Development of a seismic social vulnerability model for northern Algeria

A common definition of seismic risk entails the quantification of three main elements: hazard, exposure of properties and societies, and corresponding vulnerability. When properly characterised, the vulnerability of a community or an asset is the easiest component to act upon, through governmental agencies and decentralised frameworks, when facing natural hazards. Algeria is a country with a relatively short history of seismic risk mitigation even though, in the past, the population suffered from many devastating earthquakes leading to large human and economic losses. Furthermore, until now, the actions taken to reduce such devastating effects have been of reduced impact. With this in mind, this paper investigates the social vulnerability and resilience level to natural hazards, with a specific focus on seismic risk, in the province of Blida, an important cultural and economic region in Northern Algeria. The evaluation is carried out through a hybrid methodology that puts together results from the well-known social vulnerability index or SoVI®, obtained from population data and national statistics, integrated with the Resilience Performance Scorecard (RPS) method, which qualitatively assesses the resilience of a population with reference to qualitative information gathered through public interest and participation. With such a methodology, this study aims to evaluate the societal factor and the impact on the population at risk through vulnerability mapping. The results allow identifying the areas and the social vulnerability dimensions requiring immediate addressing by regulatory and institutional frameworks that can increase preparedness levels, resource allocation, contingency planning, and efforts in raising public awareness. Following the use of census data and the participatory scheme, as well as a hybrid approach combining the two, it is seen that the province of Blida is characterised by medium levels of vulnerability. Following a simplified comparison, the SoVI approach results tend to underestimate the RPS ones. Such information will be useful to aid decision-makers and the exposed society itself to endure the effects of disastrous events.