Document Type : Research article
Authors
1
Ph.D. Candidate, Department of Forestry and Forest Economics, Faculty of Natural Resources, University of Tehran, Karaj, Iran
2
Prof., Department of Forestry and Forest Economics, Faculty of Natural Resources, University of Tehran, Karaj, Iran
3
Prof., Department of Environmental Science, Faculty of Natural Resources, University of Tehran, Karaj, Iran
4
M.Sc. Student, Department of Arid and Mountainous Regions Reclamation, Faculty of Natural Resources, University of Tehran, Karaj, Iran
Abstract
Background and Objectives: Urban forestry involves the management and planning of urban tree-covered spaces and forests within city boundaries, playing a crucial role in improving quality of life and urban livability. The importance of urban green spaces, especially in densely populated and compact areas, lies in their ability to reduce air pollution, regulate temperature, mitigate urban heat island effects, and enhance citizens’ mental health. Given the rapid pace of urbanization and the degradation of green spaces, evaluating the distribution and layout of urban green spaces, particularly in older and central areas like districts 10, 11, and 12 of Tehran city, Iran is essential. This study aimed to identify urban tree canopy layout patterns, determine green space per capita, and propose strategies to improve the current conditions in these districts.
Methodology: Tree canopy patch maps were prepared for the study areas using high-resolution Google Earth images. ArcGIS software and landscape metrics were utilized to analyze and model the spatial patterns of green space patches. Three types of green space layout patterns were defined: single-tree (isolated trees in residential areas), linear (trees along streets and sidewalks), and clumped (grouped trees in parks and public spaces). Population data of districts and sub-districts were extracted from Tehran Municipality records, and a green space per capita map was developed accordingly. Numerical analyses were conducted in Fragstats software to calculate metrics such as class area (CA), number of patches (NP), landscape shape index (LSI), and mean nearest neighbor distance (ENN_MN). The accuracy of the maps was validated through field observations, achieving an overall accuracy of 98.5% and a kappa index of 96.12%.
Results: The results revealed that linear layouts occupied the largest area in all three districts, with the highest area recorded in district 11 (103.48 hectares). Conversely, clumped layouts covered smaller areas, primarily in parks and public spaces, and were least prominent in district 10. Single-tree layouts, despite having a higher number of patches, contributed a smaller total area and were mainly observed in high-density residential neighborhoods. In terms of green space per capita, district 12 had the highest value (7.53 m²), while district 10 had the lowest (2.16 m²). This disparity highlighted significant inequities in access to green spaces across districts and sub-districts. Landscape metrics analysis demonstrated that LSI and ENN_MN are effective tools for assessing the dispersion and complexity of green space patches. In densely populated areas, patches tended to be smaller and more scattered.
Conclusion: The study concluded that linear layouts, due to their feasibility for implementation along streets and public pathways, are the most suitable option for high-density areas like districts 10, 11, and 12. Linear layouts can improve air quality, enhance visual aesthetics, and provide shade in urban environments. Meanwhile, clumped layouts, concentrated in parks and gardens, offer greater ecological benefits and are better suited for creating social spaces. For districts with a shortage of green spaces, such as district 10, developing small local parks and utilizing vacant lands for tree planting are recommended. Enhancing access to green spaces in these areas can reduce environmental inequalities and improve residents’ quality of life. This research provides a practical framework for urban planning and offers actionable strategies for achieving balanced development of urban green spaces.
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