Environmental Revitalization of Distressed Urban Fabric Through Landscape Metrics Approach, the Case of District 9th Tehran City

Currently, many decayed urban fabric inside the cities suffer from physical problems, lack of sufficient green space and proper accessibility, and weak infrastructure. In order to overcome these problems, some researchers have proposed the creation and strengthening of urban infrastructures through the connection of open and green spaces in urban environments. The aim of this research is to improve the ecological network structure of the green space network of the 9th district of Tehran through landscape metrics, to achieve a better quality of life and improve the environmental conditions in these areas. Based on this, at first, using satellite images and land use map of Tehran city, the required geographical data of the network map within the decayed fabric of the 9th district of Tehran was prepared. And then two levels were chosen to restore the green patches: the macro level (Teheran District 9) where the most important green spaces and their changes during the years 2002, 2017 with the help of landscape metrics (CAP, NP, MNN, MPS, LPI, AWMSI, MSI, PD) was calculated in FRAGSTATS 4.2.1 software; and the micro level was considered: distressed urban fabric of neighborhoods such as Dastgheyb, Imamzade Abdullah, Shamshiri, Sar Asiyab Mehrabad. By determining the most important green patches and identifying the optimal corridors based on the resistance of the landscape at the macro level and with the help of graph theory and the minimum cost model, these spaces were connected at the macro level and then at the micro level, creating an ecological network within the urban fabric. The findings of the research show that the green patches in terms of size, number, continuity, composition and spatial distribution in Region 9 have suffered severe destruction. And the fragmentation of green spaces and the distance between them has increased in 2017. It is recommended to protect the privacy of the Kan River, transfer the industries from the area and release their spaces to increase the open spaces and vegetation and the network of green spaces in the open spaces of district 9.