# Risk and Resilience Assessment of Lisbon's School Buildings Based on Seismic Scenarios
## 2 State of the Art on Seismic Risk Assessment and Mitigation for School Buildings
### Empirical Approaches for Risk and Vulnerability Assessment  
Risk and vulnerability assessments are most commonly derived: (i) from expert opinions (expert/judgmental-based); (ii) from statistical processing of post-earthquake reconnaissance data (empirical/observational); or (iii) through analytical/numerical simulations.  
Risk quantification of large school portfolios through the development of empirical risk mitigation prioritization approaches led to the development of rapid surveying forms and rapid assessment procedures that were proposed by different authorities and organizations, such as the World Health Organization (WHO) and the United Nations (UN), with special focus on developing countries. For instance, [PERSON] et al. [40] collected and assessed the physical condition of 1381 school building units in Nepal by mobilizing the school teachers. School vulnerability, calculated on the basis of empirically weighing different factors (e.g., structural material, number of stories, and shape of the roof), was used to estimate the possible damage, casualties, and injuries caused by earthquakes of different seismic intensities. Different statistical methods were used for fragility derivation of the Nepalese school building portfolio, for instance by [PERSON] et al. [41], based on the World Bank's data collected after the 2015 Gorkha sequence.  
Other empirical risk assessment frameworks were also developed in countries with high risk of seismic activity, as is the case of Peru, where a project was funded by the government of Japan and the Global Facility for Disaster Reduction and Recovery [34], Turkey, with the Istanbul Seismic Risk Mitigation and Emergency Preparedness (ISMEP) Project, initiated in 2006, as well as Indonesia, where the Indonesia School Programme to Increase Resilience (INSPIRE) tried to develop an advanced, harmonized, and science-based risk assessment framework for school infrastructure in Indonesia, subjected to cascading earthquake-tsunami hazards [6]. The INSPIRE seismic risk prioritization index aims at providing a simple method to derive a prioritization scheme, minimizing the subjectivity involved in the calculation. This work combines the INSPIRE metric, which allows for empirically assessing the seismic risk and defines prioritization strategies for risk mitigation, and the Papathoma Tsunami Vulnerability Assessment (PTVA) index [42]. This is a step forward in defining a multi-hazard risk assessment methodology. Such a multi-level framework is implemented for 85 reinforced concrete (RC) school buildings in Banda Aceh, Indonesia, the most affected city by the 2004 Indian Ocean earthquake-tsunami event.  
However, conducting empirical studies may be unfeasible in data-scarce regions [37], such as Portugal, where the return periods of seismic action are significantly large. For this reason, the development of numerical studies, such as the ones referred to in the following paragraphs, based on the characteristics of local buildings, are deemed necessary.