Assessment of Urban Resilience using an Objective and Subjective Approach during Hurricane Harvey

The sustainable form of cities has been considered since the formation of first cities, but with the increasing exposure of cities to uncertainties such as natural disasters, climate change, drought crises, and energy crises, this stability is disrupted. The resilient and stable form of cities has achieved a special importance and this concept has been considered by many researchers. Urban resilience is a multidimensional concept that is measured using both objective and subjective approaches. This study calculates Texas urban resilience using both objective and subjective approaches during Hurricane Harvey 2017 to provide an overview of the actual situation and public perception, respectively, and to examine the relationship between the two approaches. In the objective approach of the research, by integrating social, economic, infrastructural, organizational indicators with a certain weight, it was extracted by DANP method and cities were ranked by TOPSIS method. The DANP method used the opinions of experts, which had a high reliability. In the subjective approach, the Twitter data were used and the ratio index was used. The results of the objective approach indicated that the most resilient cities were Harris, Austin, Fort Bend, Galveston, Brazoria, Chambers, Rockwall and the least resilient cities were Moore, Presidio, Dimmit, Starr, Jasper, Camron, and Kennedy. A total of 24 cities were selected to compare resilience changes in the two approaches, as these cities had more than 50 Twitter messages and were facing direct threats from Hurricane Harvey. The results showed that the correlation coefficient between the two approaches in these cities was 0.708. There was a strong positive relationship between the two approaches, which means that cities that in terms of resilience were at a higher level, shared more Twitter messages when faced with a crisis. The knowledge gained from this study can provide valuable insights into strategies for using social media data to increase resilience to natural disasters.