## 4 Discussion and Conclusions
### Limitations and Suggestions  
The results of this study are strictly linked to the application of census tracts as a measure and geographic units. Although the use of this cartographic base is essential for research developed at the local level, many limitations need to be clarified. The census tracts show significant differences in terms of extension. Some of them limit inhabited centers, while others only cover portions of roads or special areas made up of particular geomorphological entities, such as lakes, maritime islands, marshes or ponds, lagoons, fishing valleys, lakes, and uninhabited mountains [67]. As a consequence, relative or comparative analyses become complex within the same territory as the low frequency of census tracts falling in the same class would not correspond to low values of extension and therefore low exposure. In order to overcome this issue and to work on the same cartographically extended units, it would be useful to include grid cells of the same resolution [68; 69; 70]. Another limitation is the lack of open census data at the sub-municipality level. As shown in this research, only a few variables, that increment social vulnerability, were available from national datasets. Therefore, it is highly recommended that researchers provide and collect more socio-economic data for detailed vulnerability analyses, allowing the application of rigorous statistics, which form the basis of quantitative investigation. Another improvement, in terms of socio-economic features, could be the inclusion of land use data that can highlight the main characteristics of the territory exposed to hazards and that could help in the interpretation of the different types of vulnerability among the census tracts, as carried out in other studies conducted at the municipality level [71]. Concerning the development of this research, more effort should be put into hazard calculation. Results connected to flood return periods that range between 100 and 500 years could provide information about extreme events that have rarely occurred during human life. Indeed, one of the greatest challenges in risk studies is the understanding of the methods that are needed to combine periods related to natural and social processes. This is a key point in developing a climate change perspective that highlights the increase in the frequency and intensity of extreme events and will require high-resolution hazard assessments characterized by shorter return periods than those considered in the European Directive. As regards the landslide hazard assessment, a detailed susceptibility analysis could also be applied in risk analysis and integrated with social vulnerability [72; 73]. In this context, physical vulnerability, related to the structural features of buildings and infrastructures, such as construction age, material, and the state maintenance of buildings, could be introduced as a development tool for landslide management strategies [74; 75; 76]. The last suggestion concerns the multi-hazard concept. In this study, we consider the coexistence of different hazards in the same territory. However, a challenging perspective would include the relationship between different hazards that provide more detailed information for multi-risk emergency planning. In this respect, improvements in quantitative correlations between multi-hazard scenarios could be achieved through stochastic, empirical, and mechanistic approaches [77]. This could help the scientific community and local authorities to increase their knowledge about multi-hazard contexts and implement adequate management strategies. Conceptualization, IL. ; investigation, IL. ; data curation, R.C. ; writing--original draft preparation, IL. ; writing--review and editing, R.C. and A.R. ; supervision, D.C. All authors have read and agreed to the published version of the manuscript.