Spatial analysis of urban resilience against earthquakes Case study: Region 1 of Tehran

Extended Abstract
Introduction
Due to the increasing growth of urbanization and the great damage caused by natural and human hazards to the environment and the body of urban settlements, the concept of resilience to reduce the effects of hazards has become an important area in crisis management. Urban resilience refers to the ability of an urban system to maintain or quickly return to optimal performance in the face of turmoil and adaptability to change. Today, resilience is not limited to academic topics; By including it in urban strategic documents around the world, understanding of resilience, identifying its dimensions and characteristics, and its relationship to different types of hazards have been examined.
Due to the location of Tehran in the high seismic hazard zone, extensive construction in the area of ​​faults and areas prone to geological instability, a wide range of vulnerable and worn tissues and weak operational capacity for disaster management, resilience indicators in Earthquake in area one of Tehran has been analyzed spatially.
 
Methodology
This research is applied in terms of purpose and in terms of descriptive-analytical method and is based on library and field methods. In the objective field of urban resilience, data from the 2016 census were used. A researcher-made questionnaire was used to collect the data required for research in the field of mind. This questionnaire contains 109 questions in various social, economic, institutional and infrastructural dimensions. The questions are mostly closed and designed in a 5-point Likert scale.
The statistical population of the study includes all households living in area one of Tehran, whose number in 2016 was 140,168 households. The sample size using the Cochran's formula is estimated to be 383 households. The type of sampling is spatial sampling. Data were analyzed using t-test in SPSS software and spatial analysis techniques in Arc GIS software.
 
Results and discussion
The results of analysis in the social dimension of urban resilience showed that the highest scores were related to the indicators of tendency to stay longer in the neighborhood, the amount of attention to housing quality and satisfaction with living, and the lowest scores were related to the indicators of earthquake probability, respectively. In the city of Tehran, local consensus and participation and the degree of neighborhood communication are close. The average score of the respondents in the social dimension in the Likert scale of 5 scales is equal to 3.13. The value of T-statistic for the social dimension of urban resilience is -5.598. Therefore, according to the results of T-test, it can be stated with 99% confidence that region one of Tehran based on urban resilience indicators in a social dimension has a good situation. In the institutional dimension of urban resilience, indicators of residents' satisfaction with firefighting performance, trust in laws to maintain order and residents' satisfaction with emergency performance with the highest score and indicators of efficiency and readiness of council and municipality, the amount of residents' demands to officials And the rate of application of opinions and participation of residents have the lowest score. The average scores of the respondents in the social dimension in the 5-point Likert scale are equal to 2.55 and the value of the T statistic for the institutional dimension of urban resilience is equal to 16.31. Therefore, it can be stated with 99% confidence that region one of Tehran city is in an unfavorable situation based on urban resilience indicators in the institutional dimension. In terms of resilience infrastructure, indicators of satisfaction with the quality of mobile phone service, satisfaction with the quality of telecommunication services and satisfaction with the quality of electricity and electrical installations, respectively, have the highest score and indicators of access to the route map and evacuation, access to Temporary accommodation and access to aid agencies have the lowest scores. The average score of the respondents in the infrastructure dimension in the Likert scale of 5 scales is equal to 3.07 and the value of T statistic for the infrastructure dimension of urban resilience is equal to -3.137. Therefore, it can be stated with 99% confidence that region one of Tehran city is relatively suitable in terms of infrastructure in terms of urban resilience.The results of the research in the economic dimension showed that the highest score is related to the indicators of earthquake vulnerable property and the level of neighborhood security and the lowest score is related to the indicators of residents' insurance coverage against earthquake and hope for institutional support, respectively. Mali is on the ground of an earthquake. The average score of the respondents in the economic dimension in the 5-point Likert scale is 1.48 and the value of the T-statistic for the economic dimension of urban resilience is equal to 29.67. Therefore, it can be stated with 99% confidence that region one of Tehran city is in an unfavorable situation based on urban resilience indicators in the economic dimension.
 
Conclusions
The results of the four dimensions of resilience show that neighborhoods have different resilience to each other. Also, each of the resilience indicators differs according to different economic, social, institutional and infrastructural conditions and characteristics. The average score in the social dimension is 2.88, which indicates that the neighborhoods of the region are resilient in the social dimension. The average score of the institutional dimension is 3.45, which indicates the dissatisfaction of the residents of the region with the performance of government and local institutions. In the economic dimension, the most important components are the vulnerability of job supply sources, job security, and ownership. The average score on the economic dimension is 3.52, which is a sign of economic vulnerability and is relatively unfavorable in terms of resilience. The average score of the infrastructure dimension is 2.92, which is a sign that the region is becoming more resilient. The quality of buildings in Zone One is in poor condition due to the age of these neighborhoods. Neighborhoods such as Chizar, Darkeh, Darband and Qeytariyeh have more unfavorable conditions than other neighborhoods due to the existence of worn and old buildings. Also, high-rise construction at the neighborhood level causes population density and eliminates open space, which also increases vulnerability and reduces resilience. Spatial analysis combining objective and subjective dimensions was used to identify hot spots in area one. The results showed that the neighborhoods of Darband, Zafaranieh, Mahmoudieh, Araj, Chizar, Rostamabad, Azgol, Golha town, Shahid Mahallati town, Imamzadeh Ghasem and Naft town are in inappropriate conditions of mental and objective dimensions of resilience.