Effectiveness of social and governance strategies on improving urban resilience against earthquake

The study of the resilience of the cities against earthquake is one of the necessities for the reduction of losses and death toll of the earthquakes. Resilience has various definitions and there is not a unique comprehensive model for its quantitative assessment. Therefore, the aim of this paper is to provide a comprehensive quantitative indicator for resilience and to study the efficacy of social and governance strategies in improvement of urban resilience against earthquake. To achieve this aim, first effective dimensions and indices of resilience of urban areas were explored and extracted by reviewing available research studies and experts elicitation method. Then based on experts’ opinions and pairwise comparison the model was justified and the relative weights for dimensions and indices were obtained and a comprehensive overall resilience index was introduced. Using the proposed index, the efficacy of different social and governance strategies were compared considering three different earthquake scenarios of North-Tehran, Ray fault, and floating faults. The comparisons were based on three metrics i.e. absolute value of resilience increase, distance from the origin of the Pareto chart considering implementation duration time and costs, and the ratio of cost to resilience increase. In this regard, strategy S3 (90 percent increase of social resilience), strategy S1 (10 percent increase of social resilience) and strategy S3 were the optimal ones based on the first, second and third metrics, respectively. On the whole, the social strategies had better efficiency than the governance ones, but it seems in practice the social and governance strategy categories must be implemented in an integrated manner which could be considered as a future research proposal.