The Analysis of Structural Landscape Changes in Tabriz City Using Landscape Ecology Principles with an Emphasis on the Connectivity Concept

Urban societies are complex landscapes that face unbalanced and exogenous growth and are rapidly changing as a result of population growth and urbanization. That is to say, non-urban, large swaths of land are consumed by cities and urban settlements, and over time they are fragmented into smaller pieces. Therefore, the present study was designed to detect and evaluate changes in the landscape structure of Tabriz metropolitan area and to evaluate the performance of landscape metrics in analyzing changes. To this end, first the land use maps for 1984, 2000 and 2018 were prepared using Landsat satellite imagery. Then, in order to analyze the changes, a combination of Landscape metrics including NP, CA, PLAND, LPI, ED, MPS, LSI, and COHESION was computed at two levels of land class and landscape using Fragstats4.2 software. The results showed that the lands used for urban settlement during this period have had the most changes and growth, in contrast to agricultural farms, gardens and green-space which have had a downward trend and have been converted to other uses. Also, the number and density of patches have increased over time, leading to the fragmentation of the landscape. On the other hand, the average size of patches belonging to constructed lands and agricultural and horticultural lands respectively increased and decreased, and caused more distortion and complexity of Tabriz city landscape through an increase in the landscape shape index. In general, the analysis of land use maps and landscape metrics clearly reveals the effects of human activities and urbanization on the surrounding environment, and the results indicate that the landscape of Tabriz has got more granular, more complex and geometrically more irregular. Then, with this decreasing connectivity, it has become more fragmented.