Urban-rural Gradient Landscape Analysis of Tehran Metropolitan in 2008 and 2018

Urban expansion causes fundamental changes in the ecological landscape structure and function and a gradual change in the spatial structure and pattern of the landscape. Due to the importance of understanding the components of urban environment and how to understand the interactions between these components, the aim of this study is the urban-rural gradient analysis of Tehran using landscape metrics to quantify the landscape pattern.

Research data were collected in 2019 and the combination of gradient analysis and landscape metrics has been used to quantify the pattern of Tehran landscape. Land use maps of Tehran were classified using Landsat 7 and 8 satellite images related to 2008 and 2018 in ENVI 5.3 in categories of built-in land, open land, vegetation land and water. For the gradients analysis, a number of 4km×4km transects were designed in the four main directions, and passing through region 12 of Tehran. To calculate the mestrics of Number of Patches, Patch Density, Edge Density, Percentage of Landscape, Mean Patch Size and Mean Shape Index on both landscape and class levels used the moving-window technique.

From 2008 to 2018, urban development has increased the Patch Density in the landscape. So in the central transect the continuity of the landscape has decreased and the fragmentation of the structural components has increased. At the level of the landscape, the Number of Patches and the Edge Density have increased dramatically. However, the Mean Patch Size and the Mean Shape Index have decreased. At the class level, the Mean Patch Size of open lands and built-in land has increased.

Along transects in addition to land use changes, Shape and Patch Density have also changed, and the process of these changes along transects is different. The percentage of built-in lands is the dominant matrix in transects near the commercial center of Tehran, and the area of vegetation lands and water has decreased from 2008 to 2018.