Analysis of factors affecting the resilience of sensitive and vital urban centers based on passive defense

Currently, more than half of the world's population lives in urban areas. Yesterday's cities have become metro police and mega-police, and this has led to the emergence of various challenges and urban issues. Therefore, in the present era, the main focus of cities as the most dynamic areas of housing is sometimes to achieve development and its dimensions and components in order to deal with and reduce urban challenges and harms. Urban resilience is the extent to which cities can withstand change before being reorganized into a new set of structures and processes. Special and sensitive urban centers are among the areas that are considered as vital arteries due to the complex structure of urban life and the dependence of urban society on them, and as a result, the issue of their vulnerability and resilience is essential because any failure leads to many problems for the urban society and reduces the quality of life and ultimately failure in development goals. In the meantime, one of the approaches considered in promoting the resilience of special, vital and sensitive centers and reducing their vulnerability is passive defense. District 11 of Tehran is one of the central areas of the city, which is considered as part of the CBD and the historical, economic, administrative and medical heart due to the existence and establishment of important political, military and economic centers in the country and has become one of the special, vital and sensitive centers which consequently, plays a key role in the life of urban society. Currently, one of the challenges of urban management in the district 11 of Tehran is the issue of resilience of special, vital and sensitive centers with emphasis on passive defense criteria. Accordingly, and considering the necessity of the subject, the present study seeks to analyze the factors affecting the resilience of special, vital and sensitive centers in the district 11 of Tehran based on passive defense criteria.

The present research is part of applied and descriptive-analytical researches in terms of purpose and method, respectively. The required information was collected through library and field methods using a questionnaire. The components of passive defense (six components) and resilience (four components) were identified according to the views of experts. Then, a questionnaire was designed, which was provided to seven experts to assess its validity and was approved. Cronbach's alpha was used for the reliability of the questionnaire, which was obtained above 0.8 for all items and was therefore acceptable. The statistical population of the present study includes experts and specialists in the field of geography and urban planning. For more effective analysis, considering the use of PLS structure equations software, the statistical sample size was estimated through Sample Power software, which is equal to 215 people. It should be noted that the working method of Sample Power software is based on latent and obvious variables and therefore the size of the statistical population has no effect on estimating the sample size. The sampling method is also simple random. SPSS software was exerted to estimate the descriptive statistics, and Smart-PLS software has been applied to analyze the collected data and discover the effect of each component of passive defense on the dependent variable of resilience.

According to the results, all 7 factors (passive defense components) and its effect on the resilience of special, vital and sensitive centers were significant and confirmed. Based on the analyzes, location and multifunctional factors with path coefficient (impact) of 0.826, dispersion, division and displacement with 0.708, fortifications and safe structures with 0.582, access with 0.513, camouflage and deception with 0.490, concealment and cover with 0.410, and news announcement with 0.175, respectively, have the most impact on the resilience of special, vital and sensitive centers of Tehran's 11th district. The important point that can be seen in the findings is the location and multifunctionality of land uses, which was ranked first and indicates the importance of this factor in the resilience of the centers and requires special attention. Also, it became clear that the outcome of resilience of special, vital and sensitive centers is economic resilience with a coefficient of 0.819, social with a coefficient of 0.767, physical-environmental with a coefficient of 0.607 and institutional-managerial with a coefficient of 0.594.

Looking at the current situation of district 11 of Tehran and reviewing data, statistics, figures and field observations, it can be seen that this region is facing challenges in resilience of important and sensitive centers, which the presence of worn-out textures intensifies it. Therefore, as the analysis of the findings showed, the location and multifunctional factor with an impact factor of 0.826 has the greatest impact on the resilience of sensitive, important and vital centers in the region. And it is necessary that in the first place, the relevant authorities take steps to review and reform the existing management structures in order to achieve this factor, which indicates the need to establish integrated management of institutions, both at the regional and national level.