addition, the user can elaborate more on the results, by extracting the likelihood of the occurrence of damage belonging to the five possible levels according to the classification in Table 1, as it will be presented in the sequence. For instance, most building blocks near the old Venetian harbor are densely built, while most buildings are old, stone-built, and more vulnerable. Consequently, these parts of the city exhibit much higher average damage rates compared to the outskirts of Chania, where the building blocks are less dense and mainly contain newer, earthquake-resistant, reinforced concrete buildings. As is clearly illustrated in Figure 4, the northwestern part of the city of Chania exhibits the highest seismic risk. This was expected due to the age of the buildings (the majority built before 1960), their construction material (mainly stone-built), and also due to the softer soil layers that exist in this part of the city. In the central part of the urban complex, despite the expected diversity of structural conditions, a rather medium seismic risk can be observed. The differences that are observed are not so pronounced, taking also into account the quite large dimensions of this area. Lastly, the city suburbs at the perimeter of the urban complex present the lowest seismic risk. QuakeIST has a built-in library with the classification of earthquake-related impact levels (damage, social, economic, etc.) [24].