Recent seismic events show that urban areas are increasingly vulnerable to seismic damage,which leads to unprecedented levels of risk.Cities are complex systems and as such their analysis requires a good understanding of the interactions between space and the socioeconomic variables characteristic of the inhabitants of urban space.There is a clear need to develop and test detailed models that describe the behavior of these interactions under seismic impact.This article develops an overall vulnerability index to seismic hazard based on a spatial approach applied to Bucharest,Romania,the most earthquake-prone capital in the European Union.The methodology relies on:(1) spatial post-processed socioeconomic data from the2011 Romanian census through multicriteria analysis;and(2) analytical methods(the Improved Displacement Coefficient Method and custom-defined vulnerability functions)for estimating damage patterns,incorporated in a GIS environment.We computed vulnerability indices for the128 census tracts of the city.Model sensitivity assessment tested the robustness of spatially identified patterns of building vulnerability in the face of uncertainty in model inputs.The results show that useful seismic vulnerability indices can be obtained through interdisciplinaryapproaches that enhance less detailed datasets,which leads lead to better targeted mitigation efforts. Recent seismic events show that urban areas are increasingly vulnerable to seismic damage, which leads to unprecedented levels of risk. Cities are complex systems and as such their analysis requires a good understanding of the interactions between space and the socioeconomic variables characteristic of the inhabitants of urban space.There is a clear need to develop and test detailed models that describe the behavior of these interactions under seismic impact. This article develops an overall vulnerability index to seismic hazard based on a spatial approach applied to Bucharest, Romania, the most earthquake-prone capital in the European Union. The methodology relies on: (1) spatial post-processed socioeconomic data from the 2011 Romanian census through multicriteria analysis; and (2) analytical methods (the Improved Displacement Coefficient Method and custom-defined vulnerability functions) for estimating damage patterns, incorporated in a GIS environment.We computed vulnerability indices for the128 census tracts of the city.Model sensitivity assessment tested the robustness of spatially identified patterns of building vulnerability in the face of uncertainty in model inputs.The results show that useful seismic vulnerability indices can be obtained through interdisciplinaryapproaches that enhance less detailed datasets, which leads lead to better targeted mitigation efforts.