## 2 Materials and Methods
### Methodology
#### 2.2.5 Vulnerability  
Assessing the vulnerability of a study area is a crucial step in understanding its resilience to potential hazards, such as fire incidents. In this study, focus was given to three critical layers to assess fire vulnerability: population density, population age, and building materials [27]. Population density and age are essential factors in fire risk assessment because they influence the number of people potentially affected by a fire event. To evaluate the vulnerability related to population density, this study utilized detailed census data at the building-block level to determine the total number of people residing permanently within the study area's settlements. By dividing this population count by the total area of each building block, the population density was calculated in units of persons per square meter using Equation (3). \[Population\ density=\frac{Total\ population\ (per\ building\ block)}{Total\ area\ (per\ building\ block)} \tag{3}\]  
Once the population density layer was generated, a classification process was employed to divide the population density layer into five vulnerability classes. For this  
Figure 4: Input layers for parameterized FlamMap. purpose, the natural breaks classifier was applied. Specifically, the natural breaks classifier is a statistical method that seeks to identify natural groupings in data. This classifier helps determine appropriate class intervals based on the distribution of population density values [46]. The output of this process was further enhanced and updated (where needed) by utilizing the notes and data derived during the field visits. By enhancing population density estimation with field observations and recordings at a building-block level, the vulnerability assessment becomes more refined and representative of the specific characteristics of the study area. The approach accounts for variations in population distribution and the concentration of individuals in different parts of the study site, providing a more accurate and custom-made depiction of vulnerability related to population density. Population Age  
The study's analysis of census data to understand the vulnerability of different age groups to fire incidents is a crucial aspect of the fire risk assessment [44]. The census data provide age information for the following age groups: 0-9, 10-19, \(\ldots\), 60-69, 70-79, 80 plus. By grouping age data into five categories [Table 1] based on similarities in evacuation capacity during fire events, the analysis was simplified and supported the identification of the age groups that might have greater difficulty coping with fire incidents. By assigning weights to each age group based on their vulnerability and coping capacity in fire events, it is easier to quantify the relative importance of different age groups in the vulnerability assessment. To calculate the weighted population value for each age group in a building block, the total population of that age group was multiplied by its corresponding weight. To ensure accurate comparisons across different areas, the results were standardized by dividing the weighted population of each age group by the total population in the specific building block, as presented in Equation (4). \[Age\;Vulnerability=\frac{\sum_{k=0}^{k-5}(Age\;group(k)*Weighting\;factor(k))}{ Total\;population\;per\;building\;block} \tag{4}\]  
The consideration of building characteristics is crucial in assessing vulnerability and fire resistance. Building materials strongly influence a building's susceptibility to fire, how quickly it can ignite, and how fire might spread within the structure [45]. In this study, the census data provided valuable information about the materials that were used in the buildings within the study area. In particular, the materials that can be found in the study site are wood, metal, other materials, bricks/concrete, and stones. It is noteworthy that the 'other materials' of the census data were undefined.