بررسی روند کاهش فضاهای باز شهری در فرآیند توسعۀ شهری با تأکید بر مدیریت بحران، نمونۀ موردی کلانشهر تهران

Urbanism can be regarded as one of the most influential as well as comprehensive areas encompassed which encompasses many other subcategories. In fact, due to the its key role in the process of structural development of cities and formation of the qualitative as well as quantitative aspects of development, at a macro level, Urbanism can play a critical role in the procedure of equipping urban residential areas against the consequences of catastrophes, which may occur pursuant to both environmental or human factors. Effective review mechanisms in shaping the process of open spaces and reducing the modeling process to identify and correct problems in the form of destructive mechanisms dynamic systems theory can be investigated. Based on the dynamic systems theory, this article the fundamental dynamics of the process of structural development of Tehran. In addition, it analyzed the influential elements in the decreasing rate of the urban open space, adopting an approach to use them during the crises. Actually, the main objective was examine the trend of decreasing open spaces which have the potential to be utilized during the crises, within the framework of dynamic systems. regarding that, the related mechanisms and their structures were examined and based on the analyses, new policies were recommended in order to improve the destructive mechanisms. First and foremost, the structural framework as well as the internal and external variables of the issue is determined. In the next step, the behavior of the key variable in a specific period of time is scrutinized. Using the results of the analysis of the key factor and the effects of other elements, then some dynamic hypotheses are made. In a further section, a conceptual model and the related diagrams are presented. And finally, the parameters are defined and the dynamic hypotheses are examined by means of the Vensim PLE software, which resulted in a suggested model of the issue for a period of 20 years that may be applicable in the future. This model is then tested for various conditions. The purpose of the present study is to examine the trend of decreasing open spaces in the process of urban development, within the context of Tehran metropolis. Providing a model for the improvement of destructive mechanisms, the article offers an image of the future situation. The study is based on analytical- descriptive methods of discussion and the required information is collected through library research and a field study. The results of the study reveals that if the destructive mechanisms are improved, and if the policies related to the control of key variables of the issue are implemented, we may be able to control the downward trend of the open spaces in Tehran for a mid- to long-term period, aiming to use them during the crises.