Spatial analysis of the physical resilience of old urban neighborhoods against earthquakes: a case study of the old texture of Tehran

During their growth, cities reach a point where they need to renew their structures. At this stage of urban growth, part of the urban environment with less livability as well as non-compliance with the current needs of citizens gets to be known as urban old neighborhoods. These neighborhoods are always exposed to all kinds of damage due to physical decay, inappropriate access, poor service facilities and inefficient infrastructure. One of the most serious and destructive types of damage is the one caused by earthquakes, which not only affects the physical aspect of urban textures but also leads to social and economic crises. The aim of this research is to measure the physical-environmental resilience of old neighborhoods and analyze the factors affecting it. The sources of the data in this regard are the census of the Iranian Statistics Center, the Detailed Plan, the Organization of Urban Renovation, and the district municipalities in 2022. With the consensus of experts' opinions, 10 out of 23 indicators were selected to achieve the aims of the research. As the standard indicators were combined, an urban area with a cluster of 123 old neighborhoods was selected as the statistical population of the research. The entropy method was used to assess how important each indicator of physical-environmental resilience was. The rates of physical resilience and environmental resilience were determined through overlaying the corresponding layers by the GIS software, and the final resilience was calculated with the geometric mean values. The geographically weighted regression (GWR) method was also used to analyze the factors affecting the final resilience. The findings indicate that old urban neighborhoods have much lower physical resilience than the other urban textures, but the rate of resilience is different among old urban neighborhoods. Moreover, in each neighborhood, the physical resilience of housing and the environmental resilience are different, which is caused by the highly different conditions of the neighborhoods in terms of resilience indicators. Also, the finesse of residential units, distance from the fire station, and access to green and open public spaces emerged to be the factors that play major roles in physical-environmental resilience. Being aware of what causes the vulnerability of old textures can be useful to solve their problems, improve their resilience against earthquakes, and provide information to local stakeholders.