|
Abstract
|
The aggravation of the urban heat island, especially during summer time, could affect the environment and the quality of life. Studying the dynamics of surface thermal energy and identifying its correlation with human-induced changes is essential for predicting environmental changes as well as policy-making in urban settlement planning. Increasing vegetation is one of the most effective strategies to reduce the effects of urban microclimate. In this regard, a research study was conducted to analyze the trend of surface thermal changes and the spatial correlation of vegetation greenness with this phenomenon due to urbanization and urban planning developments in Tehran city between 2003–2022. Satellite images of Tehran with clear sky were obtained using ASTER satellite in August 2003 and Landsat 8 satellite in August 2022. They were processed through various remote sensing algorithms using Envi software to extract spatial patterns of surface temperature and Normalized Difference Vegetation Index (NDVI) of the Tehran metropolitan area. Satellite outputs show that over the past two decades, the minimum surface temperature and average surface temperature have decreased by 3.67 °C and 0.47 °C, respectively, while the average NDVI has increased from 0.06 to 0.10. The spatial correlation estimate between NDVI and Land Surface Temperature (LST) in twenty-two districts of Tehran in the years 2003 and 2022 is 83% and 81%, respectively. The decline in correlation suggests a heightened influence of human activities and other physical factors associated with urban areas on the intensity of the urban heat island phenomenon.
|