Evaluation of the Vulnerability of Urban Morphology to Air Attacks Using Passive Defense Approach Case Study: 6th District of Tehran

Nowadays, with the advent of long distance military weapons, the role of cities has become more important in provide safety in wars. Military threats have continued due to insecurity in the Middle East and the presence of valuable potentials in Iran. Safe urban design, by paying attention to the physical vulnerability of the city against threats, can improve the conditions of cities. It tries to plan new urban development properly or to solve existing problems by identifying appropriate urban morphology from the perspective of passive defense. Obviously, some concepts such as city structure, urban texture, urban form, density, and urban networks can be effective in reducing the vulnerability of the city to military strikes. In this context, it seems that such concepts should be reorganized and redesigned. Observing passive defense considerations in designing and organizing urban facilities can significantly reduce their vulnerability. Moreover, recognizing the characteristics of suitable urban morphology from the perspective of passive defense in new urban development can be a solution for urban security. The purpose of this study is to evaluate the vulnerability of various urban sprawl against air strikes from the point of view of passive defense considerations. As a case study, the 6th district of Tehran has been selected because of valuable land uses, such as ministries, governmental agencies and private organizations. The method of measuring the vulnerability of various urban sprawl against air strikes in this research is descriptive-analytic. This practical research is carried out by collecting theoretical literature review using documentary methods. The survey method with observation, interview and questionnaire is used to achieve this goal. For this purpose, evaluation criteria are extracted by studying theoretical literature of passive defense considerations and urban morphology. These criteria are determined by conducting interviews with experts and were cared for in the Delphi method. The statistical society of this study are urban planners and architects who are proficient in passive defense considerations at relevant universities and organizations. Twenty of them were randomly selected to complete the questionnaire. Then, using the Inversion Hierarchical Weight Process (IHWP), the importance and weight of the criteria and sub-criteria were determined. The GIS software program, by disassembling layers for each criterion, provides the final vulnerability map for the 6th district of Tehran. Due to the objective and scope of the study, it only examines the vulnerability through the map. However, Argentina Square, Kargar Street and the Shahid Ghomnam Highway have high vulnerability in the area due to their high construction density and old age. Generally speaking, it can be concluded that smaller blocks with low shaped compaction, along with large land lots and low occupancy levels of the masses, can be regarded as an appropriate city morph from the perspective of passive defense. Regarding the buildings, low density and newly constructed ones, proper quality and low complexity form are considered appropriate. Moreover, wide streets, confinement, and low-level integration are appropriate from this perspective.