Evaluation of ecological and morphological factors of urban heat island (Study sample: District 1 of region 1 and District 4 of region 6 of the metropolis of Tabriz)

Document Type : Origional Article

Authors

1 Master student of Urban Planning, Urmia university

2 Master student of urban management, Faculty of Urban Planning, Urmia University, Urmia, Iran

Abstract

Urban heat islands (UHIs) are a growing concern in metropolitan areas, leading to temperature differences between urban centers and surrounding areas due to various ecological, morphological, topographical, and demographic factors. Major Iranian cities have undergone rapid land-use transformations and expanding urbanization, facing the challenge of UHIs. This study investigates UHIs in Tabriz, focusing on District 1, Neighborhood 1 as the first area and District 6, Neighborhood 4 as the second area. The study employed Landsat 8 remote sensing images to analyze UHIs in Tabriz, Iran. The images were acquired for the summer season, representing the period of maximum UHI intensity. The Normalized Difference Vegetation Index (NDVI) was calculated to assess vegetation cover, while land surface temperature (LST) was derived using the single-channel algorithm. Morphological indicators were extracted from OpenStreetMap data. The study aims to extract, locate, and analyze UHIs in the study area using specific formulas and prepare relevant maps, focusing on ecological and morphological indicators. The minimum and maximum temperatures in District 1 were 15.88°C and 37.65°C, respectively, while in District 6, they were 24.11°C and 40.87°C. Analyzing the extracted maps based on the selected ecological indicators (vegetation cover, wind, solar radiation, and elevation) and morphological indicators (building height, building density, building façade, and building roofs) in both districts, we concluded that District 1 is cooler due to several factors: higher elevation, better reception of prevailing northeastern winds, more suitable street orientations, lower building heights (mostly one-story), and a higher prevalence of reflective roofs compared to District 6. Although District 6 has better vegetation cover and lower building density.

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Articles in Press, Accepted Manuscript
Available Online from 27 April 2024
  • Receive Date: 22 March 2024
  • Revise Date: 13 April 2024
  • Accept Date: 25 April 2024