Evaluation and analysis of the trend of land landscape changes in urban green spaces of Tehran

The purpose of this study is to identify the structure of the land and identify the structural problems of natural lands in each urban area of ​​Tehran. Understanding the structure of the landscape, which is the result of functions and processes such as climate, geology, natural and artificial disturbances, is possible by describing the composition and distribution of spots and corridors. In this research, using land cover maps obtained from Landsat satellite images in 2003 and 2013, the status of structural elements in Tehran has been investigated. For this purpose, the metrics of CAP, PD, MPS and MNND, which are important in interpreting the composition and spatial distribution of structural elements in the landscape, have been calculated with Fragstats software in the mentioned two time periods. After calculating the metrics, important indicators such as presence, stability and continuity were evaluated. The results showed that the ratio of green spots in the total area of ​​Tehran has increased in the period under review, which is considered a positive change. But the change in other metrics has been a negative one. Due to the increase in the number of green and open spots along with the size of the spots, it seems that the trend of change has been associated with the fragmentation of natural areas, reduced relative relationship and continuity between spots. Although the decrease in the distance between the spots seems to have had a positive trend and has decreased in most areas, but comparing with the trend of changes in other metrics such as the average size and number of spots (decrease in MPS and increase in PD), it can be concluded that this decrease in distance It happened because of the crushing of the stains.